Industrial Products – Kenny Randolph Parker, Charles Stuart Everett, Melvin Glenn Mitchell, Koushik Ghosh, Mounir Izallalen, Eastman Chemical Co
Abstract for “Molded articles made from a fiber-slurry”
Contoured articles are made in a mold using a fiber slurry. These articles are made from a mixture of cellulose fibers, cellulose ester and staple fibers. These articles can be used in many different applications, such as cups, lids or pouches and storage containers.
Background for “Molded articles made from a fiber-slurry”
“Recently, convenience foods such as fast food and casual dining have increased in popularity, which has led to a greater need for single-use packaging and containers. In the same way, consumers and manufacturers have become more conscious of the environmental impact of their products.
“There is a demand for non-persistent, environmentally friendly articles that can be used in many applications including food, beverage and packaging. The material would have desirable properties like strength, water resistance, durability, and environmental sustainability while in use. However, it would be quickly and without any environmental impact after disposal.
“In some embodiments of the invention, the contoured molded articles are formed from a fiber-slurry. The molded article includes a mixture of cellulose fibers as well as a cellulose ester.”
The present invention is a method for creating a contoured, molded article using a fiber slurry. The process involves: (a) making a fiber mixture consisting of cellulose fibers, staple fibers from cellulose ester, and at most one liquid;(b) contacting this fiber slurry with an a contoured molding mold; (c), forcing some of the liquid through the forming mould while retaining at minimum a portion the fibers on the contoured surfaces of the mold to form a contoured fibrous surface on the forming surface to allow for the formation of a liquid layer; (e) drying the contoured-formed article once it has been dry the wet-formed article to create the contoured mold article.
“In some embodiments of the invention, the use of fiber slurry to make a molded article is contemplated. The fiber slurry includes cellulose fibers and staple fibers that are cellulose ester.
“Composition containing cellulose fibers or synthetic cellulose fibers comprising of cellulose ester staple fibres is now available. The cellulose ester fibers must have one or more of the following characteristics: a denier per fiber (DPF) less than 3.0; a cut length less than 6 mm; a non-round form and/or crimped (referred to throughout as?Composition?). These Compositions can be found in any of the following process zones or steps. They also can be found in any vessel or pipe in a stock preparation or wet lay machine process. The Compositions may be present in feeds to, inside, or effluents of a hydropulper or any other blending vessel, refiner, a chest, a stuffbox, a hydrocyclone or a fan pump, in the pressure screen, on the wire and in the presses dryers sizing press, in the calender, sheets on rolls, in a broken vessel, in a calender or as consumer articles. The Compositions can also be found in wet-laid articles. These can also be prepared with the Compositions.
“The Compositions contain cellulose fibres and cellulose est fibers, at least a portion which are cellulose staple fibers
“Cellulose fibers” are those fibers that are not further chemically derivatized using functional groups. Cellulose fibers are made from virgin material or can be recycled.
“The CE staple fibers are synthetic fibers that are derivatives from cellulose obtained through a synthetic process. However, as used herein exclude the regeneratedcelluloses or other derivates cellulose-based such as rayon, viscose, and lyocell cellsulosic fibers.”
“A ?100% Cellulose Comparative composition? A composition in which 100% of the fiber component is cellulose fibers. It is also the same as a reference composition, including consistency, type of cellulose fiber, formulation ingredients and quantities as well as stock preparation conditions and conditions and refining conditions. If the reference is to either a sheet of wet-laid product, the 100% Cellulose Comparative Composition will also be a sheet- or wet-laid product. Alternatively, if the reference refers to a composition that contains both virgin and waste/recycle fibers, the 100% Cellulose Comparative Composition will also contain the same amount of virgin cellulose fibers to waste/recycle fibers.
“A ?cellulose fiber? “A?cellulose fiber” can be made from virgin or recycled fibers and can be fibrillated, non-fibrillated, or both.
“?Co-refining? “?Co-refining? Co-refined means that at most one cellulose fiber and one CE staple fiber have been refined together. Cellulose fibers and CE staple fibres in a feed stream to refiners are considered co-refined. A co-refined CE fiber refers to a cellulose fibre that has been refined in the presence a CE staple fibr. A co-refined CE fiber signifies that a CE staple fibre has been co-refined with a cellulosefiber.
“The ?consistency? “The consistency” is a measurement of the solids content in a liquid stream. It can be measured by drying a representative of the liquid stream and then dividing the weight from the oven dried solids to that of the representative sample.
“A ?machine direction? “A?machine direction? The direction in which the web moves on a machine that is wet laid. The?cross direction? The?cross direction? The direction that crosses or is perpendicular with the MD of the sheet or web.
“A ?non-woven web? A web made of fibers without the use of knitting or weaving operations.
“A ?Post-Addition? “A?Post-Addition? This is a mixture of fibrillated or refinedcellulose fibers and CE staple fibres. The CE staple fibers are only combined with the other cellulose materials after the cellulose has been refined. If the feed to refiners does not contain CE staple fibres, the CE staple fibers will be deemed not to have co-refined. The Post Addition Composition can be used as a comparison. However, the CE staple fibers do not occur during refinement and are only combined with cellulose fibres after the cellulose has been refined. The Post Addition Composition’s cellulose fibers are refined in the same conditions as the reference Composition. In other words, the consistency of cellulose fiber furnish that is fed to the refiner will be the same consistency as the reference Composition. After the cellulose fibres have been refined, the CE staple fibers are added into the refined cellulose furnish. The consistency of the blend will be adjusted to match the consistency of reference Composition. Post-Addition CE staple fibres are CE staple fibrs that have been added to cellulose after the cellulose has been refined.
“A ?thick stock? A stock with a minimum solids content (or stock consistency), of 2.0 wt. %.”
“A ?thin stock? A stock with a solids content (or stock consistency), less than 2.0 wt. %.”
“Virgin” is a term that refers to stock or fibers. “Virgin” refers to stock or fibers that are not being used for their intended use. However, the fibers must not have been inked or de-inked when they are contained in a web or other article.
“A ?wet laid non-woven product? A product weighing at least 50 wt. Fibers with a L/D greater than 300 have a minimum of 5%.
“Waste/recycle” is a term that refers to products that have been processed into fibers or stock. “Waste/recycle” refers to fibers and stock made from products that have been printed or used for their intended purpose.
“A ?wet laid process? A process where fibers are dispersed in liquid, such water, onto a wire, drying matt or filter. The liquid is then drained or removed to form the web. It is possible to distinguish a wet laid process from one that uses air-laid, carding, or needlepunch methods.
“A ?wet laid product? or ?wet laid web? A product that is made using a wet-laying process. It can be non-woven and also contain paper-like products with at least 50 wt. A minimum of 3% of fibers have a L/D of 300.
“The word ‘can? is equivalent to?may? “The word?can?? is equivalent to the word?may? is equivalent to?may? . . .?”
“Whenever a claim refers to a compositional characteristic that is quantified by a comparison between an inventive composition and a comparative (e.g. A 100% cellulose comparative or Post Addition composition is sufficient to satisfy the claimed feature for purposes of infringement.
“Raw Materials: Cellulose Fibers”
“Cellulose fibers are one of the components in the Composition. Cellulose fibers are made from cellulose. The unbranched polymer D-glucose (anhydroglucose), which is obtained from plants, is included in the term cellulose. Cellulose and cellulosic fibres contain at least one unbranched polymer of D-glucose. Optionally, they can also include hemicellulose or lignin. Each cellulose polymer chain associates to form thicker microfibrils, which in turn associate to form fibrils that are arranged into bundles. When viewed under a scanning electron microscope or light microscope, the bundles create fibers that can be seen as part of the plant cell walls.
“Hemicellulose” refers to a heterogeneous collection of low molecular weight carbohydrate monomers that are linked with cellulose in wood. Hemicelluloses are typically branched polymers in contrast to cellulose, which is a linear type of polymer. D-glucose and Dxylose are the principal simple sugars that can be combined to make hemicelluloses.
Lignin is an aromatic complex polymer that makes up about 20% to 40% wood, where it occurs as an inorganic polymer. There are three main types of lignins: softwood, coniferous (gymnosperm), hardwood and grass (monocotyledonous giosperm). Softwood lignins are often characterized as being derived from coniferyl alcohol or guaiacylpropane (4-hydroxy-3-methoxyphenylpropane) monomer. Hardwood lignins contain polymers of 3,5-dimethoxy-4-hydroxyphenylpropane monomers in addition to the guaiacylpropane monomers. The grass lignins contain polymers of both of these monomers, plus 4-hydroxyphenylpropane monomers. When isolated using similar methods, hardwood lignins can be more heterogeneous than softwood lignins.
“Representative sources for cellulose fibers include but aren’t limited to wood and non-wood plant sources such as cotton, cereal straws, flax and flax. You can get cellulose fibers from virgin or recycled cellulose fibers or any combination of both.
Table 1 below shows the typical fiber lengths of a variety pulped cellulosic fibres.
“Hardwood and non-wood fibers can be combined to create a unique article that has the desired strength, whiteness, writing surface, or other characteristics. Recovered fibers are ideally suited for applications such as paper, packaging and newsprint because of their mixed characteristics. Table 2 shows examples of softwoods and hardwoods from different sources and describes their characteristics.
TABLE 2 – Features Hardwood Trees Softwood treesnType of Oaks and poplarsnTree birches or eucalyptus are used for Finland, Norway, and papermaking. The Americas have Sweden. Softwoods (SBHK), which are used for strength, is found primarily in the southeastern region (NBSK) in Canada. Eucalyptus is Softwood for large bulk. It is mainly grown in Brazil. (SBSK is found in thenpapermaking. southeastern USA.\nType of Short Long\nfiber\nAverage 1 mm 3 mm\nlength of\nfibers\nFeatures Achieving bulk, smoothness, Providing additional strength.\nopacity Also suitable for writing and\nprinting\nTypical Writing papers, printing Shipping containers, grocery\nproducts papers, tissue papers bags, corrugated boxes”
Kraft softwood fiber is a low-yield fiber that is made from coniferous materials. It includes Northern and Southern softwood Kraft fibre, Douglas Fir Kraft fiber, and so on. Kraft softwood fibers have a lignin percentage of less than 5 % by weight. They also have a shorter length weighted fiber length than 2 mm and a longer arithmetic fiber length than 0.6mm. Kraft hardwood fiber is made from Eucalyptus hardwoods using the Kraft process. It generally has a lignin percentage of less than 5% by weight. Kraft hardwood fibers are typically shorter than Softwood fibers. They have a weighted average fiber length less than 1 2/3 inches and an arithmetic mean length less than 0.5 or 0.4 millimeters.
“Waste/recycle fibre can be used to provide cellulose fiber for the Composition or may be added to virgin fibers. Any suitable waste/recycle fibre can be used. However, waste/recycle fibr with low groundwood levels, such as office waste containing less than 15% or 10% by weight of lignin, may be useful. Newsprint waste may contain high amounts of lignin (e.g., more than 10 wt. % or 20-40 wt. % lignin.”
“In any of the above-described embodiments, cellulose fibers can either be fed to a Hydropulper as a pulp containing liquid or dried pulped material (e.g. As sheets or bales made from pulpedcellulose. The wet-laying process can be used for any method of obtaining pulp. A pulp is a mixture of water and plant-based cellulose fibers. It can be made by any one of many pulping methods that are familiar to those who have experience in the art, such as PGW, PGW, TMP or CTMP. As described further below. A source of cellulose is needed to make pulp. Wood sources are first debarked, then chipped and optionally pithed. To make pulp, the chipped wood can be subjected either to chemical or mechanical processing. A mechanically processed pulp is used in many wet-laid processes such as paper, tissue, and cardboard manufacturing. The refining and treatment of wood chips under atmospheric conditions, steam treatment or chemical treatment, is called mechanical pulp. The mechanical pulping process produces a mixture fibers and fragments of fibers, but does not remove the lignin. This results in a lower quality paper that is more prone to discoloring over time. Examples of suitable mechanical processes for obtaining pulp include the bleached chemical thermomechanical pulp (BCTMP) process, the pressure groundwood pulping process (PGW), thermomechanical pulp processes (TMP), chemithermomechanical pulp processes (CTMP) and alkaline peroxide mechanical pulp processes (APMP). PGW pulp uses all wood. It is suitable for newsprint production and other applications where high quality pulp can be obtained over a long life span. TMP pulps are stronger than PGW and can be used in newsprint. They also have applications in tissue and paperboard. CTMP pulps are a mixture of mechanical processing and chemical processes. The pulp is softened by adding sodium sulfite carbonate, hydroxide or hydrogen to it.
The pulp can then be further processed in a mill to remove any additional impurities by screening, washing and de-knotting.
A full chemical pulp process uses a combination of pressure, steam, and cooking liquor to dissolve lignin from the cellulose fibers. Chemical pulp papers are often called wood-free papers. This is because they don’t contain mechanical pulp lignin which can cause deterioration over time. To make white paper, the pulp can be bleached. Chemical pulps are easier to bleach than mechanical pulps, as the chemical processes remove most of the lignin from the cellulose source.
“The ability of pulp to reflect monochromatic light is a measure of its whiteness. This standard (usually magnesium oxide) is used to determine the whiteness. The Zeiss Elrephro reflectancemeter, which is a diffuse light source, is a common instrument. Unbleached Kraft pulp can be as low as 15% Elrephro units, while fully bleached sulfite pulps may test up to 94%.
Unbleached pulps have a wide range in brightness values. Chemical pulps produced by the sulfite process are brighter, at up to 65%. Semichemical pulps made with Kraft, soda, and semichemical processes can be quite dark.
The pulp can be bleached, regardless of whether it is chemically or mechanically processed. Chemical means include chlorine dioxide, oxygen and peracids as well as hydrogen and alkaline peroxide. It is preferred that oxygen be used in bleaching and that chlorine is avoided. Bleached pulps that have been treated without the use of elemental chlorine or hypochlorite is known as (ECF), Elemental Chlorine-Free. Mills can go to “TCF” or Totally Chlorine-Free for a more strict bleaching process.
“Table 3 contains a table that lists the different types of pulp.
“TABLE 3\nAbbre-\nviation Type Description\nMechanical Pulps\nRMP Refiner Mechanical Pulp Raw wood chips refined and dis-\ncharged at atmospheric pressure\nTMP Thermomechanical Pulp Steamed raw chips refined unpres-\nsured and again under no pressure.\nCMP Chemical Mechanical Chemically treated chips refined at\nPulp atmospheric pressure.\nCTMP ChemiThermoMechanical Steamed, chemically treated chips\nPulp refined under pressure and again\nunder no pressure\nFull Chemical Pulps\nSo Soda Pulp Chips cooked under pressure with\nstrong NaOH\nK Kraft Pulp Chips cooked with strong NaOH\nplus Na2S”
“Mechanical pulps are used in the production newsprint and magazines. Full chemical pulps can be used to make printing/writing paper and sanitary/household packaging material.
“Waste/recycled paper pulp can also used in Compositions to make wet-laid products. You can recycle paper/board made from chemically or mechanically manufactured pulp. Mixing the waste paper/board with water can break the hydrogen bonds and separate the fibers. Although recycled papers can be made with 100% recycled materials, or mixed with virgin pulp, they are generally not as strong and bright as papers made from the former. For strength and quality, most paper made from recycled paper/recycled paper has a small amount of virgin fiber.
“There are two types of waste/recycled fibre, and any one or both can be used in the Composition as a source for cellulose fiber:
Mill broken or internal mill waste includes any substandard or grade-change papers made in the paper mill. These materials are then re-pulped into paper by the manufacturing system. This out-of-specation paper cannot be sold and therefore is not often classified as genuine recycled fiber. However, most paper mills have been recycling their waste fiber for years, long before recycling was common. This category of waste is called “broke” for clarity. pulp is not considered waste/recyclepaper or waste/recyclepulp as it is used in this description.
“In sum, the pulp sources containing the cellulosic fiber to make the Compositions and wet laid products are not limited, and may comprise a blend of conventional fibers (whether derived from virgin pulp or waste/recycle sources) and high coarseness lignin-rich tubular fibers, such as bleached chemical thermomechanical pulp (BCTMP), thermomechanical pulp (TMP), chemithermomechanical pulp (CTMP) alkaline peroxide mechanical pulp (APMP) and the groundwood pulp (GWD), in each case bleached or unbleached, deinked, and can be processed chemically by the Kraft method to make Kraft pulps (both sulfate and sulfite) and bleached Kraft pulps. The recycling stage may bleach recycled pulps. To produce a bleached pulp material, any of the pulps mentioned above that have not been previously bleached may be bleached in the manner described herein.
The Composition can be used as a furnish or can be used in any other composition before refining. It can contain virgin nonfibrillated cellulosic fibers, refined cellulose fibres, and can also contain co-refined cells (which may include broken), and can also include a mixture of virgin and recycled non-fibrillated cellulosic fibers. One or more of the above-mentioned embodiments reveals that cellulosic fibre is obtained from wood. This can be softwood or hardwood.
“In any one of the above embodiments, the Composition includes pulpedcellulose fibers or is made by adding pulpedcellulose fibers to the CE staple fibres.
“In any one of the above-mentioned embodiments, pulpedcellulose fibers are mixed with CE staple fibers or are present within the Composition or in the wet laid products that contain the Composition or are obtained from the Composition in an quantity of at least 60 wt. % or more than 70 wt. % or less than 71 wt. % or at least 72 Wt. % or at least 75 Wt. %, or at most 80 wt. %, or at most 90 wt. % or at least 95 Wt. % or at least 98 Wt. %, or at most 99 wt. % or 100 wt. % based on the total weight of all cellulose fibres (not including CE staples fibers) in the Composition/wet laid product. 100 wt. %, there are no unpulped fibers of cellulose.”
“In at least 60 wt., wood pulp can be found in the Composition in one or more of the above-mentioned embodiments. % or more than 70 wt. % or 75 wt. %, or at most 80 wt. %, or at most 90 wt. % or at least 95 Wt. % or at least 98 Wt. %, or at most 99 wt. %, or at least 99 wt. % in each case is based on the total weight of all cellulose fibres (not including CE staples fibers) in the Composition/wet laid product. Non-pulped and nonwood pulped can be used for the remaining cellulose fibers. Desirably, these cellulose fibers are pulped from non-wood plant-based resources.
“In any one of the above-mentioned embodiments, nonwood cellulose fibers may be present in the composition or wet laid products containing the composition in a quantity of less than 95 wt. % or less than 80 wt. % or not more that 60 wt. % or not more that 50 wt. %, or not more that 40 wt. %, or not more that 30 wt. %, or not more that 25 wt. %, or not more that 20 wt. %, or not more that 15 wt. %, or not more that 10 wt. % in each case, based on the total weight of all cellulose fibres in the Composition/wet laid product. The remaining cellulose fibers are wood-sourced cellulose fibres or, if desired, pulped wood-sourced cellulose fibrs. This embodiment, or any other embodiment, can have a minimum of 30 wt. % or at most 40 wt. % or at least 50 Wt. % or at least 60 Wt. %, or at most 70 wt. %, or at most 80 wt. %, or at most 90 wt. % or at least 95 Wt. % based on the total weight of all cellulose fibres in the Composition.
“In any embodiment, or in any of the embodiments, the Composition or the effluent from an refiner or the Composition or wet laid products that contain or are obtained from the Composition must not exceed 5 wt. % or not more that 3 wt. % or less than 1 wt. % or less than 0.5 wt. % or 0.25 wt. % or less than 0.01 wt. % or 0.01 wt. % or less than 0.01 wt. % or less than 0.0001 wt. Based on the Composition’s weight, % of fiber bundles.
“In any embodiment, or in any of the above embodiments, the Composition includes virgin non-fibrillated and/or co-refined virgincellulose fibers in an amount of at minimum 25 wt. % or at least 50wt. % or at least 50 wt. % or at least 60 Wt. %, or at most 70 wt. %, or at most 80 wt. %, or at most 90 wt. % or at least 95 Wt. % or at least 95 wt. %, or at least 98 wt. Based on the total weight of all cellulose fibres in the composition, %.
“In another embodiment, or in any other embodiment, the Composition contains either waste/recycled cellulose fibers or co-refined cellulose fibers in an amount of at minimum 25 wt. % or at least 50 Wt. % or at least 50 wt. % or at least 60 Wt. %, or at most 70 wt. %, or at most 80 wt. %, or at most 90 wt. % or at least 95 Wt. %, or at most 98 wt. % or 100 wt. Based on the total weight of all cellulose fibres in the composition.
“The Composition may also contain a mixture of virgin cellulose fibers as well as waste/recycled cellulose fibers.
“The Composition, as mentioned above, contains at least one cellulose fiber. It is desirable that the Composition contains at least one cellulose fiber in any embodiment.
A virgin non-fibrillated cellulose fiber is one that hasn’t been subjected any refining operations at all or that has not been beat or refined after the preparation of a pulp product. It is either ready for use or has been received to a wet lay process facility (e.g. Ready to be used as a feed for a stock preparation area in a wet-laid process. The pulp may not have the required amount of fibrillation to the cellulose fibers during the pulp preparation stage. However, non-fibrillated fibers are fibers that have not been subjected either to beating or refining. Many times, the amount of fibrillation that was imparted during pulp preparation is not sufficient to make a wet-laid product suitable for use. The process of making pulp from wood, or other plants as described in the above description is not included in the wet laid process. TMP, TMP CTMP, APMP and GWD are all examples of the wet laid process. Some of these methods can cause minor fibrillation of the cellulose. However, this is not enough to produce useful wet-laid products. As discussed below, compositions that contain virgin non-fibrillatedcellulose can be useful feeds for a refinery operation.
“Virgin fibrillatedcellulose fibers” are cellulose fibres that have been pulped and are then subject to a refinement operation to fibrillate them.
“Co-refined Cellulose Fibers” are those in which the cellulose fibres have been fibrillated under the control of a refiner with the addition of CE staple fibers. Co-refined fibers of cellulose can be virgin, recycled, or a combination of both. The wet-laid products that contain or are obtained from Post Addition Compositions have been shown to be inferior in certain respects. We will discuss this further below.
“The Compositions may use either fibrillated waste/recycled cellulose fibers or not. However, in most cases the fibers were already fibrillated when they were made as virgin products.”
“Any reference to a composition includes cellulose that is present in any of the following: a) or b) before refining and b), c), and/or (d) after refining.
“Raw Materials”: Cellulose Ester Fibres
“The cellulose ester staple fibre (?CE staple fiber)” “The cellulose ester staple fiber (?CE staple fiber) is a type of CE polymer. The suitable CE polymers are cellulose derivatized using a reactive compound to produce at least one ester at the hydroxyl site of the cellulose backbone. These include cellulose, cellulose diacetate and cellulose triacetate. While cellulose acetate is the focus of this article, it can also be used as a reference. It should be noted that the fibers can be made from any combination of the cellulose acid esters and mixed esters. U.S. Pat. describes a variety of cellulose esters. Nos. Nos. Regenerated cellulose (e.g. rayon, viscose or lyocell), and the fibers therefrom are not considered CE polymers or CE staple fibres as used herein.
“The CE staple fibers in one or more of the above embodiments are desirable virgin CE staple fibres. Cellulose ester fibers derived from other sources can be contaminated with additives and printing material. For example, cellulose ester fibers from cigarette filters can be contaminated with plasticizers like triacetin. These plasticizers, as we will see, can cause agglomeration or flocculation of resulting webs. If cellulose ester fibers are printed with material, it is undesirable.
“In any one of the above embodiments, the CE staple fibres are not to be refined or non-fibrillated after they have been combined with cellulose fibers or before being fed to a refiner. The Composition may contain both cellulose fibers as well as non-fibrillated CE staple fibers. This means that the CE staple fibres have not been refined to fibrillate them. The process of cutting filaments for the CE staple fibres is not considered to be a refining or fibrillating process. The CE staple fibres are not separated from cellulose fibers. However, the mixture will be subject to refining or the addition of non-fibrillated CE fibers after the cellulose fibrils have been refined. In each case, the invention will produce one or more effects. Non-fibrillated CE staple fibres are those that contain less than three fibrils/staple, not more then two fibrils/staple, not more or less than one fibril/staple, not more or less than 0.5 fibril/staple, not more or more often than 0.1 fibril/staple, not more or more frequently than 0.05 fibril/staple, not more or more commonly than 0.01 fibril/staple, not more or more regularly than 0.001 fibril/staple, not more, not than 0.0001 fibril/staple, not aple fiber or, not, not, not, not 0.01 fibril/staple, not, not, not, not, not, not, not, not, not, not, not over, not, not, not, not, not, not, not, not, not more or, not, not, but not, not more, not than, not more, not than, not mehr failing to be below 0.0001 fibril/staple or more or more or more or more or more or more or more or more or more or more or more or more or more or more or more or preferably besides an averagedo 5.0001 fibril/staple or more than 0.0001 fibril/staple or more than a non-fi a averaging get Koch apparently prioritize privat A non-refined CE staple fibre is also available. This means that it has not been refined. A composition can contain CE staple fibers that are either nonfibrillated or non-refined. The following examples show that compositions can be made at any stage prior to refining. They may include CE staple fibers that are either non-fibrillated or not-refined or both nonfibrillated or nonrefined. The combination of CE staple fibres and cellulose esters can be refined to make the CE staples non-fibrillated. However, they are no longer considered to be non-refined.
“The cellulose ester may have a degree or substitution that is not restricted, but it is desirable to have a range from 1.8-2.9. The term “degree of substitution” is used herein. Alternatively,?degree of substitution? The average number of acyl substitutes per anhydroglucose-ring of the cellulosepolymer is 3.0. The degree of substitution for cellulose esters used in the formation of fibers may be as low as 1.8 or 1.95 or 2.0 or 2.05, or 2.2 or 2.3 or 2.8 or 2.9 or less than 2.7 or 2.8 or more that 2.7 or 2.8 or more then 2.8 or more about 2.9 or more or more. Or not more or less than 2.55, or 2.55, or 2.55, or 2.55, or 2.5 or 2.5 or 2.5 or 2.5 or 2.5 or 2.4 or 2.35. At least 90 or 91 or 93 or 95 or 98 or not more than 2.9 or 2.8 or not more than 2.7 or not more that 2.6 or not more than 2.55, or not less then 2.55, or 2.45, or 2.25, is desirable. Acetyl groups can be found in at least 1, 5, 10, 15, 25, 30, 35, 45, 50 or 55 percent, and/or not more that 99 percent, or more than 90 percent, or more than 85, not more then 80, not more 75, not more over 70%, or less than 99 percent of total acyl substitutes. It is desirable to have a greater than 90 percent weight percentage, or greater 95%, or higher than 98%, more than 99.9%, or up to 100 wt. Acetyl substitutes (C2) make up 5% of total acyl substitutions. The cellulose ester cannot contain acyl substitutes with a carbon number greater than 2.
“In any embodiment, or any of these embodiments, the DS for the cellulose esterpolymer is not greater than 2.5 or less than 2.45. The best CE staple fibers are both industrially and home-compostable when they have a DS not exceeding 2.5. Also, CE staple fibers made from cellulose ester polymers with a DS below 2.5 are soil biodegradable according to the ISO 17566 method.
“The cellulose ester may have a weight-average molecular weight (Mw) of not more than 90,000, measured using gel permeation chromatography with N-methyl-2-pyrrolidone (NMP) as the solvent. The cellulose ester might have a molecular mass of 10,000 in some cases. This is measured using gel permeation chromatography with N-methyl-2-pyrrolidone (NMP) as the solvent.
“Desirably the CE staple fibers can be mono-component fibers. This means that there are no distinct phases such as islands, domains or sheaths made of other polymers in the fiber. A mono-component fiber may be made entirely of CE polymers or can contain a mixture of CE polymers and another polymer. At least 60% of the CE staple fibres’ composition must be CE polymers. These percentages are not inclusive of spin or cutting finishes that were applied to the filaments after they have been spun, or any other additives with a number average molecular mass less than 500.
“The cellulose ester can be made by any method. However, the CE staple fibers should be obtained from filaments that have been spun by solvent. This is different from precipitation or emulsion flashing. To make a “solvent dope”, the cellulose ester flake can be dissolved in solvents such as acetone and methyl ethyl ketones. This can be filtered and passed through a spinnerette in order to make continuous cellulose ester filaments. Sometimes, it can reach 3 wt. %, up to 2wt%, up to 1weight percent, up to 0.5wt. % or up to 0.25 Wt. % or as low as 0.1 wt. Based on the weight of dope, a % of titanium dioxide or another delusterant can be added to dope before filtration. Depending on the desired properties of the fibers and their ultimate end use, the amount of titanium dioxide added may vary from 1% to 0.1 wt. Continuous cellulose ester filaments can then be cut to the desired length. This results in CE staple fibers with low cut length variability and consistent L/D ratios. They are also available as dry fibers. The precipitation-based cellulose ester forms have a low length consistency, are random in shape, have wide DPF distributions, have wide L/D distributions, can’t be crimped and are not supplied wet.
“In some cases, other additives to the cellulose ester may be added to the solvent dope/flake used to make CE staple fibers. These additives may include, but not be limited to: plasticizers and antioxidants, thermal stabilizers or acid scavengers. Inorganics, pigments and colorants. The CE staple fibers described herein may include at most 90 or 90.5 or 91 or 92.5 or 93 or 95 or 94.5 or 96 or 96.5 or 97 or 98 or 96.5 or 97 or 98 or 99.5 or 97 or 97 or 98 or 99.5 or 97 or 98 or 99.5 or 99.9 or 99.995, or 99.999 percent of cellulose ester based on the fiber’s total weight. Fibers can contain or include no more that 10, or less than 90.5, not greater than 8 or more, not less than 7 or more, not higher than 6 or more, not higher than 6.5, not greater than 7 or more, not over 6.5, not above 7 or more, not at all 95, not at least 93.5, not at least 92.5, not at least 93, not just 94, not only 95, not at minimum 95.5, not below 96, not above 96.5, not beyond 97, not cellulose ester, not cellulose esters, but not cellulose ester fibre, and not cellulose, cellulose ester, not cellulose, not cellulose, not cellulose, cellulose ester, not cellulose, not cellulose, not cellulose, not cellulose, not cellulose, not cellulose, not cellulose, not cellulose, cellulose, not cellulose, not cellulose, not cellulose, not cellulose, not cellulose, not cellulose, not, not cellulose, cellulose ester, cellulose ester, cellulose ester, cellulose ester fiber, cellulose, not cellulose, cellulose, not cellulose, cellulose, cellulose, cellulose ester, cellulose, cellulose, cellulose, cellulose, cellulose, cellulose ester, cellulose, cellulose, cellulose ester, cellulose ester, cellulose ester, cellulose ester, cellulose ester cellulose ester cellulose ester cellulose ester cellulose ester cellulose cellulose ester cellulose cellulose, cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose res cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose s cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose, cellulose cellulose sa cellulose cellulose ester cellulose cellulose cellulose cellulose cellulose ester cellulose cellulose sa cellulose cellulose s s cellulose s s s s sta cellulose s spy sa s sp
The solvent can be extruded through multiple holes at the spinnerette to form continuous cellulose ester fibers. The spinnerette allows filaments to be drawn into bundles of hundreds, or even thousands, of individual filaments. These bundles or bands may contain at most 100 filaments or 150 filaments or at the very least 200 or 250 or 350 or 350 or 400 or more than 1000 or 900 or 800 or 750 fibers or not over 700. You can operate the spinnerette at any speed that produces filaments. These filaments are then assembled into bundles of desired size and shape.
Multiple bundles can be assembled to form a filament band, such as a crimped or uncrimped band. A filament band can be any size. In some embodiments, it may have a total denier of at most 10,000 or 15,000 or 30,000 or at minimum 45,000 or at most 40,000 or at best 75,000 or at worst 50,000 or at lowest 150,000 or at the least 200,000 or at minimum 250,000 or at least 300,000. Alternately, and in addition, the total denier for the tow band cannot exceed about 5,000,000 or less than 4,500,000 or less than 3,000,000 or more that 3,000,000 or more then 2,000,000 or more or more or more or more or more or more or more or more or more or more or more or more or more or more or more or at least 100,000 or at least 150,000 or at most 250,000 or at least 300,000.
“We found that any one of the CE staple fiber cut lengths, shapes, denier per fiber, and crimp can influence one or more properties wet laid products containing or obtaining by the Compositions. These include surface smoothness and water drainage rates, absorbency and stiffness even with smaller pore sizes, nonwoven densities, light-weighting and rewettability, softness and tensile strengths. Below are detailed descriptions of each of the CE staple fiber characteristics.
The individual filaments that are spun in a generally longitudinally aligned fashion and form the tow band are of a specific size. Linear denier per filament is the weight in g of 9000m fiber length, or DPF of CE filaments and corresponding CE staple fibers. It should be within a range between 0.5 and 3. There are many methods for measuring the filaments. These include ASTM 1577-07 using FAVIMAT vibroscope procedure, if the filaments can be obtained from which staple fibers were cut, or width analysis using any optical microscopy, Metso, or other convenient optical microscopy.
The DPF can also be used to determine the maximum fiber width. The fiber’s maximum width is determined by its longest outermost dimension. If the fiber is not round, it is possible to measure the longest outer diameter by spinning the fiber. The table 4 shows a handy correlation between DPF and maximum widths (or outer dimensions) of fibers. This is true regardless of their shape or multi-lobal configurations.
“TABLE 4nApproximatenDPF Width (microns)n1.6 22,n2.0 25,n2.4 28,n2.8 30,n3.2 32n3.634n4.0 36”
“Desirably the DPF ranges of the filaments and of the CE staple fibres are 1.0-2.8 or 1.0-2.5 or or 1.0-2.2 or 1.0-1.2.1 or 1.0-2.1 or more desirable from 1.0-2.0 or 1.0-2.999 or 1.1-1.9 or 1.1-1.1.9 or 1.1-1.8. Handsheets made from the Compositions with CE staple fibers with a DPF below 3 have higher air permeability than those made with fibers with 3 DPF or less.
“In any other embodiment, or in any of the above embodiments, the maximum fiber width is less than 31 microns or not over 30 microns or more than 27 microns or more than 26 microns or more than 25 microns or more than 25 microns or more than 25 microns or more that 24.5 microns or more than 24 microns. One embodiment, or any of the above mentioned embodiments, has a minimum width or diameter of fibers that is greater than 1 micron (1000 nm).
“In any one embodiment, or any of these embodiments, at minimum 70% or at most 80%, or 85%, or more than 90%, or a minimum of 95%, or a minimum of 97% of the CE-styl fibers have a DPF that is within +/-20% of any of the above mentioned DPF. Alternately, at minimum 70% or 80% or at most 95% or 97%, or a minimum of 95% or 97%, the CE staple fibres have a DPF that is within +/-15% of any of the above mentioned DPFs; or at the least 70% or 80% or at the least 85% or at the least 90%, or a minimum of 95% or at the least 97%, the CE staple fibrs have a DPF that is within +/-10% of any of the DPF. At least 85% or 90% or at most 95% or at minimum 97% of CE staple fibers has a DPF of within +/-15% or within +/-10% of any of the above mentioned DPF.
“In any one of the above embodiments, the DPF may have a narrow distribution span that meets the following formula:
“d ? ? 90 – d? ? 10 d ? 50 * 100 ? S”
“Where d is calculated based on the median DPF. d90 is where 90% of fibers have DPFs less than target DPF. d10 is where 10% of fibers has DPFs less than target DPF. d50 is where 50% of fibers have DPFs less than target DPF. Lastly, S is 40% or 35% or 30% or 25% or 20% or 15% or 10% or 7%.
“The spinnerette’s individual cellulose ester filaments and the CE staple fibres may have any transverse cross-sectional form. Examples of cross-sectional shapes are, but not limited to, the round or non-round (non-round). Non-round shapes include Y shapes or other multi-lobal forms such as I-shaped (dog bone), closed C shapes, X-shaped and crenulated. A cellulose ester filament or CE staple fiber may have a multi-lobal cross sectional shape. It could have 3, 4, 5, 6, or more lobes. The filaments can be symmetric along one, more, two, more, three, or more or four or more of the axes. In other cases, they may be asymmetrical. The term “cross-section” is used herein. The term “cross-section” generally refers to the transverse length of the filament, measured in a direction that is perpendicular with the direction of filament elongation. Quantitative Image Analysis can be used to measure the cross-section of the filament. Staple fibers will be similar in cross-section to the filaments they were formed from, but without deforming them mechanically.
“In any one of the above embodiments, desirable, the shape and size of the CE staple fibre is:
Round-shaped CE staple fibers are known to reduce the air permeability of wet-laid products. A round-shaped fiber, such as a cellulose composite, can be used to achieve a minimum density of 0.450 g/cc. This will significantly improve water permeability. Shape factor less than 1.25 or made from filaments solvent spun through circular holes or targeted as round.
“In any one embodiment, or in any of these embodiments, at minimum 70% or at most 80%, or 85%, and at least 90% or at the least 95% or at the least 97% or at the least 99.9% of the CE staple fibres have the specified shape.”
After multiple bundles have been assembled into a filament yarn, it can be passed through a Crimping Zone where a pattern wavelike shape may be imparted at least to a portion or substantially to all of the individual filaments. The filaments may not need to be crimped in some cases. In these cases, the uncrimped filaments can be passed from the spinnerette directly to a drying area. The crimping area must contain at least one crimping device that can mechanically crimp the filament yarn. The crimping of filament yarns is not done by chemical or thermal means (e.g. steam, hot water baths or chemical coatings), but rather mechanically using a suitable Crimper. A?stuffing container? is one example of a suitable mechanical crimper. Or a?stutterbox? A crimper that uses a number of rollers to create friction. This causes fibers to buckle and forms crimps. You may also find other types of crimpers suitable. U.S. Pat. describes some examples of equipment that can impart crimp to filament yarns. Nos. Nos. “In some cases, the crimping may be done at a speed of 50 m/min (75. 100. 125. 150. 175, 200. 225. 250. m/min and/or not more that 750 m/min (475.450.425; 425.400, 400, 375. 350, 325 or 300 m/min).
“The average effective length of the crimped CE staple fibers is 85 percent in one embodiment and any other embodiments. The effective length is the distance between two points on a fiber. While the actual length is the fiber’s length end-to-end, if it were straightened perfectly, the actual length is the fiber’s maximum dimension. The fiber’s effective length will be the same length as its actual length if it is straight. If a fiber is straight, its effective length is equal to its actual length. The actual length is the length of the fiber from end-to-end if it was perfectly straightened. The average effective length of crimped fibers in one embodiment, or any of the embodiments herein, is not greater than 80.
Low DPF CE staple fibers are more susceptible to breaking when they are cut from the filaments or further processed than the normal frequency of Crimps imparted by higher denier fibers commonly used in cigarette filter. Crimping can be used to improve cohesion and entanglement of the CE staple fiber with cellulosic and other fibers. Due to the low DPF fibers, it is important to reduce fiber breakage during cutting to staple, when they are further processed, or when they are combined with cellulosic fibres. Crimping also helps to maintain a high level of retained tenacity. The term “retained tenacity” is used herein. The ratio of the tenacity a crimped filament or staple fiber to the tenacity a similar but uncrimped filament, expressed in percent. A crimped fiber with a tenacity (g/denier), of 1.3 grams would have an 87 percent retained tenacity compared to a fiber that has a similar but uncrimped tenacity (1.5 g/denier).
“In any one of the above embodiments, the crimped cellulose ester filaments can retain tenacity of at most about 40% or at minimum 50% or at the least 60% or at the least 70% or at the least 75% or at the least 75% or at the least 80% or at the least 85% or at the least 90% or at the least 95%.”
“Crimping can be done such that continuous filaments from CE staple fibers and/or CE staple fibers have a minimum crimp frequency of at most 5, 7, 10, 12, 13, 15, or 17, or up until 30, or 27 or 25, or 23, or 20, or 20 or more crimps per in (CPI) according to ASTM D3937-12. A higher than 30 CPI can lead to excessive breakage when cutting filaments to staple at small cut lengths. This also reduces their retained strength. A crimp will occur when the CE staple fibers are cut at shorter lengths than 5 CPI. The average CPI of the filaments used in making CE staple fibers should be between 7 and 30 CPI or 10-30 CPI or 10-25 CPI or 10-25 CPI or 10-25 CPI or 10-25 CPI or 10-20 CPI or 12-20 CPI or 12-25 CPI or 12-24 CPI or 12-24 CPI or 12-25 CPI or 12-24 CPI or 12-20 CPI or 12-20 CPI or 15-30 CPI or 15-27 CPI or 15-27 CPI or 15-25 CPI or 15 or 15 or 15 or 23 CPI or 15 or 20 CPI or 15 or to 23 CPI or 15 or 20 CPI or 15 or 20 CPI or 15 or 20 CPI or 15 or 20 CPI or 15 or 20 CPI or 15 or to 23 CPI or 15 or 20 CPI or 15 or 20 CPI or 15 crimp to 23 CPI or 15 or 20 CPI or to 20 CPI or to 20 CPI or to 20 CPI or 15 or 23 CPI or 15 or 20 CPI or 20 CPI or 23 CPI or 15 or 23 CPI or 20 CPI
“In any one of the above-mentioned embodiments, the ratio crimp frequency CPI/DPF can be greater or less than 2.75:1, 2.80:1, 2.90:1, 2.95:1, 2.95:1, 2.95:1, 2.95:1, 2.95:1, 2.95:1, 3.05:1, 3.05:1, 3.20:1, 3.20:1, 3.15:1, 3.20:1, 3.15:1, 3.20:1, 3.20:1, 3.20:1, 3.25:1, 3.40:1, greater that 3.40:1, greater then 3.45:1, greater or 3.45:1 or more than 1.45:1 or 3.45:1 or 3.45:1 or higher than 3.45 or 3.45:1 or 3.45:1 or 3.45:1 or 3.45:1 or 3.45:1 or 3.45:1 or 3.45:1. This ratio can be higher in some cases. For example, it may be greater than 4:1 or greater that 5:1 or greater that 6:1, or more than 2.90:1, or more than 2.95:1, or more than 3.05:1, or less than 3.20:1, or less than 3.15:1, greater than 3.25:1, greater than 3.15:1, greater than 3.00:1, greater than 3,05:1, greater than 3,05:1, greater than 3.20:1, greater than 3.5:1, greater than 3.25%, or greater then crimped fibers are finer than crimped.
The ratio of CPI to DPF is an important measure that ensures the correct CPI is being imparted to a given DPF. It also maintains the necessary crimp frequency, tenacity and crimp frequency for the DPF. CPI:DPF ratios that are desirable include between 4:1 and 20:1, especially 5:1 or 14:1, as well as 7:1 or 12:1.
The crimp amplitude can vary when the fibers are crimped. It could be as low as 0.5 or 0.6 or 0.7 or 0.85 or 0.93 or 0.96 or 0.98 or 0.98 or 1.04 in each case. Alternately, the crimp strength of the fibers may be as high as 1.75 or 1.70 or 1.65 or 1.55, or at least 0.98 or at least 1.04, in each case mm.
“Additionally, final staple fibers might have a minimum crimp ratio of about 1:1. As used herein, ?crimp ratio? The ratio of the non-crimped length to the crimped length is called the “crimp ratio”. Some embodiments of the staple fibers can have a crimp ratio at least 1:1, at most about 1.1:1, and at most about 1.125:1, and at least 1.15:1, or at minimum 1.2:1.
Summary for “Molded articles made from a fiber-slurry”
“Recently, convenience foods such as fast food and casual dining have increased in popularity, which has led to a greater need for single-use packaging and containers. In the same way, consumers and manufacturers have become more conscious of the environmental impact of their products.
“There is a demand for non-persistent, environmentally friendly articles that can be used in many applications including food, beverage and packaging. The material would have desirable properties like strength, water resistance, durability, and environmental sustainability while in use. However, it would be quickly and without any environmental impact after disposal.
“In some embodiments of the invention, the contoured molded articles are formed from a fiber-slurry. The molded article includes a mixture of cellulose fibers as well as a cellulose ester.”
The present invention is a method for creating a contoured, molded article using a fiber slurry. The process involves: (a) making a fiber mixture consisting of cellulose fibers, staple fibers from cellulose ester, and at most one liquid;(b) contacting this fiber slurry with an a contoured molding mold; (c), forcing some of the liquid through the forming mould while retaining at minimum a portion the fibers on the contoured surfaces of the mold to form a contoured fibrous surface on the forming surface to allow for the formation of a liquid layer; (e) drying the contoured-formed article once it has been dry the wet-formed article to create the contoured mold article.
“In some embodiments of the invention, the use of fiber slurry to make a molded article is contemplated. The fiber slurry includes cellulose fibers and staple fibers that are cellulose ester.
“Composition containing cellulose fibers or synthetic cellulose fibers comprising of cellulose ester staple fibres is now available. The cellulose ester fibers must have one or more of the following characteristics: a denier per fiber (DPF) less than 3.0; a cut length less than 6 mm; a non-round form and/or crimped (referred to throughout as?Composition?). These Compositions can be found in any of the following process zones or steps. They also can be found in any vessel or pipe in a stock preparation or wet lay machine process. The Compositions may be present in feeds to, inside, or effluents of a hydropulper or any other blending vessel, refiner, a chest, a stuffbox, a hydrocyclone or a fan pump, in the pressure screen, on the wire and in the presses dryers sizing press, in the calender, sheets on rolls, in a broken vessel, in a calender or as consumer articles. The Compositions can also be found in wet-laid articles. These can also be prepared with the Compositions.
“The Compositions contain cellulose fibres and cellulose est fibers, at least a portion which are cellulose staple fibers
“Cellulose fibers” are those fibers that are not further chemically derivatized using functional groups. Cellulose fibers are made from virgin material or can be recycled.
“The CE staple fibers are synthetic fibers that are derivatives from cellulose obtained through a synthetic process. However, as used herein exclude the regeneratedcelluloses or other derivates cellulose-based such as rayon, viscose, and lyocell cellsulosic fibers.”
“A ?100% Cellulose Comparative composition? A composition in which 100% of the fiber component is cellulose fibers. It is also the same as a reference composition, including consistency, type of cellulose fiber, formulation ingredients and quantities as well as stock preparation conditions and conditions and refining conditions. If the reference is to either a sheet of wet-laid product, the 100% Cellulose Comparative Composition will also be a sheet- or wet-laid product. Alternatively, if the reference refers to a composition that contains both virgin and waste/recycle fibers, the 100% Cellulose Comparative Composition will also contain the same amount of virgin cellulose fibers to waste/recycle fibers.
“A ?cellulose fiber? “A?cellulose fiber” can be made from virgin or recycled fibers and can be fibrillated, non-fibrillated, or both.
“?Co-refining? “?Co-refining? Co-refined means that at most one cellulose fiber and one CE staple fiber have been refined together. Cellulose fibers and CE staple fibres in a feed stream to refiners are considered co-refined. A co-refined CE fiber refers to a cellulose fibre that has been refined in the presence a CE staple fibr. A co-refined CE fiber signifies that a CE staple fibre has been co-refined with a cellulosefiber.
“The ?consistency? “The consistency” is a measurement of the solids content in a liquid stream. It can be measured by drying a representative of the liquid stream and then dividing the weight from the oven dried solids to that of the representative sample.
“A ?machine direction? “A?machine direction? The direction in which the web moves on a machine that is wet laid. The?cross direction? The?cross direction? The direction that crosses or is perpendicular with the MD of the sheet or web.
“A ?non-woven web? A web made of fibers without the use of knitting or weaving operations.
“A ?Post-Addition? “A?Post-Addition? This is a mixture of fibrillated or refinedcellulose fibers and CE staple fibres. The CE staple fibers are only combined with the other cellulose materials after the cellulose has been refined. If the feed to refiners does not contain CE staple fibres, the CE staple fibers will be deemed not to have co-refined. The Post Addition Composition can be used as a comparison. However, the CE staple fibers do not occur during refinement and are only combined with cellulose fibres after the cellulose has been refined. The Post Addition Composition’s cellulose fibers are refined in the same conditions as the reference Composition. In other words, the consistency of cellulose fiber furnish that is fed to the refiner will be the same consistency as the reference Composition. After the cellulose fibres have been refined, the CE staple fibers are added into the refined cellulose furnish. The consistency of the blend will be adjusted to match the consistency of reference Composition. Post-Addition CE staple fibres are CE staple fibrs that have been added to cellulose after the cellulose has been refined.
“A ?thick stock? A stock with a minimum solids content (or stock consistency), of 2.0 wt. %.”
“A ?thin stock? A stock with a solids content (or stock consistency), less than 2.0 wt. %.”
“Virgin” is a term that refers to stock or fibers. “Virgin” refers to stock or fibers that are not being used for their intended use. However, the fibers must not have been inked or de-inked when they are contained in a web or other article.
“A ?wet laid non-woven product? A product weighing at least 50 wt. Fibers with a L/D greater than 300 have a minimum of 5%.
“Waste/recycle” is a term that refers to products that have been processed into fibers or stock. “Waste/recycle” refers to fibers and stock made from products that have been printed or used for their intended purpose.
“A ?wet laid process? A process where fibers are dispersed in liquid, such water, onto a wire, drying matt or filter. The liquid is then drained or removed to form the web. It is possible to distinguish a wet laid process from one that uses air-laid, carding, or needlepunch methods.
“A ?wet laid product? or ?wet laid web? A product that is made using a wet-laying process. It can be non-woven and also contain paper-like products with at least 50 wt. A minimum of 3% of fibers have a L/D of 300.
“The word ‘can? is equivalent to?may? “The word?can?? is equivalent to the word?may? is equivalent to?may? . . .?”
“Whenever a claim refers to a compositional characteristic that is quantified by a comparison between an inventive composition and a comparative (e.g. A 100% cellulose comparative or Post Addition composition is sufficient to satisfy the claimed feature for purposes of infringement.
“Raw Materials: Cellulose Fibers”
“Cellulose fibers are one of the components in the Composition. Cellulose fibers are made from cellulose. The unbranched polymer D-glucose (anhydroglucose), which is obtained from plants, is included in the term cellulose. Cellulose and cellulosic fibres contain at least one unbranched polymer of D-glucose. Optionally, they can also include hemicellulose or lignin. Each cellulose polymer chain associates to form thicker microfibrils, which in turn associate to form fibrils that are arranged into bundles. When viewed under a scanning electron microscope or light microscope, the bundles create fibers that can be seen as part of the plant cell walls.
“Hemicellulose” refers to a heterogeneous collection of low molecular weight carbohydrate monomers that are linked with cellulose in wood. Hemicelluloses are typically branched polymers in contrast to cellulose, which is a linear type of polymer. D-glucose and Dxylose are the principal simple sugars that can be combined to make hemicelluloses.
Lignin is an aromatic complex polymer that makes up about 20% to 40% wood, where it occurs as an inorganic polymer. There are three main types of lignins: softwood, coniferous (gymnosperm), hardwood and grass (monocotyledonous giosperm). Softwood lignins are often characterized as being derived from coniferyl alcohol or guaiacylpropane (4-hydroxy-3-methoxyphenylpropane) monomer. Hardwood lignins contain polymers of 3,5-dimethoxy-4-hydroxyphenylpropane monomers in addition to the guaiacylpropane monomers. The grass lignins contain polymers of both of these monomers, plus 4-hydroxyphenylpropane monomers. When isolated using similar methods, hardwood lignins can be more heterogeneous than softwood lignins.
“Representative sources for cellulose fibers include but aren’t limited to wood and non-wood plant sources such as cotton, cereal straws, flax and flax. You can get cellulose fibers from virgin or recycled cellulose fibers or any combination of both.
Table 1 below shows the typical fiber lengths of a variety pulped cellulosic fibres.
“Hardwood and non-wood fibers can be combined to create a unique article that has the desired strength, whiteness, writing surface, or other characteristics. Recovered fibers are ideally suited for applications such as paper, packaging and newsprint because of their mixed characteristics. Table 2 shows examples of softwoods and hardwoods from different sources and describes their characteristics.
TABLE 2 – Features Hardwood Trees Softwood treesnType of Oaks and poplarsnTree birches or eucalyptus are used for Finland, Norway, and papermaking. The Americas have Sweden. Softwoods (SBHK), which are used for strength, is found primarily in the southeastern region (NBSK) in Canada. Eucalyptus is Softwood for large bulk. It is mainly grown in Brazil. (SBSK is found in thenpapermaking. southeastern USA.\nType of Short Long\nfiber\nAverage 1 mm 3 mm\nlength of\nfibers\nFeatures Achieving bulk, smoothness, Providing additional strength.\nopacity Also suitable for writing and\nprinting\nTypical Writing papers, printing Shipping containers, grocery\nproducts papers, tissue papers bags, corrugated boxes”
Kraft softwood fiber is a low-yield fiber that is made from coniferous materials. It includes Northern and Southern softwood Kraft fibre, Douglas Fir Kraft fiber, and so on. Kraft softwood fibers have a lignin percentage of less than 5 % by weight. They also have a shorter length weighted fiber length than 2 mm and a longer arithmetic fiber length than 0.6mm. Kraft hardwood fiber is made from Eucalyptus hardwoods using the Kraft process. It generally has a lignin percentage of less than 5% by weight. Kraft hardwood fibers are typically shorter than Softwood fibers. They have a weighted average fiber length less than 1 2/3 inches and an arithmetic mean length less than 0.5 or 0.4 millimeters.
“Waste/recycle fibre can be used to provide cellulose fiber for the Composition or may be added to virgin fibers. Any suitable waste/recycle fibre can be used. However, waste/recycle fibr with low groundwood levels, such as office waste containing less than 15% or 10% by weight of lignin, may be useful. Newsprint waste may contain high amounts of lignin (e.g., more than 10 wt. % or 20-40 wt. % lignin.”
“In any of the above-described embodiments, cellulose fibers can either be fed to a Hydropulper as a pulp containing liquid or dried pulped material (e.g. As sheets or bales made from pulpedcellulose. The wet-laying process can be used for any method of obtaining pulp. A pulp is a mixture of water and plant-based cellulose fibers. It can be made by any one of many pulping methods that are familiar to those who have experience in the art, such as PGW, PGW, TMP or CTMP. As described further below. A source of cellulose is needed to make pulp. Wood sources are first debarked, then chipped and optionally pithed. To make pulp, the chipped wood can be subjected either to chemical or mechanical processing. A mechanically processed pulp is used in many wet-laid processes such as paper, tissue, and cardboard manufacturing. The refining and treatment of wood chips under atmospheric conditions, steam treatment or chemical treatment, is called mechanical pulp. The mechanical pulping process produces a mixture fibers and fragments of fibers, but does not remove the lignin. This results in a lower quality paper that is more prone to discoloring over time. Examples of suitable mechanical processes for obtaining pulp include the bleached chemical thermomechanical pulp (BCTMP) process, the pressure groundwood pulping process (PGW), thermomechanical pulp processes (TMP), chemithermomechanical pulp processes (CTMP) and alkaline peroxide mechanical pulp processes (APMP). PGW pulp uses all wood. It is suitable for newsprint production and other applications where high quality pulp can be obtained over a long life span. TMP pulps are stronger than PGW and can be used in newsprint. They also have applications in tissue and paperboard. CTMP pulps are a mixture of mechanical processing and chemical processes. The pulp is softened by adding sodium sulfite carbonate, hydroxide or hydrogen to it.
The pulp can then be further processed in a mill to remove any additional impurities by screening, washing and de-knotting.
A full chemical pulp process uses a combination of pressure, steam, and cooking liquor to dissolve lignin from the cellulose fibers. Chemical pulp papers are often called wood-free papers. This is because they don’t contain mechanical pulp lignin which can cause deterioration over time. To make white paper, the pulp can be bleached. Chemical pulps are easier to bleach than mechanical pulps, as the chemical processes remove most of the lignin from the cellulose source.
“The ability of pulp to reflect monochromatic light is a measure of its whiteness. This standard (usually magnesium oxide) is used to determine the whiteness. The Zeiss Elrephro reflectancemeter, which is a diffuse light source, is a common instrument. Unbleached Kraft pulp can be as low as 15% Elrephro units, while fully bleached sulfite pulps may test up to 94%.
Unbleached pulps have a wide range in brightness values. Chemical pulps produced by the sulfite process are brighter, at up to 65%. Semichemical pulps made with Kraft, soda, and semichemical processes can be quite dark.
The pulp can be bleached, regardless of whether it is chemically or mechanically processed. Chemical means include chlorine dioxide, oxygen and peracids as well as hydrogen and alkaline peroxide. It is preferred that oxygen be used in bleaching and that chlorine is avoided. Bleached pulps that have been treated without the use of elemental chlorine or hypochlorite is known as (ECF), Elemental Chlorine-Free. Mills can go to “TCF” or Totally Chlorine-Free for a more strict bleaching process.
“Table 3 contains a table that lists the different types of pulp.
“TABLE 3\nAbbre-\nviation Type Description\nMechanical Pulps\nRMP Refiner Mechanical Pulp Raw wood chips refined and dis-\ncharged at atmospheric pressure\nTMP Thermomechanical Pulp Steamed raw chips refined unpres-\nsured and again under no pressure.\nCMP Chemical Mechanical Chemically treated chips refined at\nPulp atmospheric pressure.\nCTMP ChemiThermoMechanical Steamed, chemically treated chips\nPulp refined under pressure and again\nunder no pressure\nFull Chemical Pulps\nSo Soda Pulp Chips cooked under pressure with\nstrong NaOH\nK Kraft Pulp Chips cooked with strong NaOH\nplus Na2S”
“Mechanical pulps are used in the production newsprint and magazines. Full chemical pulps can be used to make printing/writing paper and sanitary/household packaging material.
“Waste/recycled paper pulp can also used in Compositions to make wet-laid products. You can recycle paper/board made from chemically or mechanically manufactured pulp. Mixing the waste paper/board with water can break the hydrogen bonds and separate the fibers. Although recycled papers can be made with 100% recycled materials, or mixed with virgin pulp, they are generally not as strong and bright as papers made from the former. For strength and quality, most paper made from recycled paper/recycled paper has a small amount of virgin fiber.
“There are two types of waste/recycled fibre, and any one or both can be used in the Composition as a source for cellulose fiber:
Mill broken or internal mill waste includes any substandard or grade-change papers made in the paper mill. These materials are then re-pulped into paper by the manufacturing system. This out-of-specation paper cannot be sold and therefore is not often classified as genuine recycled fiber. However, most paper mills have been recycling their waste fiber for years, long before recycling was common. This category of waste is called “broke” for clarity. pulp is not considered waste/recyclepaper or waste/recyclepulp as it is used in this description.
“In sum, the pulp sources containing the cellulosic fiber to make the Compositions and wet laid products are not limited, and may comprise a blend of conventional fibers (whether derived from virgin pulp or waste/recycle sources) and high coarseness lignin-rich tubular fibers, such as bleached chemical thermomechanical pulp (BCTMP), thermomechanical pulp (TMP), chemithermomechanical pulp (CTMP) alkaline peroxide mechanical pulp (APMP) and the groundwood pulp (GWD), in each case bleached or unbleached, deinked, and can be processed chemically by the Kraft method to make Kraft pulps (both sulfate and sulfite) and bleached Kraft pulps. The recycling stage may bleach recycled pulps. To produce a bleached pulp material, any of the pulps mentioned above that have not been previously bleached may be bleached in the manner described herein.
The Composition can be used as a furnish or can be used in any other composition before refining. It can contain virgin nonfibrillated cellulosic fibers, refined cellulose fibres, and can also contain co-refined cells (which may include broken), and can also include a mixture of virgin and recycled non-fibrillated cellulosic fibers. One or more of the above-mentioned embodiments reveals that cellulosic fibre is obtained from wood. This can be softwood or hardwood.
“In any one of the above embodiments, the Composition includes pulpedcellulose fibers or is made by adding pulpedcellulose fibers to the CE staple fibres.
“In any one of the above-mentioned embodiments, pulpedcellulose fibers are mixed with CE staple fibers or are present within the Composition or in the wet laid products that contain the Composition or are obtained from the Composition in an quantity of at least 60 wt. % or more than 70 wt. % or less than 71 wt. % or at least 72 Wt. % or at least 75 Wt. %, or at most 80 wt. %, or at most 90 wt. % or at least 95 Wt. % or at least 98 Wt. %, or at most 99 wt. % or 100 wt. % based on the total weight of all cellulose fibres (not including CE staples fibers) in the Composition/wet laid product. 100 wt. %, there are no unpulped fibers of cellulose.”
“In at least 60 wt., wood pulp can be found in the Composition in one or more of the above-mentioned embodiments. % or more than 70 wt. % or 75 wt. %, or at most 80 wt. %, or at most 90 wt. % or at least 95 Wt. % or at least 98 Wt. %, or at most 99 wt. %, or at least 99 wt. % in each case is based on the total weight of all cellulose fibres (not including CE staples fibers) in the Composition/wet laid product. Non-pulped and nonwood pulped can be used for the remaining cellulose fibers. Desirably, these cellulose fibers are pulped from non-wood plant-based resources.
“In any one of the above-mentioned embodiments, nonwood cellulose fibers may be present in the composition or wet laid products containing the composition in a quantity of less than 95 wt. % or less than 80 wt. % or not more that 60 wt. % or not more that 50 wt. %, or not more that 40 wt. %, or not more that 30 wt. %, or not more that 25 wt. %, or not more that 20 wt. %, or not more that 15 wt. %, or not more that 10 wt. % in each case, based on the total weight of all cellulose fibres in the Composition/wet laid product. The remaining cellulose fibers are wood-sourced cellulose fibres or, if desired, pulped wood-sourced cellulose fibrs. This embodiment, or any other embodiment, can have a minimum of 30 wt. % or at most 40 wt. % or at least 50 Wt. % or at least 60 Wt. %, or at most 70 wt. %, or at most 80 wt. %, or at most 90 wt. % or at least 95 Wt. % based on the total weight of all cellulose fibres in the Composition.
“In any embodiment, or in any of the embodiments, the Composition or the effluent from an refiner or the Composition or wet laid products that contain or are obtained from the Composition must not exceed 5 wt. % or not more that 3 wt. % or less than 1 wt. % or less than 0.5 wt. % or 0.25 wt. % or less than 0.01 wt. % or 0.01 wt. % or less than 0.01 wt. % or less than 0.0001 wt. Based on the Composition’s weight, % of fiber bundles.
“In any embodiment, or in any of the above embodiments, the Composition includes virgin non-fibrillated and/or co-refined virgincellulose fibers in an amount of at minimum 25 wt. % or at least 50wt. % or at least 50 wt. % or at least 60 Wt. %, or at most 70 wt. %, or at most 80 wt. %, or at most 90 wt. % or at least 95 Wt. % or at least 95 wt. %, or at least 98 wt. Based on the total weight of all cellulose fibres in the composition, %.
“In another embodiment, or in any other embodiment, the Composition contains either waste/recycled cellulose fibers or co-refined cellulose fibers in an amount of at minimum 25 wt. % or at least 50 Wt. % or at least 50 wt. % or at least 60 Wt. %, or at most 70 wt. %, or at most 80 wt. %, or at most 90 wt. % or at least 95 Wt. %, or at most 98 wt. % or 100 wt. Based on the total weight of all cellulose fibres in the composition.
“The Composition may also contain a mixture of virgin cellulose fibers as well as waste/recycled cellulose fibers.
“The Composition, as mentioned above, contains at least one cellulose fiber. It is desirable that the Composition contains at least one cellulose fiber in any embodiment.
A virgin non-fibrillated cellulose fiber is one that hasn’t been subjected any refining operations at all or that has not been beat or refined after the preparation of a pulp product. It is either ready for use or has been received to a wet lay process facility (e.g. Ready to be used as a feed for a stock preparation area in a wet-laid process. The pulp may not have the required amount of fibrillation to the cellulose fibers during the pulp preparation stage. However, non-fibrillated fibers are fibers that have not been subjected either to beating or refining. Many times, the amount of fibrillation that was imparted during pulp preparation is not sufficient to make a wet-laid product suitable for use. The process of making pulp from wood, or other plants as described in the above description is not included in the wet laid process. TMP, TMP CTMP, APMP and GWD are all examples of the wet laid process. Some of these methods can cause minor fibrillation of the cellulose. However, this is not enough to produce useful wet-laid products. As discussed below, compositions that contain virgin non-fibrillatedcellulose can be useful feeds for a refinery operation.
“Virgin fibrillatedcellulose fibers” are cellulose fibres that have been pulped and are then subject to a refinement operation to fibrillate them.
“Co-refined Cellulose Fibers” are those in which the cellulose fibres have been fibrillated under the control of a refiner with the addition of CE staple fibers. Co-refined fibers of cellulose can be virgin, recycled, or a combination of both. The wet-laid products that contain or are obtained from Post Addition Compositions have been shown to be inferior in certain respects. We will discuss this further below.
“The Compositions may use either fibrillated waste/recycled cellulose fibers or not. However, in most cases the fibers were already fibrillated when they were made as virgin products.”
“Any reference to a composition includes cellulose that is present in any of the following: a) or b) before refining and b), c), and/or (d) after refining.
“Raw Materials”: Cellulose Ester Fibres
“The cellulose ester staple fibre (?CE staple fiber)” “The cellulose ester staple fiber (?CE staple fiber) is a type of CE polymer. The suitable CE polymers are cellulose derivatized using a reactive compound to produce at least one ester at the hydroxyl site of the cellulose backbone. These include cellulose, cellulose diacetate and cellulose triacetate. While cellulose acetate is the focus of this article, it can also be used as a reference. It should be noted that the fibers can be made from any combination of the cellulose acid esters and mixed esters. U.S. Pat. describes a variety of cellulose esters. Nos. Nos. Regenerated cellulose (e.g. rayon, viscose or lyocell), and the fibers therefrom are not considered CE polymers or CE staple fibres as used herein.
“The CE staple fibers in one or more of the above embodiments are desirable virgin CE staple fibres. Cellulose ester fibers derived from other sources can be contaminated with additives and printing material. For example, cellulose ester fibers from cigarette filters can be contaminated with plasticizers like triacetin. These plasticizers, as we will see, can cause agglomeration or flocculation of resulting webs. If cellulose ester fibers are printed with material, it is undesirable.
“In any one of the above embodiments, the CE staple fibres are not to be refined or non-fibrillated after they have been combined with cellulose fibers or before being fed to a refiner. The Composition may contain both cellulose fibers as well as non-fibrillated CE staple fibers. This means that the CE staple fibres have not been refined to fibrillate them. The process of cutting filaments for the CE staple fibres is not considered to be a refining or fibrillating process. The CE staple fibres are not separated from cellulose fibers. However, the mixture will be subject to refining or the addition of non-fibrillated CE fibers after the cellulose fibrils have been refined. In each case, the invention will produce one or more effects. Non-fibrillated CE staple fibres are those that contain less than three fibrils/staple, not more then two fibrils/staple, not more or less than one fibril/staple, not more or less than 0.5 fibril/staple, not more or more often than 0.1 fibril/staple, not more or more frequently than 0.05 fibril/staple, not more or more commonly than 0.01 fibril/staple, not more or more regularly than 0.001 fibril/staple, not more, not than 0.0001 fibril/staple, not aple fiber or, not, not, not, not 0.01 fibril/staple, not, not, not, not, not, not, not, not, not, not, not over, not, not, not, not, not, not, not, not, not more or, not, not, but not, not more, not than, not more, not than, not mehr failing to be below 0.0001 fibril/staple or more or more or more or more or more or more or more or more or more or more or more or more or more or more or more or preferably besides an averagedo 5.0001 fibril/staple or more than 0.0001 fibril/staple or more than a non-fi a averaging get Koch apparently prioritize privat A non-refined CE staple fibre is also available. This means that it has not been refined. A composition can contain CE staple fibers that are either nonfibrillated or non-refined. The following examples show that compositions can be made at any stage prior to refining. They may include CE staple fibers that are either non-fibrillated or not-refined or both nonfibrillated or nonrefined. The combination of CE staple fibres and cellulose esters can be refined to make the CE staples non-fibrillated. However, they are no longer considered to be non-refined.
“The cellulose ester may have a degree or substitution that is not restricted, but it is desirable to have a range from 1.8-2.9. The term “degree of substitution” is used herein. Alternatively,?degree of substitution? The average number of acyl substitutes per anhydroglucose-ring of the cellulosepolymer is 3.0. The degree of substitution for cellulose esters used in the formation of fibers may be as low as 1.8 or 1.95 or 2.0 or 2.05, or 2.2 or 2.3 or 2.8 or 2.9 or less than 2.7 or 2.8 or more that 2.7 or 2.8 or more then 2.8 or more about 2.9 or more or more. Or not more or less than 2.55, or 2.55, or 2.55, or 2.55, or 2.5 or 2.5 or 2.5 or 2.5 or 2.5 or 2.4 or 2.35. At least 90 or 91 or 93 or 95 or 98 or not more than 2.9 or 2.8 or not more than 2.7 or not more that 2.6 or not more than 2.55, or not less then 2.55, or 2.45, or 2.25, is desirable. Acetyl groups can be found in at least 1, 5, 10, 15, 25, 30, 35, 45, 50 or 55 percent, and/or not more that 99 percent, or more than 90 percent, or more than 85, not more then 80, not more 75, not more over 70%, or less than 99 percent of total acyl substitutes. It is desirable to have a greater than 90 percent weight percentage, or greater 95%, or higher than 98%, more than 99.9%, or up to 100 wt. Acetyl substitutes (C2) make up 5% of total acyl substitutions. The cellulose ester cannot contain acyl substitutes with a carbon number greater than 2.
“In any embodiment, or any of these embodiments, the DS for the cellulose esterpolymer is not greater than 2.5 or less than 2.45. The best CE staple fibers are both industrially and home-compostable when they have a DS not exceeding 2.5. Also, CE staple fibers made from cellulose ester polymers with a DS below 2.5 are soil biodegradable according to the ISO 17566 method.
“The cellulose ester may have a weight-average molecular weight (Mw) of not more than 90,000, measured using gel permeation chromatography with N-methyl-2-pyrrolidone (NMP) as the solvent. The cellulose ester might have a molecular mass of 10,000 in some cases. This is measured using gel permeation chromatography with N-methyl-2-pyrrolidone (NMP) as the solvent.
“Desirably the CE staple fibers can be mono-component fibers. This means that there are no distinct phases such as islands, domains or sheaths made of other polymers in the fiber. A mono-component fiber may be made entirely of CE polymers or can contain a mixture of CE polymers and another polymer. At least 60% of the CE staple fibres’ composition must be CE polymers. These percentages are not inclusive of spin or cutting finishes that were applied to the filaments after they have been spun, or any other additives with a number average molecular mass less than 500.
“The cellulose ester can be made by any method. However, the CE staple fibers should be obtained from filaments that have been spun by solvent. This is different from precipitation or emulsion flashing. To make a “solvent dope”, the cellulose ester flake can be dissolved in solvents such as acetone and methyl ethyl ketones. This can be filtered and passed through a spinnerette in order to make continuous cellulose ester filaments. Sometimes, it can reach 3 wt. %, up to 2wt%, up to 1weight percent, up to 0.5wt. % or up to 0.25 Wt. % or as low as 0.1 wt. Based on the weight of dope, a % of titanium dioxide or another delusterant can be added to dope before filtration. Depending on the desired properties of the fibers and their ultimate end use, the amount of titanium dioxide added may vary from 1% to 0.1 wt. Continuous cellulose ester filaments can then be cut to the desired length. This results in CE staple fibers with low cut length variability and consistent L/D ratios. They are also available as dry fibers. The precipitation-based cellulose ester forms have a low length consistency, are random in shape, have wide DPF distributions, have wide L/D distributions, can’t be crimped and are not supplied wet.
“In some cases, other additives to the cellulose ester may be added to the solvent dope/flake used to make CE staple fibers. These additives may include, but not be limited to: plasticizers and antioxidants, thermal stabilizers or acid scavengers. Inorganics, pigments and colorants. The CE staple fibers described herein may include at most 90 or 90.5 or 91 or 92.5 or 93 or 95 or 94.5 or 96 or 96.5 or 97 or 98 or 96.5 or 97 or 98 or 99.5 or 97 or 97 or 98 or 99.5 or 97 or 98 or 99.5 or 99.9 or 99.995, or 99.999 percent of cellulose ester based on the fiber’s total weight. Fibers can contain or include no more that 10, or less than 90.5, not greater than 8 or more, not less than 7 or more, not higher than 6 or more, not higher than 6.5, not greater than 7 or more, not over 6.5, not above 7 or more, not at all 95, not at least 93.5, not at least 92.5, not at least 93, not just 94, not only 95, not at minimum 95.5, not below 96, not above 96.5, not beyond 97, not cellulose ester, not cellulose esters, but not cellulose ester fibre, and not cellulose, cellulose ester, not cellulose, not cellulose, not cellulose, cellulose ester, not cellulose, not cellulose, not cellulose, not cellulose, not cellulose, not cellulose, not cellulose, not cellulose, cellulose, not cellulose, not cellulose, not cellulose, not cellulose, not cellulose, not cellulose, not, not cellulose, cellulose ester, cellulose ester, cellulose ester, cellulose ester fiber, cellulose, not cellulose, cellulose, not cellulose, cellulose, cellulose, cellulose ester, cellulose, cellulose, cellulose, cellulose, cellulose, cellulose ester, cellulose, cellulose, cellulose ester, cellulose ester, cellulose ester, cellulose ester, cellulose ester cellulose ester cellulose ester cellulose ester cellulose ester cellulose cellulose ester cellulose cellulose, cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose res cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose s cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose cellulose, cellulose cellulose sa cellulose cellulose ester cellulose cellulose cellulose cellulose cellulose ester cellulose cellulose sa cellulose cellulose s s cellulose s s s s sta cellulose s spy sa s sp
The solvent can be extruded through multiple holes at the spinnerette to form continuous cellulose ester fibers. The spinnerette allows filaments to be drawn into bundles of hundreds, or even thousands, of individual filaments. These bundles or bands may contain at most 100 filaments or 150 filaments or at the very least 200 or 250 or 350 or 350 or 400 or more than 1000 or 900 or 800 or 750 fibers or not over 700. You can operate the spinnerette at any speed that produces filaments. These filaments are then assembled into bundles of desired size and shape.
Multiple bundles can be assembled to form a filament band, such as a crimped or uncrimped band. A filament band can be any size. In some embodiments, it may have a total denier of at most 10,000 or 15,000 or 30,000 or at minimum 45,000 or at most 40,000 or at best 75,000 or at worst 50,000 or at lowest 150,000 or at the least 200,000 or at minimum 250,000 or at least 300,000. Alternately, and in addition, the total denier for the tow band cannot exceed about 5,000,000 or less than 4,500,000 or less than 3,000,000 or more that 3,000,000 or more then 2,000,000 or more or more or more or more or more or more or more or more or more or more or more or more or more or more or more or at least 100,000 or at least 150,000 or at most 250,000 or at least 300,000.
“We found that any one of the CE staple fiber cut lengths, shapes, denier per fiber, and crimp can influence one or more properties wet laid products containing or obtaining by the Compositions. These include surface smoothness and water drainage rates, absorbency and stiffness even with smaller pore sizes, nonwoven densities, light-weighting and rewettability, softness and tensile strengths. Below are detailed descriptions of each of the CE staple fiber characteristics.
The individual filaments that are spun in a generally longitudinally aligned fashion and form the tow band are of a specific size. Linear denier per filament is the weight in g of 9000m fiber length, or DPF of CE filaments and corresponding CE staple fibers. It should be within a range between 0.5 and 3. There are many methods for measuring the filaments. These include ASTM 1577-07 using FAVIMAT vibroscope procedure, if the filaments can be obtained from which staple fibers were cut, or width analysis using any optical microscopy, Metso, or other convenient optical microscopy.
The DPF can also be used to determine the maximum fiber width. The fiber’s maximum width is determined by its longest outermost dimension. If the fiber is not round, it is possible to measure the longest outer diameter by spinning the fiber. The table 4 shows a handy correlation between DPF and maximum widths (or outer dimensions) of fibers. This is true regardless of their shape or multi-lobal configurations.
“TABLE 4nApproximatenDPF Width (microns)n1.6 22,n2.0 25,n2.4 28,n2.8 30,n3.2 32n3.634n4.0 36”
“Desirably the DPF ranges of the filaments and of the CE staple fibres are 1.0-2.8 or 1.0-2.5 or or 1.0-2.2 or 1.0-1.2.1 or 1.0-2.1 or more desirable from 1.0-2.0 or 1.0-2.999 or 1.1-1.9 or 1.1-1.1.9 or 1.1-1.8. Handsheets made from the Compositions with CE staple fibers with a DPF below 3 have higher air permeability than those made with fibers with 3 DPF or less.
“In any other embodiment, or in any of the above embodiments, the maximum fiber width is less than 31 microns or not over 30 microns or more than 27 microns or more than 26 microns or more than 25 microns or more than 25 microns or more than 25 microns or more that 24.5 microns or more than 24 microns. One embodiment, or any of the above mentioned embodiments, has a minimum width or diameter of fibers that is greater than 1 micron (1000 nm).
“In any one embodiment, or any of these embodiments, at minimum 70% or at most 80%, or 85%, or more than 90%, or a minimum of 95%, or a minimum of 97% of the CE-styl fibers have a DPF that is within +/-20% of any of the above mentioned DPF. Alternately, at minimum 70% or 80% or at most 95% or 97%, or a minimum of 95% or 97%, the CE staple fibres have a DPF that is within +/-15% of any of the above mentioned DPFs; or at the least 70% or 80% or at the least 85% or at the least 90%, or a minimum of 95% or at the least 97%, the CE staple fibrs have a DPF that is within +/-10% of any of the DPF. At least 85% or 90% or at most 95% or at minimum 97% of CE staple fibers has a DPF of within +/-15% or within +/-10% of any of the above mentioned DPF.
“In any one of the above embodiments, the DPF may have a narrow distribution span that meets the following formula:
“d ? ? 90 – d? ? 10 d ? 50 * 100 ? S”
“Where d is calculated based on the median DPF. d90 is where 90% of fibers have DPFs less than target DPF. d10 is where 10% of fibers has DPFs less than target DPF. d50 is where 50% of fibers have DPFs less than target DPF. Lastly, S is 40% or 35% or 30% or 25% or 20% or 15% or 10% or 7%.
“The spinnerette’s individual cellulose ester filaments and the CE staple fibres may have any transverse cross-sectional form. Examples of cross-sectional shapes are, but not limited to, the round or non-round (non-round). Non-round shapes include Y shapes or other multi-lobal forms such as I-shaped (dog bone), closed C shapes, X-shaped and crenulated. A cellulose ester filament or CE staple fiber may have a multi-lobal cross sectional shape. It could have 3, 4, 5, 6, or more lobes. The filaments can be symmetric along one, more, two, more, three, or more or four or more of the axes. In other cases, they may be asymmetrical. The term “cross-section” is used herein. The term “cross-section” generally refers to the transverse length of the filament, measured in a direction that is perpendicular with the direction of filament elongation. Quantitative Image Analysis can be used to measure the cross-section of the filament. Staple fibers will be similar in cross-section to the filaments they were formed from, but without deforming them mechanically.
“In any one of the above embodiments, desirable, the shape and size of the CE staple fibre is:
Round-shaped CE staple fibers are known to reduce the air permeability of wet-laid products. A round-shaped fiber, such as a cellulose composite, can be used to achieve a minimum density of 0.450 g/cc. This will significantly improve water permeability. Shape factor less than 1.25 or made from filaments solvent spun through circular holes or targeted as round.
“In any one embodiment, or in any of these embodiments, at minimum 70% or at most 80%, or 85%, and at least 90% or at the least 95% or at the least 97% or at the least 99.9% of the CE staple fibres have the specified shape.”
After multiple bundles have been assembled into a filament yarn, it can be passed through a Crimping Zone where a pattern wavelike shape may be imparted at least to a portion or substantially to all of the individual filaments. The filaments may not need to be crimped in some cases. In these cases, the uncrimped filaments can be passed from the spinnerette directly to a drying area. The crimping area must contain at least one crimping device that can mechanically crimp the filament yarn. The crimping of filament yarns is not done by chemical or thermal means (e.g. steam, hot water baths or chemical coatings), but rather mechanically using a suitable Crimper. A?stuffing container? is one example of a suitable mechanical crimper. Or a?stutterbox? A crimper that uses a number of rollers to create friction. This causes fibers to buckle and forms crimps. You may also find other types of crimpers suitable. U.S. Pat. describes some examples of equipment that can impart crimp to filament yarns. Nos. Nos. “In some cases, the crimping may be done at a speed of 50 m/min (75. 100. 125. 150. 175, 200. 225. 250. m/min and/or not more that 750 m/min (475.450.425; 425.400, 400, 375. 350, 325 or 300 m/min).
“The average effective length of the crimped CE staple fibers is 85 percent in one embodiment and any other embodiments. The effective length is the distance between two points on a fiber. While the actual length is the fiber’s length end-to-end, if it were straightened perfectly, the actual length is the fiber’s maximum dimension. The fiber’s effective length will be the same length as its actual length if it is straight. If a fiber is straight, its effective length is equal to its actual length. The actual length is the length of the fiber from end-to-end if it was perfectly straightened. The average effective length of crimped fibers in one embodiment, or any of the embodiments herein, is not greater than 80.
Low DPF CE staple fibers are more susceptible to breaking when they are cut from the filaments or further processed than the normal frequency of Crimps imparted by higher denier fibers commonly used in cigarette filter. Crimping can be used to improve cohesion and entanglement of the CE staple fiber with cellulosic and other fibers. Due to the low DPF fibers, it is important to reduce fiber breakage during cutting to staple, when they are further processed, or when they are combined with cellulosic fibres. Crimping also helps to maintain a high level of retained tenacity. The term “retained tenacity” is used herein. The ratio of the tenacity a crimped filament or staple fiber to the tenacity a similar but uncrimped filament, expressed in percent. A crimped fiber with a tenacity (g/denier), of 1.3 grams would have an 87 percent retained tenacity compared to a fiber that has a similar but uncrimped tenacity (1.5 g/denier).
“In any one of the above embodiments, the crimped cellulose ester filaments can retain tenacity of at most about 40% or at minimum 50% or at the least 60% or at the least 70% or at the least 75% or at the least 75% or at the least 80% or at the least 85% or at the least 90% or at the least 95%.”
“Crimping can be done such that continuous filaments from CE staple fibers and/or CE staple fibers have a minimum crimp frequency of at most 5, 7, 10, 12, 13, 15, or 17, or up until 30, or 27 or 25, or 23, or 20, or 20 or more crimps per in (CPI) according to ASTM D3937-12. A higher than 30 CPI can lead to excessive breakage when cutting filaments to staple at small cut lengths. This also reduces their retained strength. A crimp will occur when the CE staple fibers are cut at shorter lengths than 5 CPI. The average CPI of the filaments used in making CE staple fibers should be between 7 and 30 CPI or 10-30 CPI or 10-25 CPI or 10-25 CPI or 10-25 CPI or 10-25 CPI or 10-20 CPI or 12-20 CPI or 12-25 CPI or 12-24 CPI or 12-24 CPI or 12-25 CPI or 12-24 CPI or 12-20 CPI or 12-20 CPI or 15-30 CPI or 15-27 CPI or 15-27 CPI or 15-25 CPI or 15 or 15 or 15 or 23 CPI or 15 or 20 CPI or 15 or to 23 CPI or 15 or 20 CPI or 15 or 20 CPI or 15 or 20 CPI or 15 or 20 CPI or 15 or 20 CPI or 15 or to 23 CPI or 15 or 20 CPI or 15 or 20 CPI or 15 crimp to 23 CPI or 15 or 20 CPI or to 20 CPI or to 20 CPI or to 20 CPI or 15 or 23 CPI or 15 or 20 CPI or 20 CPI or 23 CPI or 15 or 23 CPI or 20 CPI
“In any one of the above-mentioned embodiments, the ratio crimp frequency CPI/DPF can be greater or less than 2.75:1, 2.80:1, 2.90:1, 2.95:1, 2.95:1, 2.95:1, 2.95:1, 2.95:1, 2.95:1, 3.05:1, 3.05:1, 3.20:1, 3.20:1, 3.15:1, 3.20:1, 3.15:1, 3.20:1, 3.20:1, 3.20:1, 3.25:1, 3.40:1, greater that 3.40:1, greater then 3.45:1, greater or 3.45:1 or more than 1.45:1 or 3.45:1 or 3.45:1 or higher than 3.45 or 3.45:1 or 3.45:1 or 3.45:1 or 3.45:1 or 3.45:1 or 3.45:1 or 3.45:1. This ratio can be higher in some cases. For example, it may be greater than 4:1 or greater that 5:1 or greater that 6:1, or more than 2.90:1, or more than 2.95:1, or more than 3.05:1, or less than 3.20:1, or less than 3.15:1, greater than 3.25:1, greater than 3.15:1, greater than 3.00:1, greater than 3,05:1, greater than 3,05:1, greater than 3.20:1, greater than 3.5:1, greater than 3.25%, or greater then crimped fibers are finer than crimped.
The ratio of CPI to DPF is an important measure that ensures the correct CPI is being imparted to a given DPF. It also maintains the necessary crimp frequency, tenacity and crimp frequency for the DPF. CPI:DPF ratios that are desirable include between 4:1 and 20:1, especially 5:1 or 14:1, as well as 7:1 or 12:1.
The crimp amplitude can vary when the fibers are crimped. It could be as low as 0.5 or 0.6 or 0.7 or 0.85 or 0.93 or 0.96 or 0.98 or 0.98 or 1.04 in each case. Alternately, the crimp strength of the fibers may be as high as 1.75 or 1.70 or 1.65 or 1.55, or at least 0.98 or at least 1.04, in each case mm.
“Additionally, final staple fibers might have a minimum crimp ratio of about 1:1. As used herein, ?crimp ratio? The ratio of the non-crimped length to the crimped length is called the “crimp ratio”. Some embodiments of the staple fibers can have a crimp ratio at least 1:1, at most about 1.1:1, and at most about 1.125:1, and at least 1.15:1, or at minimum 1.2:1.
Click here to view the patent on Google Patents.