3D Printing – Nathan Christopher Maier
Abstract for “Cartridge feeder for additive manufacturing”
“A dispenser for additive materials manufacturing that contains a sealed cartridge containing sterile material to dispense. The cartridge can be removed from the support housing, which is mobile during the deposition of additive materials. The nozzle is attached to a heated plenum beneath the cartridge and is placed into a sealed variable volume container supporting the article’s fabrication on a movable table.
Background for “Cartridge feeder for additive manufacturing”
Due to the increasing popularity of additive manufacturing and technological advances in the field, it is essential to create an efficient dispensing system to manufacture medical devices, electronic components, food, chemicals, and other items. Individuals, doctors, and manufacturing professionals will increasingly use 3D printing systems. This means that there will be an increased demand for different types of 3D printers and tissue. Material dispensers can be quickly and easily exchanged to enable printing of various materials. A Jan. 27, 2015 New York Times article entitled “The Operation Before The Operation?” p. 06 describes the need for anatomical models to aid medicine and the possibility of using 3D printed models.
“The need to make anatomical models as well as actual body parts using additive manufacturing was recognized many years ago. In an article entitled “Rapid prototyping techniques to anatomical modeling and medicine?”, the state of this field was summarized some years ago. by M. McGurk et al. Ann. R. Coll. Surg. Engl. Engl. The creation of models was done by spraying liquid through the ink jet printer nozzles onto a layer precursor powder. This creates a thin, solid slice. Each successive slice was printed until the object reached a ‘green-state. It was then sintered in a furnace. The resultant object was then treated to create a part with full density.
“In recent years, 3D printing large objects has become easier thanks to the advancement of software for computer-controlled robotic XY motion systems used by the semiconductor and optics industry. SolidWorks, AutoCad 360 and similar programs make layering 3D objects easy and cost-effective.
For 3D printing larger objects, the print nozzles must be directed in the XY plane. This can be done by either placing the object on an XY table, where motion is provided below nozzles, or by mounting rails above nozzles to allow for XY motion directed above nozzles. U.S. Pat. demonstrates an XY table that allows motion below the nozzles. No. 5,760,500 to T. Kondo et al. linear actuators or stepper motors provide independent movement to a table above the X-Y plane. U.S. Patent. Describes highly accurate stepper motors that can be used for this purpose. No. 7,518,270 to R. Badgerow & T. Lin. U.S. Pat. describes a 3-D printer with overhead control for nozzles. No. 5,740,051 to R. Sanders et al.”
“In both motion situations, the nozzles move in X-Y relative to the object printed and also move up and down in the Z plane. They start at a lower level and work their way upwards. The first layer, or lamella, is printed at a low elevation. Next, the next layer is printed. Two nozzles may be used. One nozzle is used to extrude or spray a manufacturing material such as polymers, while the second sprays a support fluid. This fluid can be viscous or soft. A support fluid could be an ultra violet light-cured resin, which can be sprayed with ink jet. The faster drying support fluid dissolves when the manufacturing material becomes hardened.
It is well-known that filaments can be used as a source of material for additive manufacturing. In published application 2015/0037446, the authors describe how a gear is used to pull filamentary material into an extruder head. This gear drive is similar in design to U.S. Pat. No. No. 5,816,466 is where consumable welding wire is advanced from a reel by a gear drive mechanism and consumed during the welding process.”
Many medical professionals and researchers are currently looking at additive manufacturing through 3D printing as the future for custom manufacturing. This includes everything from medical devices to biological organs. The flexibility of additive manufacturing allows for the production of diverse items at a lower cost and faster than other manufacturing methods. 3D printing is used to create articles using patient-specific or patient-derived bone, and synthetic tissue and stem cell. In addition to contamination by airborne particles, dust and moisture, additive manufacturing presents a problem. Publication No. Publication No. 2015/0217514, Aug. 6, 2015. The invention was designed to create a system that dispenses thermoplastic and biological materials, which can be used in 3D printing equipment. It is free from dust, airborne particles, and moisture.
“The above object was achieved using a dispenser for additive manufacture that includes a sealed additive material dispensing unit and a filamentary material advancement means. The heating element melts thermoplastic material from filaments and forces the melted material into the nozzle.
“Another embodiment provides a sealed cartridge for inkjet printing of a commercially-available type with a nozzle that directs ink droplets towards a desired area. Both embodiments have the nozzle connected in sealed fashion to the material supply unit. The nozzle is placed in a sealed variable volume material chamber. In this chamber, the nozzle can be vertically moved relative to an XY stage. This enclosure allows for additive material deposit by superposed layers. The dispensing unit as well as the deposition chamber are protected against dust, airborne particles, and moisture during manufacturing. Two nozzles can be ganged side-by-side to print a larger stripe in the XY plane. The spacing of the nozzles should be such that the material ejected by the nozzles forms one solid stripe with no material overlap.”
One nozzle can extrude or spray a material, while the second can be used to spray support material. There are many other nozzle combinations that can be used for additive manufacturing with this technology. For example, two nozzles could dispense dissimilar thermoplastic filaments, while the third would spray a chemical binder. One nozzle sprays a thermoplastic polyjet material, while another nozzle deposits or extrudes bone paste. A third nozzle sprays a bone binder.
Material sprayed or extruded by the nozzles may be a filament pulled out of an enclosed reel or a fluid contained in a sealed container. The first situation is where a filament is pulled out of a sealed container and enclosed in a protective sheath. This sheath is then joined to a movable house. The housing houses a drive motor, a removable cartridge and a drive mechanism that allows the filament to be advanced with the power of the drive motor. The cartridge houses a conduit that holds filamentary material and is controlled by the drive gear. Any thermoplastic or meltable material that can flow after heating can be used as the filamentary material. Bio-materials include filamentary bone, joint substitutes and cellular materials. The housing has a fan that blows air into it to cool the filamentary material and the conduit. The heated part of the cartridge or the cartridge below heats the conduit and starts melting the filamentary materials. Material flows into the nozzle below this heated plenum, where it exits through a bottom aperture onto the deposition layer.
The nozzle must have a length that has a heat gradient greater than the heat gradient in a conduit to allow for one-way flow. A copper nozzle with a shorter length will have a higher heat gradient than a semiinsulative conduit of the same length. This means that heat will flow more to the pipe with a steeper heat slope, which is the nozzle.
“In the case fluid print material, a sealed container communicates fluid to an outlet, or nozzle, as in inkjet printers without the use of a drive gear, heated plenum, or drive gear. To allow fluid to flow and harden after dispensing, the fluid material’s viscosity must be controlled.
The advantage of the removable cartridge’s ability to be replaced or removed after using one material is in favor of another material or for cleaning or sterilization. Different print materials can be used on the same vertical motion stage to enable additive manufacturing without being exposed to dust, airborne particles, or moisture.
The present invention allows additive manufacturing in a sterile environment. It provides a sterile major, expandable chamber for volumetric expansion that allows XY deposition in a sequence to form an object. The sealed entry to the sterile main chamber allows for one or two nozzles to be inserted into the sterile chamber’s major expandable wall chamber. This chamber is used for 3D deposition of objects and a motion in Z for the nozzle or nozzles.
“DESCRIPTION DU DRAWINGS”
“FIG. “FIG.
“FIG. 2. This is a plan view showing a thermoplastic cartridge and dispenser being inserted in a closed 3D printing environment.
“FIG. “FIG.
“FIG. “FIG.
“FIG. FIG. 5. An exploded view of FIG. 4.”
“FIG. “FIG.6 is a plan view showing a dual cartridge material dispenser, seated in closed 3D printing environments. The cartridges are of different types.
“FIG. “FIG.7” is a plan view showing a material dispensing cartridge located adjacent to a beam source cart in a closed 3D printing environment.
“FIG. 8 shows a plan view for a material dispenser cartridge that is adjacent to a beam source cart, and both cartridges next to a pattern projector.
“With reference to FIG. “With reference to FIG. 1, a thermoplastic material dispensing device 11 is seen depositing material on article 13. The article is kept in an atmosphere free of ambient air. It is protected from molecular contamination, airborne particulates and moisture. The article is protected by a variable volume container described below. The article 13 is made by additive layer deposition. This means that there is relative motion between the article 13 and the nozzle 53 until the layer is deposited. The nozzle is then moved up a little and a second layer is placed over the first layer. This is controlled by a computer. Layer by layer, the deposition process continues until you get a 3D article.
Commercially available printers for 3D printing are: The apparatus described herein, which relates to the handling of material during 3D printing, can be used with software and nozzle position controls. The present invention includes a sterile material supply cartridge and protective variable volume printed article container.
“A supply reel enclosed in sealed container 27 is protected against ambient air. The container has a fixed sheath 23 that contains an internal thermoplastic sterile or at the very least clean filament 25, which is removable within the fixed sheath. The sheath ends at the end distal of the container 27 through a cartridge opening 21. This allows the thermoplastic filament to freely move into the cartridge 17. Cartridge 17 can then be removed from the housing 15. It can be moved up or down by either a support beam or a robot handler (not shown). The cartridge can be attached to the housing 15 using fasteners 19. However, fasteners 19 are fragile and cannot be replaced on the housing if the cartridge is removed. This is for safety reasons. To prevent contamination of the printing systems, it may be desirable to throw away the cartridge and any associated components. Alternatively, the cartridge can be cleaned, sterilized, and re-used with new fasteners.
The drive gear 33 and 35 push the thermoplastic filament 25 through the cartridge. This causes contamination. All components of the cartridge that are contaminated must be removed, including the drive gear, driven gear, idler 41, and capstan 39. The drive motor 31, which is housed in 15 and the drive shaft 37, which projects into the cartridge and locks into the keyhole slot in capstan 39, are both fixed parts that should not be thrown away. The drive motor 31, a stepper motor, advances thermoplastic material incrementally in the same way as a wire puller. The drive gear 35 applies its teeth on the surface of thermoplastic material and pushes it against the idler 41. The frictional interaction between the driven gear and the thermoplastic material results in the material being pulled from the reel-in container 27 to conduit 43.
“The cartridge 17 protects thermoplastic material against exposure to moisture and ambient air. A fin stack 49 is where the conduit 43 runs through. The fin stack is made up of metal fins and is cooled using a thermoelectric chiller 45. Although the fin stack can be removed, the thermoelectric chiller is part of housing 15.
“Conduit 43 is heated to plenum 51, where the thermoplastic material melts. The plenum is made from heat-conductive metal. It has nozzle 53 to allow for the exit of thermoplastic material. While material is being melted in the plenum, some material will attempt to move toward the fin stack 49 at a lower temperature. The fin stack has a temperature gradient with the lower fins being warmer and the upper fins being colder. The nozzle 53 also has a temperature gradient. These two gradients are chosen so that the pressure in the plenum can be relieved by material flow from the nozzle orifice 55, and material backflow into fin stack is very minimal.”
“The plenum 51, nozzle 53, and fin stack 49 are all connected with conduit 43. Since the interior of plenum 51 has thermoplastic material along its walls, and conduit 43 on its walls, all can be discarded when cartridge 17 goes to waste. Or, they may be cleaned and re-used. Housing 15, with drive motor 31, shaft 37, chiller 45, shaft 37 and plenum 51 are all retained for future use. Supply reel 27 with sheath 23, as well as housing 15 with drive motor 31 are also kept. You can replace the supply reel 27 or sheath 23 with other thermoplastic materials, and another cartridge to deposit other materials in other layers.
“With reference to FIG. 2 The housing 15 which contains cartridge 17 and heated plenum 51, as well as nozzle 53, are seen near port 65 in dome67. Dome 67 seals the accordion pleated bellows (61) at the center of a solid cover 69 which acts as a sealed variable volume enclosure. The cartridge 17 is attached to the housing 15, which houses the drive motor 31, chiller 45, and plenum 51. Filamentary material is passed through the fixed sheath 23 between sealed container 27 and heated plenum 51. The bellows (61) have the appearance of a Chinese lantern and serve the purpose of providing a 3D printing environment that is free from moisture and particles for article 13. To allow the article 13 to approach the nozzle orifice 55, the nozzle 53 must be fully inserted into port 65. The bellows will then collapse using support straps 75-76, 77, 78 and 78 to control vertical expansion and contraction. The bellows 61 can be filled with inert gases that can escape through an HEPA (or comparable) filter valve when the bellows fall or stay connected to the inert source. HEPA fabric and Tyvek (TM from DuPont) are selective barrier materials that allow for changes in gas volume but maintain a sterile environment.
“While the nozzle is moving in the Z-direction vertically, the rails 71 and supporting substrate 63, as well as supporting article 13, move in X-direction according to the arrowheads X. The rails 71 are mounted on the table 73, which moves in the Y direction as indicated by arrowheads Y. These X-Y tables can be servo motor controlled and are available commercially. These tables can be controlled by commercial 3D printers using control software. The bellows 61 should be filled with inert gases such as hydrogen or partially inert gases such as carbon dioxide before the nozzle is installed. They also need to remain connected to the inert source of gas during printing. Tyvek bellows will preserve the inner volume of the printing process and allow air to enter or exit to change the volume.
If you choose a bellows material that is air tight, a vent can be installed in the chamber. This will allow for volume changes and maintain sterility. If the bellows are made from Tyvek, or another similar material, it can be folded in a Chinese lantern. U.S. Patent Publication 2015/0217514 describes the configuration. The breathable sterile material will keep the chamber sterile as described in U.S. Patent Publication 2015.
“With reference to FIG. “With reference to FIG. 2. Part of a sealed variable volume enclosure with a dome 67 supporting two housings containing two cartridges 17 & 117. Cartridge 17 is identical to the one shown in FIG. Cartridge 17 is the same as FIG. 1, but cartridge 117 looks like an inkjet cartridge used in commercial dots printing devices. The cartridge 117 contains an ink container 101, which is the same as that used for commercial dots printing, but with a 3D printer-friendly ink. Direct injection of the ink can be done through a conduit (143) and anozzle (153), which are both part of cartridge 117.
“The nozzle 53 extends into dome number 67. Ink might have viscosity which requires heating in heated plenums 151 below the fin stack.149 In such a case, the ink drops flow through conduit 143, through fin stack 149, and into heated plenum 151. This will ensure that heated ink is about the same temperature at the thermoplastic material in heated plenum 51. Prevent premature condensation by heating ink from ink container 101 at the same temperature as thermoplastic material.
“Cartridge 17 uses filamentary plastic material 25 from supply roll 27. This material is delivered to the cartridge via the sheath 23, and then pulled into the cartridge using driven gear 35 against idler 41. The conduit 43 is used to advance the thermoplastic material 25, which passes through fin stack 49, into heated plumb 51, and then out through dome 67’s nozzle 53 and bellows 61. In 3D printing, the two nozzles 53 & 153 work together in simultaneous 3D printing. They use diverse materials and are protected from moisture and particles. FIG. 2 shows how an article is supported. 2. The bellows 61 are moved in the same manner as before.
“With reference to FIG. “With reference to FIG. 1. Each housing and associated cartridge receive thermoplastic filamentary material from the respective sealed containers 127, 227, through a connected fixed sheath (123, 223). The tandem housings are secured on a yoke 120 with slots that can receive the heated plenums of each cartridge 151 and 251. The respective nozzles for each cartridge extend into dome number 67.
“Returning To FIG. 4. A closed print chamber 140 is a flat rectangular bottom with a tubular rigid side wall 130. It looks like a refrigerator food container or plastic microwave. The article can be supported by the bottom 128. A glass or plastic plate may be fused to the bottom of the container to form a part or almost all of the bottom surface. This would allow light energy to flow freely into the bottom of print area. It could also be used to provide energy for laser/UV-activated printing materials. This could allow for printing in an opposite direction to what was described previously. The part and the print plate will rise out of the material pool. The bottom and side walls 130 are still in place. The dome 67 can move vertically through a pleated lid 131. This is controlled by a rigid rod (142) that connects to dome 67 at one end and to an actuator for Z-direction, not shown. The dome’s lateral X-Y motion is controlled by the straps 144 and 146 which push or pull dome67 in the Z direction, and the straps154 and 156 which push or pull dome67 in the direction of the Y. The straps are attached to dome 67 at one end and motion actuators at the other. The motion actuators are located on opposite ends. Motion actuators can be controlled using 3D printing software.
The elastomeric sheet may be used to seal the print chamber 120. However, the nozzles that extend from each cartridge can still come within close proximity of the article being printed. The dome 67 is concentric around the pleats 132, except in the central region 158, where a stack if pleats made of elastomeric materials forms a mini-bellows (148), which is capped by a solid cover 138.
“With reference to FIG. 5. The concentric pleats of closed print chamber 140 contain a central aperture 134. This is sealed by a flange 136, which is attached to the rim of the aperture 134. Fixed rod supports 62 are attached to the flange 136. They can be aligned with rod supports 64 in solid cover 138. Not shown are rods that allow for flexing joinder between solid lid 138 or flange 136, with mini-bellows (148) compressing and expanding on demand between the two members. As dome 67 is pulled up by a vertical rod, as shown in FIG. 4.”
It is expected that the upper dome and its associated duckbill vas will be attached to the lower solid lid/flange with its duckbill vas aligned with those of the upper duckbill. The lower and upper lids will be bonded with pleated material to create a mini-bellow that seals the space between the lower and upper duckbill valves. After printing is complete, the printer nozzle/dispensers will be removed from the lower duckbill valves. This will allow the lower duckbill valves to close and snap shut the air passageway that surrounds the newly printed part. The nozzles can then be removed from the upper duckbill. This will prevent contaminated air from entering the printing space below the lower duckbill valves. The air in the mini-bellows is now considered to be contaminated. Once the nozzles have been removed, the upper dome and pleated material can be torn off and disposed of.
“For applications of food printing, where absolute sterility of the print area post-printing and removal of the nozzles is not required, but cleanliness/sanitation is desired; the upper dome, upper duckbills, and pleated material can be eliminated. This would allow for cost-effective and simple printing while maintaining clean and sanitary conditions. This method of printing objects could be completely cleaned until they are exposed only to very little ambient air after the nozzles have been removed from the printer chamber.
“The tandem housings (115 and 215) receive filamentary material from their respective sealed containers 127, 227, through a connected fixed sheath (123, 223). The nozzles 116, 216 extend from the respective housings 115 or 215, through duckbill seals 416 and 416 into dome 65. Mini-bellows 148 will allow the nozzles to extend into dome 67 through duckbill seals 318, 418 and 610. The Z-motion control can move the nozzles 116 or 216 within close proximity to articles being printed for layer ejection. A UV source of light is used to apply UV radiation when a UV-curable material, as shown in print chamber 140.
“The whole chamber 140 is sealed for partial sterility, and to exclude moisture. Filamentary material is protected against exposure to ambient air by being supplied in sealed containers 127, 227 and into cartridges associated housings 115 or 215. The thermoplastic filamentary material heats up and is ejected through nozzles 116,216 towards the article being printed.”
“FIG. “FIG. 4. Cartridge 325 allows you to deposit filamentary thermoplastic material by using a filament-advancing mechanism, as shown in FIG. 1. Cartridge 425 simultaneously deposits ink from a reservoir 327 via feeder tubes 329. The ink must be compatible with the thermoplastic material. It could also serve as support material for the filamentary materials or vice versa. Cartridge 325 is an inkjet cartridge that is standard, but it can be adapted to 3D printing. When printing with a different ink, the cartridge 425 must be replaced. The cartridge 325 can be removed and replaced if you are using a different type of ink or cleaning. The overall goal is to keep chamber 140 sterile for 3D printing biological articles, food electronics, chemicals, devices, or structures. You can find an inert or non-reactive gas in chamber 140. The gas supply ports on the side walls of chamber 140 (not shown) can be used to maintain the appropriate pressure, regardless of how the chamber’s volume changes.
“3D printing equipment is available to extrude semi-solid paste material in order to perform photoresist dispensing applications. Referring to FIG. FIG. 7 shows how to replace the removable cartridge with a sealed, removable, guided plunger 311 controlled by a controller 315, stepper motor 313, and controller 315. The extrusionnozzle 325 extends through the dual duckbill configuration to allow for sterile printing semi-solid material 317 like photoresist and food items. As previously disclosed, another or third nozzle can be used to spray other materials that have evaporative properties like icing or chemical binder.
“A UV source or laser source 327 could be inserted through any of the dual duckbill configurations to cure deposited material. A tube could be used to provide the chamber 329 with a lens that is attached to the chamber’s closed end. Open ends could be exposed to the outside environment, allowing for the insertion and removal of a UV or laser light beam source 327. The lens tube can be either inserted through the dual duckbill configuration, or sealed and fused to the lid. This allows the laser/UV source energy directed by the XY platform positioning control by the printing equipment. The enclosed print chamber would have a filling tube to allow precise amounts of UV/laser material to be added to the material pool around the printed part. This is done as each layer of raw material reacts to the UV/laser. A wiper attached to the bottom of the lid in the print chamber can be used to level out each layer of liquid material as the X-YZ stage moves. This will prepare for curing with UV/laser energy.
“Additionally, the disclosed embodiment provides a filling tube or evacuation tube that can be used to either dispense powder in the closed chamber or evacuate any material left behind after printing is complete. A wiper attached to the bottom of the lid of the print chamber can be used to level every layer of powdered materials in preparation for sintering with laser energy or binding in place using a binder material sprayed onto it.
“Alternatively, in FIG. “Alternatively, in FIG. The material 317 is contained in a canister, which has a plunger 311. The semi-solid material from the plunger is extruded into the nozzle 325 as it is being formed downwardly. Bellows 329 allow the nozzle to be moved in the XY-Z direction. The nozzle 325 extends through buckbill vales, which are not shown. It terminates above an article that will be manufactured by additive manufacturing. Motor 313 is controlling the plunger 311 and may be controlled by control electronics 315.
“Photoresist can be deposited in a line-shaped pattern and hardened by actinic radiation. The pattern’s width depends on the diameter of the nozzle tip. Wider patterns are formed by parallel lines that overlap. You can also deposit food product in this way.
“A second cartridge, 307, is also secured to dome67. It houses a light source 327 such as a laser. This beam generates a beam 331 of actinic radiation 331, which passes through a nozzle not shown to the area of the tip 325 to cure or harden photoresist. This allows for the formation of line patterns of sterile material within housing 329.
The cartridge can be taken out and replaced once the semi-solid material from the first cartridge 309 has been used up. A cartridge with positive resist material, for example, can be used to create a three-dimensional structure or to separate electrically conductive traces from material with insulative trace. The same goes for cartridge 307, which can be replaced by a light source with a different wavelength or curing characteristics. A light source that is visible may be replaced with a UV source, or an infrared one. To guide the formation of 3D structures, the housing 329 can be moved in accordance with previous descriptions.
“In FIG. “In FIG. Alternatively, a glass-bottom tube could be fused into the lower lid of the sealed printing environment. This arrangement would allow for the use of an LED or DLP projection chip 357 that is inserted into the top tube. The light activated material (e.g. photoresist from 353 in the print area) can be projected onto the tube using this method. This method of transferring energy into the print space could transfer large amounts of the slice geometry from each level into the printer area at once, rather than using a linear extrusion. 3D printing time would be greatly reduced. Laser energy can be directed through the glass window to the print area in patterns that represent a portion. This is a slower method. This energy could be transferred to the print surface faster than linear extrusion, or moving the laser along a straight path.
“Alternatively, see FIG. 8 A material dispense cartridge 353 extrudes semisolid material into the nozzle using any method or means previously described. Photoresist is a preferred material. The light projection cartridge 357 contains a photomask which projects a pattern onto photoresist using the tubular 355 onto a surface. A projected pattern can be either a line or an area pattern. The projection cartridge is connected to a light beam cartridge 365. This directs an actinic radiation beam into the nozzle 351 onto the projected patterns to cure the photoresist. This works in the same way as semiconductor photolithography except that the patterns are created and cured slowly, so bellows 329 moves along XY-Z axes.
An article is formed in a sterilized environment. In order to ensure that the article’s internal surfaces and any external surfaces are safe, body parts such as tissue or bone replacement pieces, as well as human organ repair pieces, may be manufactured in a sealed environment.
Summary for “Cartridge feeder for additive manufacturing”
Due to the increasing popularity of additive manufacturing and technological advances in the field, it is essential to create an efficient dispensing system to manufacture medical devices, electronic components, food, chemicals, and other items. Individuals, doctors, and manufacturing professionals will increasingly use 3D printing systems. This means that there will be an increased demand for different types of 3D printers and tissue. Material dispensers can be quickly and easily exchanged to enable printing of various materials. A Jan. 27, 2015 New York Times article entitled “The Operation Before The Operation?” p. 06 describes the need for anatomical models to aid medicine and the possibility of using 3D printed models.
“The need to make anatomical models as well as actual body parts using additive manufacturing was recognized many years ago. In an article entitled “Rapid prototyping techniques to anatomical modeling and medicine?”, the state of this field was summarized some years ago. by M. McGurk et al. Ann. R. Coll. Surg. Engl. Engl. The creation of models was done by spraying liquid through the ink jet printer nozzles onto a layer precursor powder. This creates a thin, solid slice. Each successive slice was printed until the object reached a ‘green-state. It was then sintered in a furnace. The resultant object was then treated to create a part with full density.
“In recent years, 3D printing large objects has become easier thanks to the advancement of software for computer-controlled robotic XY motion systems used by the semiconductor and optics industry. SolidWorks, AutoCad 360 and similar programs make layering 3D objects easy and cost-effective.
For 3D printing larger objects, the print nozzles must be directed in the XY plane. This can be done by either placing the object on an XY table, where motion is provided below nozzles, or by mounting rails above nozzles to allow for XY motion directed above nozzles. U.S. Pat. demonstrates an XY table that allows motion below the nozzles. No. 5,760,500 to T. Kondo et al. linear actuators or stepper motors provide independent movement to a table above the X-Y plane. U.S. Patent. Describes highly accurate stepper motors that can be used for this purpose. No. 7,518,270 to R. Badgerow & T. Lin. U.S. Pat. describes a 3-D printer with overhead control for nozzles. No. 5,740,051 to R. Sanders et al.”
“In both motion situations, the nozzles move in X-Y relative to the object printed and also move up and down in the Z plane. They start at a lower level and work their way upwards. The first layer, or lamella, is printed at a low elevation. Next, the next layer is printed. Two nozzles may be used. One nozzle is used to extrude or spray a manufacturing material such as polymers, while the second sprays a support fluid. This fluid can be viscous or soft. A support fluid could be an ultra violet light-cured resin, which can be sprayed with ink jet. The faster drying support fluid dissolves when the manufacturing material becomes hardened.
It is well-known that filaments can be used as a source of material for additive manufacturing. In published application 2015/0037446, the authors describe how a gear is used to pull filamentary material into an extruder head. This gear drive is similar in design to U.S. Pat. No. No. 5,816,466 is where consumable welding wire is advanced from a reel by a gear drive mechanism and consumed during the welding process.”
Many medical professionals and researchers are currently looking at additive manufacturing through 3D printing as the future for custom manufacturing. This includes everything from medical devices to biological organs. The flexibility of additive manufacturing allows for the production of diverse items at a lower cost and faster than other manufacturing methods. 3D printing is used to create articles using patient-specific or patient-derived bone, and synthetic tissue and stem cell. In addition to contamination by airborne particles, dust and moisture, additive manufacturing presents a problem. Publication No. Publication No. 2015/0217514, Aug. 6, 2015. The invention was designed to create a system that dispenses thermoplastic and biological materials, which can be used in 3D printing equipment. It is free from dust, airborne particles, and moisture.
“The above object was achieved using a dispenser for additive manufacture that includes a sealed additive material dispensing unit and a filamentary material advancement means. The heating element melts thermoplastic material from filaments and forces the melted material into the nozzle.
“Another embodiment provides a sealed cartridge for inkjet printing of a commercially-available type with a nozzle that directs ink droplets towards a desired area. Both embodiments have the nozzle connected in sealed fashion to the material supply unit. The nozzle is placed in a sealed variable volume material chamber. In this chamber, the nozzle can be vertically moved relative to an XY stage. This enclosure allows for additive material deposit by superposed layers. The dispensing unit as well as the deposition chamber are protected against dust, airborne particles, and moisture during manufacturing. Two nozzles can be ganged side-by-side to print a larger stripe in the XY plane. The spacing of the nozzles should be such that the material ejected by the nozzles forms one solid stripe with no material overlap.”
One nozzle can extrude or spray a material, while the second can be used to spray support material. There are many other nozzle combinations that can be used for additive manufacturing with this technology. For example, two nozzles could dispense dissimilar thermoplastic filaments, while the third would spray a chemical binder. One nozzle sprays a thermoplastic polyjet material, while another nozzle deposits or extrudes bone paste. A third nozzle sprays a bone binder.
Material sprayed or extruded by the nozzles may be a filament pulled out of an enclosed reel or a fluid contained in a sealed container. The first situation is where a filament is pulled out of a sealed container and enclosed in a protective sheath. This sheath is then joined to a movable house. The housing houses a drive motor, a removable cartridge and a drive mechanism that allows the filament to be advanced with the power of the drive motor. The cartridge houses a conduit that holds filamentary material and is controlled by the drive gear. Any thermoplastic or meltable material that can flow after heating can be used as the filamentary material. Bio-materials include filamentary bone, joint substitutes and cellular materials. The housing has a fan that blows air into it to cool the filamentary material and the conduit. The heated part of the cartridge or the cartridge below heats the conduit and starts melting the filamentary materials. Material flows into the nozzle below this heated plenum, where it exits through a bottom aperture onto the deposition layer.
The nozzle must have a length that has a heat gradient greater than the heat gradient in a conduit to allow for one-way flow. A copper nozzle with a shorter length will have a higher heat gradient than a semiinsulative conduit of the same length. This means that heat will flow more to the pipe with a steeper heat slope, which is the nozzle.
“In the case fluid print material, a sealed container communicates fluid to an outlet, or nozzle, as in inkjet printers without the use of a drive gear, heated plenum, or drive gear. To allow fluid to flow and harden after dispensing, the fluid material’s viscosity must be controlled.
The advantage of the removable cartridge’s ability to be replaced or removed after using one material is in favor of another material or for cleaning or sterilization. Different print materials can be used on the same vertical motion stage to enable additive manufacturing without being exposed to dust, airborne particles, or moisture.
The present invention allows additive manufacturing in a sterile environment. It provides a sterile major, expandable chamber for volumetric expansion that allows XY deposition in a sequence to form an object. The sealed entry to the sterile main chamber allows for one or two nozzles to be inserted into the sterile chamber’s major expandable wall chamber. This chamber is used for 3D deposition of objects and a motion in Z for the nozzle or nozzles.
“DESCRIPTION DU DRAWINGS”
“FIG. “FIG.
“FIG. 2. This is a plan view showing a thermoplastic cartridge and dispenser being inserted in a closed 3D printing environment.
“FIG. “FIG.
“FIG. “FIG.
“FIG. FIG. 5. An exploded view of FIG. 4.”
“FIG. “FIG.6 is a plan view showing a dual cartridge material dispenser, seated in closed 3D printing environments. The cartridges are of different types.
“FIG. “FIG.7” is a plan view showing a material dispensing cartridge located adjacent to a beam source cart in a closed 3D printing environment.
“FIG. 8 shows a plan view for a material dispenser cartridge that is adjacent to a beam source cart, and both cartridges next to a pattern projector.
“With reference to FIG. “With reference to FIG. 1, a thermoplastic material dispensing device 11 is seen depositing material on article 13. The article is kept in an atmosphere free of ambient air. It is protected from molecular contamination, airborne particulates and moisture. The article is protected by a variable volume container described below. The article 13 is made by additive layer deposition. This means that there is relative motion between the article 13 and the nozzle 53 until the layer is deposited. The nozzle is then moved up a little and a second layer is placed over the first layer. This is controlled by a computer. Layer by layer, the deposition process continues until you get a 3D article.
Commercially available printers for 3D printing are: The apparatus described herein, which relates to the handling of material during 3D printing, can be used with software and nozzle position controls. The present invention includes a sterile material supply cartridge and protective variable volume printed article container.
“A supply reel enclosed in sealed container 27 is protected against ambient air. The container has a fixed sheath 23 that contains an internal thermoplastic sterile or at the very least clean filament 25, which is removable within the fixed sheath. The sheath ends at the end distal of the container 27 through a cartridge opening 21. This allows the thermoplastic filament to freely move into the cartridge 17. Cartridge 17 can then be removed from the housing 15. It can be moved up or down by either a support beam or a robot handler (not shown). The cartridge can be attached to the housing 15 using fasteners 19. However, fasteners 19 are fragile and cannot be replaced on the housing if the cartridge is removed. This is for safety reasons. To prevent contamination of the printing systems, it may be desirable to throw away the cartridge and any associated components. Alternatively, the cartridge can be cleaned, sterilized, and re-used with new fasteners.
The drive gear 33 and 35 push the thermoplastic filament 25 through the cartridge. This causes contamination. All components of the cartridge that are contaminated must be removed, including the drive gear, driven gear, idler 41, and capstan 39. The drive motor 31, which is housed in 15 and the drive shaft 37, which projects into the cartridge and locks into the keyhole slot in capstan 39, are both fixed parts that should not be thrown away. The drive motor 31, a stepper motor, advances thermoplastic material incrementally in the same way as a wire puller. The drive gear 35 applies its teeth on the surface of thermoplastic material and pushes it against the idler 41. The frictional interaction between the driven gear and the thermoplastic material results in the material being pulled from the reel-in container 27 to conduit 43.
“The cartridge 17 protects thermoplastic material against exposure to moisture and ambient air. A fin stack 49 is where the conduit 43 runs through. The fin stack is made up of metal fins and is cooled using a thermoelectric chiller 45. Although the fin stack can be removed, the thermoelectric chiller is part of housing 15.
“Conduit 43 is heated to plenum 51, where the thermoplastic material melts. The plenum is made from heat-conductive metal. It has nozzle 53 to allow for the exit of thermoplastic material. While material is being melted in the plenum, some material will attempt to move toward the fin stack 49 at a lower temperature. The fin stack has a temperature gradient with the lower fins being warmer and the upper fins being colder. The nozzle 53 also has a temperature gradient. These two gradients are chosen so that the pressure in the plenum can be relieved by material flow from the nozzle orifice 55, and material backflow into fin stack is very minimal.”
“The plenum 51, nozzle 53, and fin stack 49 are all connected with conduit 43. Since the interior of plenum 51 has thermoplastic material along its walls, and conduit 43 on its walls, all can be discarded when cartridge 17 goes to waste. Or, they may be cleaned and re-used. Housing 15, with drive motor 31, shaft 37, chiller 45, shaft 37 and plenum 51 are all retained for future use. Supply reel 27 with sheath 23, as well as housing 15 with drive motor 31 are also kept. You can replace the supply reel 27 or sheath 23 with other thermoplastic materials, and another cartridge to deposit other materials in other layers.
“With reference to FIG. 2 The housing 15 which contains cartridge 17 and heated plenum 51, as well as nozzle 53, are seen near port 65 in dome67. Dome 67 seals the accordion pleated bellows (61) at the center of a solid cover 69 which acts as a sealed variable volume enclosure. The cartridge 17 is attached to the housing 15, which houses the drive motor 31, chiller 45, and plenum 51. Filamentary material is passed through the fixed sheath 23 between sealed container 27 and heated plenum 51. The bellows (61) have the appearance of a Chinese lantern and serve the purpose of providing a 3D printing environment that is free from moisture and particles for article 13. To allow the article 13 to approach the nozzle orifice 55, the nozzle 53 must be fully inserted into port 65. The bellows will then collapse using support straps 75-76, 77, 78 and 78 to control vertical expansion and contraction. The bellows 61 can be filled with inert gases that can escape through an HEPA (or comparable) filter valve when the bellows fall or stay connected to the inert source. HEPA fabric and Tyvek (TM from DuPont) are selective barrier materials that allow for changes in gas volume but maintain a sterile environment.
“While the nozzle is moving in the Z-direction vertically, the rails 71 and supporting substrate 63, as well as supporting article 13, move in X-direction according to the arrowheads X. The rails 71 are mounted on the table 73, which moves in the Y direction as indicated by arrowheads Y. These X-Y tables can be servo motor controlled and are available commercially. These tables can be controlled by commercial 3D printers using control software. The bellows 61 should be filled with inert gases such as hydrogen or partially inert gases such as carbon dioxide before the nozzle is installed. They also need to remain connected to the inert source of gas during printing. Tyvek bellows will preserve the inner volume of the printing process and allow air to enter or exit to change the volume.
If you choose a bellows material that is air tight, a vent can be installed in the chamber. This will allow for volume changes and maintain sterility. If the bellows are made from Tyvek, or another similar material, it can be folded in a Chinese lantern. U.S. Patent Publication 2015/0217514 describes the configuration. The breathable sterile material will keep the chamber sterile as described in U.S. Patent Publication 2015.
“With reference to FIG. “With reference to FIG. 2. Part of a sealed variable volume enclosure with a dome 67 supporting two housings containing two cartridges 17 & 117. Cartridge 17 is identical to the one shown in FIG. Cartridge 17 is the same as FIG. 1, but cartridge 117 looks like an inkjet cartridge used in commercial dots printing devices. The cartridge 117 contains an ink container 101, which is the same as that used for commercial dots printing, but with a 3D printer-friendly ink. Direct injection of the ink can be done through a conduit (143) and anozzle (153), which are both part of cartridge 117.
“The nozzle 53 extends into dome number 67. Ink might have viscosity which requires heating in heated plenums 151 below the fin stack.149 In such a case, the ink drops flow through conduit 143, through fin stack 149, and into heated plenum 151. This will ensure that heated ink is about the same temperature at the thermoplastic material in heated plenum 51. Prevent premature condensation by heating ink from ink container 101 at the same temperature as thermoplastic material.
“Cartridge 17 uses filamentary plastic material 25 from supply roll 27. This material is delivered to the cartridge via the sheath 23, and then pulled into the cartridge using driven gear 35 against idler 41. The conduit 43 is used to advance the thermoplastic material 25, which passes through fin stack 49, into heated plumb 51, and then out through dome 67’s nozzle 53 and bellows 61. In 3D printing, the two nozzles 53 & 153 work together in simultaneous 3D printing. They use diverse materials and are protected from moisture and particles. FIG. 2 shows how an article is supported. 2. The bellows 61 are moved in the same manner as before.
“With reference to FIG. “With reference to FIG. 1. Each housing and associated cartridge receive thermoplastic filamentary material from the respective sealed containers 127, 227, through a connected fixed sheath (123, 223). The tandem housings are secured on a yoke 120 with slots that can receive the heated plenums of each cartridge 151 and 251. The respective nozzles for each cartridge extend into dome number 67.
“Returning To FIG. 4. A closed print chamber 140 is a flat rectangular bottom with a tubular rigid side wall 130. It looks like a refrigerator food container or plastic microwave. The article can be supported by the bottom 128. A glass or plastic plate may be fused to the bottom of the container to form a part or almost all of the bottom surface. This would allow light energy to flow freely into the bottom of print area. It could also be used to provide energy for laser/UV-activated printing materials. This could allow for printing in an opposite direction to what was described previously. The part and the print plate will rise out of the material pool. The bottom and side walls 130 are still in place. The dome 67 can move vertically through a pleated lid 131. This is controlled by a rigid rod (142) that connects to dome 67 at one end and to an actuator for Z-direction, not shown. The dome’s lateral X-Y motion is controlled by the straps 144 and 146 which push or pull dome67 in the Z direction, and the straps154 and 156 which push or pull dome67 in the direction of the Y. The straps are attached to dome 67 at one end and motion actuators at the other. The motion actuators are located on opposite ends. Motion actuators can be controlled using 3D printing software.
The elastomeric sheet may be used to seal the print chamber 120. However, the nozzles that extend from each cartridge can still come within close proximity of the article being printed. The dome 67 is concentric around the pleats 132, except in the central region 158, where a stack if pleats made of elastomeric materials forms a mini-bellows (148), which is capped by a solid cover 138.
“With reference to FIG. 5. The concentric pleats of closed print chamber 140 contain a central aperture 134. This is sealed by a flange 136, which is attached to the rim of the aperture 134. Fixed rod supports 62 are attached to the flange 136. They can be aligned with rod supports 64 in solid cover 138. Not shown are rods that allow for flexing joinder between solid lid 138 or flange 136, with mini-bellows (148) compressing and expanding on demand between the two members. As dome 67 is pulled up by a vertical rod, as shown in FIG. 4.”
It is expected that the upper dome and its associated duckbill vas will be attached to the lower solid lid/flange with its duckbill vas aligned with those of the upper duckbill. The lower and upper lids will be bonded with pleated material to create a mini-bellow that seals the space between the lower and upper duckbill valves. After printing is complete, the printer nozzle/dispensers will be removed from the lower duckbill valves. This will allow the lower duckbill valves to close and snap shut the air passageway that surrounds the newly printed part. The nozzles can then be removed from the upper duckbill. This will prevent contaminated air from entering the printing space below the lower duckbill valves. The air in the mini-bellows is now considered to be contaminated. Once the nozzles have been removed, the upper dome and pleated material can be torn off and disposed of.
“For applications of food printing, where absolute sterility of the print area post-printing and removal of the nozzles is not required, but cleanliness/sanitation is desired; the upper dome, upper duckbills, and pleated material can be eliminated. This would allow for cost-effective and simple printing while maintaining clean and sanitary conditions. This method of printing objects could be completely cleaned until they are exposed only to very little ambient air after the nozzles have been removed from the printer chamber.
“The tandem housings (115 and 215) receive filamentary material from their respective sealed containers 127, 227, through a connected fixed sheath (123, 223). The nozzles 116, 216 extend from the respective housings 115 or 215, through duckbill seals 416 and 416 into dome 65. Mini-bellows 148 will allow the nozzles to extend into dome 67 through duckbill seals 318, 418 and 610. The Z-motion control can move the nozzles 116 or 216 within close proximity to articles being printed for layer ejection. A UV source of light is used to apply UV radiation when a UV-curable material, as shown in print chamber 140.
“The whole chamber 140 is sealed for partial sterility, and to exclude moisture. Filamentary material is protected against exposure to ambient air by being supplied in sealed containers 127, 227 and into cartridges associated housings 115 or 215. The thermoplastic filamentary material heats up and is ejected through nozzles 116,216 towards the article being printed.”
“FIG. “FIG. 4. Cartridge 325 allows you to deposit filamentary thermoplastic material by using a filament-advancing mechanism, as shown in FIG. 1. Cartridge 425 simultaneously deposits ink from a reservoir 327 via feeder tubes 329. The ink must be compatible with the thermoplastic material. It could also serve as support material for the filamentary materials or vice versa. Cartridge 325 is an inkjet cartridge that is standard, but it can be adapted to 3D printing. When printing with a different ink, the cartridge 425 must be replaced. The cartridge 325 can be removed and replaced if you are using a different type of ink or cleaning. The overall goal is to keep chamber 140 sterile for 3D printing biological articles, food electronics, chemicals, devices, or structures. You can find an inert or non-reactive gas in chamber 140. The gas supply ports on the side walls of chamber 140 (not shown) can be used to maintain the appropriate pressure, regardless of how the chamber’s volume changes.
“3D printing equipment is available to extrude semi-solid paste material in order to perform photoresist dispensing applications. Referring to FIG. FIG. 7 shows how to replace the removable cartridge with a sealed, removable, guided plunger 311 controlled by a controller 315, stepper motor 313, and controller 315. The extrusionnozzle 325 extends through the dual duckbill configuration to allow for sterile printing semi-solid material 317 like photoresist and food items. As previously disclosed, another or third nozzle can be used to spray other materials that have evaporative properties like icing or chemical binder.
“A UV source or laser source 327 could be inserted through any of the dual duckbill configurations to cure deposited material. A tube could be used to provide the chamber 329 with a lens that is attached to the chamber’s closed end. Open ends could be exposed to the outside environment, allowing for the insertion and removal of a UV or laser light beam source 327. The lens tube can be either inserted through the dual duckbill configuration, or sealed and fused to the lid. This allows the laser/UV source energy directed by the XY platform positioning control by the printing equipment. The enclosed print chamber would have a filling tube to allow precise amounts of UV/laser material to be added to the material pool around the printed part. This is done as each layer of raw material reacts to the UV/laser. A wiper attached to the bottom of the lid in the print chamber can be used to level out each layer of liquid material as the X-YZ stage moves. This will prepare for curing with UV/laser energy.
“Additionally, the disclosed embodiment provides a filling tube or evacuation tube that can be used to either dispense powder in the closed chamber or evacuate any material left behind after printing is complete. A wiper attached to the bottom of the lid of the print chamber can be used to level every layer of powdered materials in preparation for sintering with laser energy or binding in place using a binder material sprayed onto it.
“Alternatively, in FIG. “Alternatively, in FIG. The material 317 is contained in a canister, which has a plunger 311. The semi-solid material from the plunger is extruded into the nozzle 325 as it is being formed downwardly. Bellows 329 allow the nozzle to be moved in the XY-Z direction. The nozzle 325 extends through buckbill vales, which are not shown. It terminates above an article that will be manufactured by additive manufacturing. Motor 313 is controlling the plunger 311 and may be controlled by control electronics 315.
“Photoresist can be deposited in a line-shaped pattern and hardened by actinic radiation. The pattern’s width depends on the diameter of the nozzle tip. Wider patterns are formed by parallel lines that overlap. You can also deposit food product in this way.
“A second cartridge, 307, is also secured to dome67. It houses a light source 327 such as a laser. This beam generates a beam 331 of actinic radiation 331, which passes through a nozzle not shown to the area of the tip 325 to cure or harden photoresist. This allows for the formation of line patterns of sterile material within housing 329.
The cartridge can be taken out and replaced once the semi-solid material from the first cartridge 309 has been used up. A cartridge with positive resist material, for example, can be used to create a three-dimensional structure or to separate electrically conductive traces from material with insulative trace. The same goes for cartridge 307, which can be replaced by a light source with a different wavelength or curing characteristics. A light source that is visible may be replaced with a UV source, or an infrared one. To guide the formation of 3D structures, the housing 329 can be moved in accordance with previous descriptions.
“In FIG. “In FIG. Alternatively, a glass-bottom tube could be fused into the lower lid of the sealed printing environment. This arrangement would allow for the use of an LED or DLP projection chip 357 that is inserted into the top tube. The light activated material (e.g. photoresist from 353 in the print area) can be projected onto the tube using this method. This method of transferring energy into the print space could transfer large amounts of the slice geometry from each level into the printer area at once, rather than using a linear extrusion. 3D printing time would be greatly reduced. Laser energy can be directed through the glass window to the print area in patterns that represent a portion. This is a slower method. This energy could be transferred to the print surface faster than linear extrusion, or moving the laser along a straight path.
“Alternatively, see FIG. 8 A material dispense cartridge 353 extrudes semisolid material into the nozzle using any method or means previously described. Photoresist is a preferred material. The light projection cartridge 357 contains a photomask which projects a pattern onto photoresist using the tubular 355 onto a surface. A projected pattern can be either a line or an area pattern. The projection cartridge is connected to a light beam cartridge 365. This directs an actinic radiation beam into the nozzle 351 onto the projected patterns to cure the photoresist. This works in the same way as semiconductor photolithography except that the patterns are created and cured slowly, so bellows 329 moves along XY-Z axes.
An article is formed in a sterilized environment. In order to ensure that the article’s internal surfaces and any external surfaces are safe, body parts such as tissue or bone replacement pieces, as well as human organ repair pieces, may be manufactured in a sealed environment.
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