Thermal retention management of heated build chamber in 3D printer

Abstract

A roller thermal isolator (300) configured to cover an opening in a heated build chamber (16) of a 3D printer includes a x-direction non-torsion roller isolator (310) with a first set of non-torsion rollers that retain portions of a x-direction sheet that is held in tension in the x- and y-directions as the tool tray moves in the x-direction. The roller thermal isolator (300) includes a y-direction non-torsion roller isolator with a second set of non-torsion rollers that are located at opposing edges of the opening in the x direction, each of the second set of non-torsion rollers retaining a portion of a y-direction sheet (400, 403) of the thermal isolator (300). Free ends of the y-direction portions of the thermal isolator are held in tension in the x-and y-directions as the tray moves in the y-direction.

Description

THERMAL RETENTION MANAGEMENT OF HEATED BUILD CHAMBER IN 3DPRINTERBACKGROUND

[0001] Additive manufacturing, also called 3D printing, is generally a process in which a three- dimensional (3D) part is built by adding material to form a 3D part rather than subtracting material as in traditional machining. Using one or more additive manufacturing techniques, a three- dimensional solid pail of virtually any shape can be printed from a digital model of the part by an additive manufacturing system, commonly referred to as a 3D printer. A typical additive manufacturing work flow includes slicing a three-dimensional computer model into thin cross sections defining a series of layers, translating the result into two-dimensional position data, and transmitting the data to a 3D printer which manufactures a three-dimensional structure in an additive build style. Additive manufacturing entails many different approaches to the method of fabrication, including material extrusion, ink jetting, selective laser sintering, powder / binder jetting, electron-beam melting, electrophotographic imaging, and stereolithographic processes.

[0002] In a typical extrusion-based additive manufacturing system (e.g., fused deposition modeling systems developed by Stratasys, Inc., Eden Prairie, MN), a 3D part may be printed from a digital representation of the printed part by extruding a viscous, flowable thermoplastic or filled thermoplastic material from a print head along toolpaths at a controlled extrusion rate. The extruded flow of material is deposited as a sequence of roads onto a substrate, which typically is removably supported on a build platform or platen. The deposited material fuses to previously deposited material and solidifies upon a drop in temperature. The print head includes a liquefier which receives a supply of the thermoplastic material in the form of a flexible filament, and a nozzle tip for dispensing molten material. A filament drive mechanism engages the filament such as with a drive wheel and a bearing surface, or pair of toothed-wheels, and feeds the filament into the liquefier where the filament is heated to a molten pool. The unmelted portion of the filament essentially fills the diameter of the liquefier tube, providing a plug-flow type pumping action to extrude the molten filament material further downstream in the liquefier, from the tip to print a part, to form a continuous flow or toolpath of resin material. The extrusion rate is unthrottled and is based only on the feed rate of filament into the liquefier, and the filament is advanced at a feedrate calculated to achieve a targeted extrusion rate, such as is disclosed in Comb U.S. Patent No. 6,547,995.

[0003] In a system where the material is deposited in planar layers, the position of the print head relative to the substrate is incremented along an axis (perpendicular to the build plane) after each layer is formed, most typically by lowering the build platform. The process is then repeated to form a printed part resembling the digital representation. In fabricating printed parts by depositing layers of a part material, supporting layers or structures are typically built underneath overhanging portions or in cavities of printed pails under construction, which are not supported by the part material itself. A support structure may be built utilizing the same deposition techniques by which the part material is deposited. A host computer generates additional geometry acting as a support structure for the overhanging or free-space segments of the printed part being formed. Support material is then deposited pursuant to the generated geometry during the printing process. The support material adheres to the part material during fabrication and is removable from the completed printed part when the printing process is complete.

[0004] High -temperature materials printed using material extrusion techniques are desirably extruded into a heated build chamber, a.k.a. a hot oven. There is a continued need for retaining heat in the build chamber to provide thermal separation and thermal efficiencies, and also to maintain stable build chamber temperatures.SUMMARY

[0005] An aspect of the present disclosure relates to an extrusion-based 3D printer. The extrusionbased 3D printer includes a heated build chamber. The extrusion-based 3D printer includes a roller thermal isolator positioned over an opening in the tool chamber. The roller thermal isolator includes a x-direction non-torsion roller isolator having a tray spanning the opening between the heated build chamber and the tool chamber in a y-direction, the tray movable in the y direction, the tray comprising a tool port within the tray, the tool port movable in the x- direction and a first set of non-torsion rollers, each non-torsion roller of the first set of non-torsion rollers retaining a portion of a x-direction sheet of the thermal isolator, wherein the x-direction sheet of the thermal isolator is held in tension in the x and y directions by compensating for changing diameters of the first set of non-torsion rollers as the tool tray moves in the x direction. The roller thermal isolator includes a y-direction non-torsion roller isolator having a second set of non-torsion rollers, whereineach of the second set of non-torsion rollers is located at edges of the opening and spanning the opening in the x direction, and each of the second set of non-torsion rollers retaining a portion of a y direction sheet of the thermal isolator. Free ends of the y direction portions of the thermal isolator are held in tension in the x and y directions as the tray moves in the y direction by compensating for changes in diameters of the second set of non-torsion rollers as the tray moves in the y direction.

[0006] Another aspect of the present disclosure relates to a roller thermal isolator configured to cover an opening in a heated build chamber of a 3D printer that allows for movement of a tool in the heated build chamber. The non-torsion roller thermal isolator includes a tray spanning the opening between the heated build chamber, wherein the tray movable in the y direction, the tray comprising a tool port within the tray, the tool port movable in the x- direction. The roller thermal isolator includes a x-direction roller isolator having a first set of non-torsion rollers, each non- torsion roller of the first set of non-torsion rollers retaining a portion of a x-dircction sheet of the thermal isolator, wherein the x-direction sheet of the thermal isolator is held in tension in the x and y directions as the tool tray moves in the x direction by compensating for changes in diameters of the first set of non-torsion rollers. The non-torsion roller thermal isolator includes a y-direction non-torsion roller isolator having a second set of rollers, wherein each of the second set of non- torsion rollers is located at edges of the opening and spanning the opening in the x direction. Each of the second set of non-torsion rollers retain a portion of a y direction sheet of the thermal isolator, wherein the y direction sheet of the thermal isolator is held in tension in the x and y directions as the tray moves in the y direction by compensating for changes in diameter as the tray moves in the y direction.

[0007] Another aspect of the present disclosure relates to a method of retaining heat in a heated build chamber of a 3D printer. The method includes providing a roller thermal isolator between a heated build chamber and a tool chamber. The roller thermal isolator includes a tray spanning the opening in the heated build chamber in a y-direction, wherein the tray is movable in the y direction. The tray houses a tool port that is movable in the x- direction. The non-torsion roller thermal isolator includes a x-direction non-torsion roller isolator having a first set of rollers, wherein each non-torsion roller of the first set of non-torsion rollers retains a portion of a x-direction sheet of the thermal isolator, wherein the x-direction sheet of the thermal isolator is held in tension in the x and y directions as the tool tray moves in the x direction by compensating for changes in diameterof the first set of non-torsion rollers. The roller thermal isolator includes a y-direction non-tension roller isolator having a second set of non-torsion rollers, wherein each of the second set of nontorsion rollers located at edges of the opening and spanning the opening in the x direction. Each of the second set of non-torsion rollers retain a portion of a y direction sheet of the thermal isolator and free ends of the y direction portions of the thermal isolator are connected to the tray wherein the y direction sheet of the thermal isolator is held in tension in the x and y directions as the tray moves in the y direction by compensating for changes in diameter of the second set of non-torsion rollers. The method includes positioning a portion of a tool into the heated build chamber through the tool port and moving the tool port with the tool in the x-direction wherein one roller of the first set of non-torsion rollers unwinds a portion of the x-direction sheet and another roller of the first set of non-torsion rollers winds another portion of the x-direction sheet thereon to maintain the x- direction sheet in tension. The method includes moving the tray in the y-direction wherein one non-torsion roller of the second set of non-torsion rollers unwinds a portion of the y-dircction sheet and another non-torsion roller of the second set of non-torsion rollers winds another portion of the y-direction sheet thereon to maintain the y-direction sheet in tension.

[0008] An aspect of the present disclosure relates to an extrusion-based 3D printer. The 3D printer includes an enclosed build chamber having a ceiling comprised of a y-axis deformable thermal insulator and through which an active print head accesses the build chamber to print parts by extruding material onto a platen and an x-y gantry mounted on top of the build chamber and having an x-bridge spanning the build chamber. A print head carriage includes a tool mount for removable installation of one or more print heads and configured for back-and-forth movement along the x- bridge, wherein the x-y gantry is configured to move the carriage in an x-y plane above the build chamber. The 3D printer includes an upward-facing tool tray coupled to or integral with the carriage and having an open bottom providing a tool port for accessing the heated build chamber and an x-axis deformable thermal insulator spanning a length of the x-bridge and coupled to opposite ends of the tray and or the carriage. A thermal barrier is mounted in the tool tray, covers the tool port and penetrable through an aperture thereof. The aperture provides an entry point to the build chamber for the working end of the active print head, wherein when the working end is positioned though the aperture, the tool port is substantially closed.

[0009] Another aspect of the present disclosure relates to a method of swapping tools during a print job in a 3D printer having a heated build chamber. The method includes providing an x-ygantry mounted on top of the build chamber and comprising a x-bridge spanning the build chamber, a print head carriage providing a tool mount for removable installation of one or more print heads and configured for back-and-forth movement along the x-bridge, wherein the x-y gantry is configured to move the carriage in an x-y plane above the build chamber, an upward- facing tool tray coupled to or integral with the carriage and having an open bottom providing a tool port for accessing the heated build chamber, an x-axis deformable thermal insulator spanning a length of the x-bridge and coupled to opposite ends of the tray and or the carriage so as to expand and contract with the back-and-forth movement of the carriage along the x-bridge, the x-axis deformable thermal insulator thereby covering a portion of the build chamber and forming part of the ceiling, wherein the x-axis thermal barrier comprises an aperture configured to expand as a working end of a first print head passes therethrough and configured to contract about the print head once the working end passes through the thermal barrier. The method includes moving the working end of the first print head through the thermal barrier, thereby causing the tool port to be substantially closed. The method includes lifting the first print head from the heated build chamber by passing the working end through the thermal barrier and once the working end is removed from the aperture for a tool swap, the aperture contracts to an area that is less than a maximum cross- sectional area of the working end.

[0010] An aspect of the present disclosure relates to an extrusion-based 3D printer. The 3D printer includes a heated build chamber with opposing side walls, wherein at least one of the opposing side walls includes at least one slot oriented in a z-direction and a platen movable within the heated build chamber in the z-direction. The 3D printer includes at least one support beam extending from the platen, wherein the at least one support beam extends through the at least one slot. The 3D printer includes at least one actuator mounted external to the heated build chamber, the at least one actuator being operably coupled to an end of the at least one support beam to move the support beam in a z-direction and thereby move the platen within the heated build chamber. The at least one support beam includes a first beam extending from the platen to proximate the at least one slot, a second beam coupled to the at least one actuator, and spaced apart first and second beam members positioned through the plurality of slots and connecting the first beam and the second beam. The 3D printer includes at least one insulating seal being in the at least one slot. The at least one insulating seal includes a middle portion that spans a length of the at least one slot wherein the middle portion is sized to be positioned between the spaced apart first and secondbeam members, and first and second outer portions that are secured to the side walls proximate edges of the at least one slot along the length, wherein the first and second outer portions engage an outer edge of the middle portion to form the spaced apart slits through which the spaced apart substantially first and second beam members move to move the platen. The first and second outer portions are deformable to accommodate movement of the beam within the at least one insulating seal while maintaining a seal with the at least one insulating seal.

[0011] Another aspect of the present disclosure relates to a 3D printer. The 3D printer having a heated build chamber with opposing side walls, where each of the opposing side walls define a plurality of spaced apart slots oriented in a z direction. A platen is located within the heated build chamber and movable in the z direction, where the platen includes a plurality of support beams extending from the platen. Each of the plurality of support beams includes substantially flat spaced apart portions extending through one of the plurality of slots. The 3D printer includes a plurality of actuators mounted external to the heated build chamber, where each of the plurality of actuators are coupled to one of the ends of the plurality of support beams with a coupling device. The 3D printer includes a plurality of seals, where each of the plurality of seals being positioned over one of the plurality of slots. Each of the plurality of seals includes a middle portion that spans a length of each of the plurality of slots wherein the middle portion is sized to be positioned between the spaced apart substantially flat portions. Each of the plurality of seals also includes first and second outer portions that are secured to the side walls proximate edges of the plurality of slots along the length, wherein the first and second outer portions abut outer edge of the middle portion, thereby defining spaced apart slits through which the spaced apart substantially flat portions move to move the platen.

[0012] Another aspect of the present disclosure relates to a method of retaining heat while moving a platen within a heated build chamber of a 3D printer. The method includes providing a heated build chamber with opposing side walls, wherein at least one of the opposing side walls includes at least one slot oriented in a z-direction the at least one slot covered with at least one insulating seal comprising a middle portion that spans a length of the at least one slot wherein the middle portion is sized to be positioned between the spaced apart first and second beam members, and first and second outer portions that are secured to the side walls proximate edges of the at least one slot along the length, wherein the first and second outer portions abut an outer edge of the middle portion to form the spaced apart slits. The method also includes providing a platen movable withinthe heated build chamber in the z-direction having at least one support beam extending from the platen, the at least one support beam comprising a first beam extending from the platen to proximate the at least one slot, a second beam coupled to at least one actuator mounted external to the heated build chamber, and spaced apart first and second beam members positioned through the plurality of slots and into the spaced apart slits and connect the first beam and the second beam. The method includes energizing the at least one actuator to move the support beam in a z-direction and thereby move the platen within the heated build chamber where the first and second outer portions deform as the spaced apart first and second beam members move within the at least one insulating seal while maintaining a seal with the at least one insulating seal.BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG. 1 is a perspective view of an extrusion-based 3D printer of the present disclosure having a heated build chamber positioned below a tool chamber.

[0014] FIG. 2 is a perspective view of the 3D printer shown in FIG. 1, with portions of the frame or cabinet removed to illustrate separation of the build and tool chambers and other features in greater detail with an accordion pleated thermal insulator separating the build and tool chambers.

[0015] FIG. 3 is a top view of the accordion pleated thermal insulator of F1G.2.

[0016] FIG. 4 is a view of the 3D printer shown in FIG. 1, illustrating x-y gantry and local Z positioner features, and a roller thermal insulator separating the build and tool chambers.

[0017] FIG. 5 is a view of the 3D printer with a door open to the heated build chamber showing a slot in a wall with a multi-component insulating seal.

[0018] FIG. 6 is an enlarged view of the slot and the multi-component insulating seal

[0019] FIG. 7 is another enlarged view of the slot with the multi-component, insulating seal as illustrated in FIG. 5.

[0020] FIG. 8 is a top view of the slot with the multi-component insulating seal.

[0021] FIG. 9 is a view a print head and a tool tray with a thermal barrier having a tool port for passing the print head therethrough.

[0022] FIG. 10 is another plan view of a portion of the tool tray with the thermal barrier for passing the tool therethrough.

[0023] FIG.l 1 is a plan view of the thermal barrier having a low surface energy coating.

[0024] FIG. 12 is an isometric view of a roller thermal isolator in a 3D printer.

[0025] FIG. 13 is a top view of the roller isolator in the 3D printer.

[0026] FIG. 14 is a side view of a x-direction roller thermal isolator.

[0027] FIG. 15 is an enlarged, side view of a biased tensioner for the x-direction roller thermal isolator.

[0028] FIG. 16 is a schematic view of the x-direction roller thermal isolator with a tool tray in a first position.

[0029] FIG. 17 is a schematic view of the x-direction roller thermal isolator with the tool tray in a middle position.

[0030] FIG. 18 is a schematic view of the x-direction roller thermal isolator with a tool tray in a second position opposite the first position.

[0031] FIG. 19 is a side view of another x-direction roller thermal isolator.

[0032] FIG. 20 is a schematic view of the y-direction roller thermal isolator of FIG. 12 with aX-bridgc in a first position.

[0033] FIG. 21 is a schematic view of the y-direction roller thermal isolator of FIG. 12 with a X-bridge in a middle position.

[0034] FIG. 22 is a schematic view of the y-direction roller thermal isolator of FIG. 12 with a X-bridge in a second position opposite the first position.

[0035] FIG. 23 is an isometric view of another roller thermal isolator in a 3D printer.

[0036] FIG. 24 is a top view of the other roller isolator in the 3D printer.

[0037] FIG. 25 is a view taken along section line 24 — 24.

[0038] FIG. 26 is a schematic view of the other y-direction roller thermal isolator of FIG. 23 with a X-bridge in a first position.

[0039] FIG. 27 is a schematic view of the other y-direction roller thermal isolator of FIG. 23 with a X-bridge in a middle position.

[0040] FIG. 28 is a schematic view of the other y-direction roller thermal isolator of FIG. 23 with a X-bridge in a second position opposite the first position.

[0041] FIG. 29 is a comparative example seal for a support beam for a platen extending through a heated build chamber wall.DETAILED DESCRIPTION

[0042] The present disclosure relates to a 3D printer which provides improved thermal retention within a build chamber where material is extruded to produce printed parts, and thermal isolation between the build chamber and other printer components in non-heated areas of the printer (e.g., a tool chamber). The 3D printer includes thermal insulator components and a thermal barrier that substantially minimize thermal losses in areas where moving 3D printer components penetrate into the heated chamber, and / or move along the walls of the build chamber. The 3D printer includes a dynamic thermal isolator that allows for the movement of a tool carried on a gantry to access the heated build chamber, while substantially minimizing thermal losses, as the tool moves in XYZ directions through the chamber walls. As new printing materials are introduced that require increased build temperatures, such as temperatures approaching and / or exceeding 200 °C, improved thermal retention within the heated build chamber becomes increasing necessary to reduce energy costs, maintain a more consistent and controllable thermal profile, and / or to protect temperature-sensitive equipment, such as electric or plastic components, including a local z gantry, located outside and above the heated build chamber.

[0043] The definition of a tool is any device that can be used in the 3D printer including but not limited to a print head (also called an extruder), a material depositor, a shaping device, a roller, a cutter, a focused heating device such as a laser or heater, focused cooling device, a carbon fiber deposition device, a monitoring device including but not limited to imaging devices and cameras, measurement devices including, but not limited to, lasers and touch probes or any other device that can measure distance, size or features of a part being printed. One such needed thermal insulator forms a ceiling of the heated build chamber. A Z-direction gantry mechanism incrementally lowers a build platform within the heated build chamber as the part is constructed layer-by-layer by extruding material from an active print head onto the build platform.

[0044] The heated chamber ceiling is formed through the use of the dynamic thermal isolator, that moves as the print head is moved in the XY directions by the xy gantry. The dynamic thermal insulator or isolator covers the opening in the ceiling that allows the print heat to move and includes a roller thermal isolator that spans the opening in the ceiling portion that defines a maximum area of a build envelope. The roller thermal isolator utilizes at least one roller sheet that allows the tool to move in the XY directions with x and y gantries, while substantially minimizing heat loss as the tool moves. The tool is required to move freely in XY within the build envelop while penetratingthrough the thermal isolator. The roller thermal isolator forms a portion of a ceiling of the heated build chamber and is configured to isolate heat sensitive components of the tools, the gantries and other 3D printer components such as, but not limited to, other moving parts and bearings, from the elevated temperature in the heated build chamber. Where the tool is an extruder, an extrusion or hot end of the extruder moves within the heated build chamber while the drive components and control components of the extruder are isolated from the elevated temperatures of the heated build chamber. The use of a roller thermal isolator enables the building of objects from high-temperature materials while enabling movement in X and Y, while keeping the heat sensitive components of equipment substantially isolated from the elevated temperatures in the heated build chamber. Further, the roller thermal isolator features facilitate use in large-scale 3D printers by limiting thermal losses around the thermal isolator from the heated build chamber as the tools move in the XYZ directions.

[0045] The roller thermal isolator includes a x-dircction roller isolator having a first set of roller sheets on rotating spools that move in the x direction as the tool is moved in the X direction where the portion of the roller sheets that span the opening remains substantially flat as the tool moves, hi some embodiments, the roller sheet thermal isolator includes a y-direction roller isolator having a second set of roller sheets on rotating spools that move in the Y direction as the tool is moved in the Y direction with the y gantry where the portions of the roller sheets that span the opening remain substantially flat as the tool is moved. Maintaining the substantially flat configuration of the x-direction roller isolator and the y-direction roller isolator as the xy gantries move the tool minimizes openings or gaps between the heated build chamber and the thermal isolator, which increases heating efficiency and temperature uniformity in the heated build chamber and decreases heat loss that can adversely affect heat sensitive components of the 3D printer located outside of the heated build chamber. The x-direction roller isolator and the y- direction roller isolator utilize non-torsion rollers, meaning that the rollers are not biased to roll or unroller with a torsion spring. Rather, rotation of the x-direction and y-direction rollers are synchronized with actuators or timing belts.

[0046] A typical prior art thermal barrier has utilized an accordion pleated or sewn bellows in the ceiling of the heated build chamber to isolate the heated build chamber from the gantry components and the heat sensitive components of the tools. The accordion pleated or sewn bellows can include single pleats or double pleats. Whether single or double pleated accordion bellows,the accordion bellows have minimal open area when in a contracted position; they sit close in proximity to the thermal barrier retention frame, and retain heat in the chamber below. However, when in an expanded position, the ends of the accordion bellows have open “V” shaped ends that do not sit completely in proximity to the thermal barrier retention frame, allowing heated fluid, such as hot air, to escape from the heated build chamber through the “V” shapes and into the space where the gantry components and the tools are housed. The escape of heated air from the heated build chamber results in unnecessary energy consumption, uneven temperature distribution in the heated build chamber, the unnecessary heating of gantry and tool components in the unheated tool chamber above the heated chamber, and possible equipment failure. With an accordion pleated design for a thermal barrier, the stack height of the compressed thermal barrier at each end of the ceiling limits the print area or envelope by preventing the print head moved by the x-y gantry from reaching the outer edges. As such, as 3D printers become larger in both the X and Y directions, more accordion stack height is required, which in turn requires the 3D printer to be even larger in the X and Y directions, to accommodate the increased stack height or thickness of the compressed accordion pleated thermal barrier.

[0047] In the present disclosure, the disclosed thermal isolator, having first and second sets of roller sheets moving in the X and Y directions, is capable of being utilized with large-scale 3D printers, as the sets of roller sheets are functional in covering large print envelopes as the print head moves, without limiting the print head’s reach into the comers of build envelop in the X and Y directions, unlike the compressed accordion pleated thermal barrier. Large-scale 3D printers include build envelopes that are 24 in. by 24 in. (576 sq. in.), 24 in. by 40 in. (970 sq. in.), 32 in. by 40 in. (1,280 sq. in.) and higher. However, the presently disclosed roller sheet thermal isolator can also be used with 3D printers with smaller build envelopes.

[0048] A typical larger-scale thermal barrier using accordion or sewn bellows needs to be flexible and lightweight. However, with ever-larger X-Y area requirements, the portions of the larger accordion- style bellows can also sag or buckle down into the print plane and interfere with a part being printed. The use of the roller sheet thermal isolators in tension can maintain a substantially flat interface with the ceiling frame defining the opening of the build envelope, as the print head is moved in the x-y plane by the x-y gantry. If the roller sheet thermal isolator is not maintained in a taut manner, it will also sag in the build chamber, or lift from the ceiling framedue to the strong airflow movement in the heated build chamber, providing an unacceptable source of heat leakage.

[0049] Due to economic constraints on the cost of the thermal isolators and the size of the actuators for moving the tool carriage, lightweight and inexpensive materials can be used to provide expansion and contraction of the sets of roller sheets while being able to withstand high print chamber temperatures and provide the necessary thermal isolation for utilizing the tool gantries and tools with heat sensitive components which reside above the heated chamber. A nonlimiting, exemplary material of construction includes polytetrafluoroethylene (PTFE) coated fiberglass fabric which has sufficient flexibility to readily roll and unroll from a spool or roller. Other alternative materials of construction for the roller sheets include, but are not limited to, silicone coated silica, silicone coated fiberglass, Kevlar®-glass textile, and aluminized fabric.

[0050] The present disclosure is also directed to 3D printers having a heated build chamber and a separate tool chamber positioned above the heated build chamber. The tool chamber includes a tool rack for holding print heads and optionally, other build tools for use in constructing the part. The heated build chamber and the tool chamber are separated by a thermal insulator in a system which allows a nozzle of a print head to extend from the tool chamber into the heated build chamber for extruding material to build the part on the build platform. The tool changer allows for switching between a plurality of different printing tools retained outside the heated print chamber. The hot or working ends of print heads and other tools are inserted into the heated chamber through a tool port for use in printing a 3D part, then removed when a tool change is commanded during that part build.

[0051] As the various hot ends of print heads are positioned into and removed from the heated build chamber, the tool port can serve as a large source of heat loss, particularly as print head size increases and oven temperature requirements are hotter. The present disclosure also includes a thermal barrier for covering the tool port. The tool port thermal barrier aids in retaining heat that would otherwise escape from the heated build chamber through the tool port. An aperture of the thermal barrier conforms to the shaft of the inserted print head hot end, which is in some cases has a print head heating tube narrower than a nozzle tip of the hot end. The thermal barrier also aids in retaining heat within the heated build chamber by reducing or sealing the tool port when no tool is inserted.

[0052] There also is a need to retain the heat within the heated build chamber not only at the ceiling of the print space, but in any other access points as well. In some printer configurations such as shown and described herein, the printer’s build platform or platen is supported by beams that project through slots in walls of the build chamber for engagement with a gantry mechanism (e.g., motors) located outside of the heated environment, wherein the beams move in a Z direction to increment the platen away from the extruder as material is deposited in layers. In the prior art, overlapping flaps of flexible material were used as insulating seals to reduce heat loss through the slots while allowing the beams to move in the Z direction within the slots. But as the size of a printer increases, and more robust platen beams are utilized to provide sufficient strength to support larger and heavier parts built on larger and heavier platens, the size or cross-sectional area of the beams intersecting the chamber walls causes gaps in the overlapping flap-type insulating seals, allowing heat to escape the heated build chamber (as illustrated in FIG. 29 and discussed below). In some instances, leakage points within the insulating seals can also cause non-uniform thermal profiles within the chamber. As described in more detail below, the present disclosure includes a multicomponent, insulating seal that substantially seals the side access slots in the walls as the platen moves in the Z direction. The sealing of the slot can reduce heat from exiting the heated chamber.

[0053] The present disclosure may be used with any suitable additive manufacturing system, commonly referred to as a 3D printer. For example, FIGs. 1-5 illustrate a 3D printer 10 having features as discussed above. FIG. 1 is a perspective view of the 3D printer enclosed in cabinets. FIGs. 2-4 are perspective views or side views of the 3D printer with portions removed to illustrate internal features more clearly. As shown initially in FIGs. 1 and 2, 3D printer 10 includes a build chamber cabinet 12 housing a heated build chamber 16 and a tool chamber cabinet 14 housing a separate tool chamber 18, with the tool chamber 18 positioned on top of the build chamber. The tool chamber 18 houses multiple tools, in a tool rack 22, including, but not limited to, selectable print heads 24. The 3D printer 10 includes a print head carriage 26 which connects or couples to a selected tool or print head, with an x-y gantry 28 moving the carriage 26 and a selected print head or tool in an x-y plane above a build plane within the heated build chamber 16. The build plane is provided by a platen or platen assembly 30 (shown in FIGs. 4 and 5) within the heated build chamber 16, with the platen 30 being moved in a vertical z direction within the build chamber by a platen gantry 32, typically four independently controllable linear actuators. The unheated toolchamber 18 and the heated build chamber 16 are separated by a thermal insulator 20 which minimizes heat loss from the heated build chamber 16 into the unheated tool chamber 18.

[0054] The thermal insulator 20 can be a deformable thermal insulator which allows x-y movement of the print head 24 across the build space. An example of a deformable thermal insulator 20 is disclosed in Stratasys U.S. Pat. No. 7,297,304. The thermal insulator 20 allows the build environment to be maintained at an elevated temperature while preventing the same elevated temperature in tool chamber 18. Retaining the electronic components of the print head 24 or other tool outside of the heated build chamber 16 can extend the life of the print head 24 or other tool as typically, the electronic portions of the print head 24 or other tool cannot survive the elevated temperature of the build environment. Maintaining a lower temperature in the tool chamber 18 also aids in extending the life of moving parts, such as the XY gantries, other electric motors or actuators and / or bearings. As consumers desire more sophisticated materials with higher glass transition temperatures, the heated chamber must be capable of operating at temperatures higher than 150 degrees C, and in some cases, higher than 200 degrees C. Heat loss can be significant if the build chamber is not insulated well.

[0055] Referring to FIG. 2 and 3, the thermal insulator 20 of 3D printer 10 is illustrated as comprising accordion pleated y-direction thermal insulators 20A and x-direction thermal insulators 23. Referring to FIG. 4, the thermal insulator 20 of 3D printer 10 is illustrated as comprising roller thermal insulators. In either embodiment, the x-direction and y-direction thermal insulators comprise the ceiling of the heated build chamber 16. The y-direction thermal insulators 20A are connected to opposing outer surfaces of a X-bridge 60, such that as the X-bridge 60 is moved in a y-direction by an x-y gantry 28, one thermal insulator expands and the other thermal insulator contracts.

[0056] As best shown in Fig. 3, the x-direction thermal insulators 23 are seated in a tray 31 that may optionally support the X-bridge 60 or be supported by the X-bridge 60. Alternatively, in some embodiments the tray 31 is integral with the X-bridge 60. Also seated in tray 31 is a tool tray 201, which is coupled to or integral with the print head carriage 26 and carries an active print head 24, and also is coupled to and positioned between the x-direction thermal insulators 23. The tool tray 201 reciprocates in the x-direction as the x-y gantry 28 moves the print head 24 (e.g., indirectly by moving the print head carriage 60 or the tool tray 101), and the x-direction thermal insulators 23 on either side of the tool tray 201 move back and forth and deform accordingly tomaintain the thermal insulation between chambers. The tool tray 201 further houses a thermal barrier 200 positioned over an access port to the build chamber (the “tool port”). The thermal barrier 200 includes an aperture 206 that provides access for a tool or the print head 24 to enter into and exit the heated build chamber 16 while minimizing heat loss during a part build.

[0057] In an exemplary embodiment of the 3D printer 10, the print head 24 is shown engaged on a tool mount of the carriage outside of the heated build chamber 16, and has an inlet 29 for receiving a consumable build material and a nozzle 25 for dispensing the build material onto the platform in a flowable state. The consumable build material can be provided to the print head 24 from one or more filament spools positioned within spool cabinets 56 positioned on the sides of the build chamber, and through filament guide tubes 54 extending from the spool cabinets to the print head.

[0058] Referring to FIGS. 2 and 4, the x-y gantry 28 is mounted on top of and outside of the heated build chamber 16, and in an exemplary embodiment comprises the X-bridgc 60, Y-rails 52, and associated X and Y motors for moving and positioning the carriage 26 (and any build tool installed on the carriage) in an x-y plane above the build plane. The carriage 26 includes a tool mount 27 for receiving and retaining print heads 24 or other tools and a local Z positioner 72 for controllably moving a retained print head or other tool out of the x-y build plane along a perpendicular z direction axis. The local Z positioner 72 operates to move a retained print head in a limited Z band of motion from a build position within the heated build chamber, to a tool change position in the tool rack 22 outside the build chamber, during a pail build. In some embodiments, the local Z positioner 72 may be utilized while the carriage is moving in x-y or when it is in a fixed x-y position. The x-y gantry, as well as the local Z positioner, can utilize any suitable motors, actuators or systems to move the carriage and print head or other tool in the x, y and z directions as discussed.

[0059] The tool rack 22 is located above the heated build chamber 16 at a position reachable by the tool mount 27 when elevated by the local Z positioner 72. The tool mount 27 may engage with and support a print head 24, and is used to retain and swap print heads provided in the rack, and once put into service, the hot end with the nozzle 25 is positioned into the heated print chamber 16, while the x-y gantry and print head electronics remain outside the heated build chamber 16. In general, any modular tools, such as print heads or any other tools that are removably and replaceably connectable to a 3D printer may be stored in bins of a tool rack outside the heatedchamber for managing tool inventory and interchanging tools during operation of the 3D printer. The local Z positioner 72 is utilized for picking and placing tools in the bins so that the 3D printer 10 can interchangeably use the various modular tools contained in the tool rack 22 during a part build, either sequentially, or simultaneously. The tool rack 22 may be any suitable combination of containers or other defined spaces for receiving and storing tools.[00601 The 3D printer 10 also includes controller assembly 38, which may include one or more control circuits (e.g., controller 40) and / or one or more host computers (e.g., computer 42) configured to monitor and operate the components of 3D printer 10. For example, one or more of the control functions performed by controller assembly 38, such as performing move compiler functions, can be implemented in hardware, software, firmware, and the like, or a combination thereof; and may include computer-based hardware, such as data storage devices, processors, memory modules, and the like, which may be external and / or internal to the 3D printer 10.

[0061] Controller assembly 38 may communicate over communication line 44 with print head 24, filament drive mechanisms, chamber 16 (e.g., with a heating unit for chamber 16), head carriage 26, motors for platen gantry 32 and x-y or head gantry 28, motors for local Z positioner 72, motors for the roller thermal insulator 20 and various sensors, calibration devices, display devices, and / or user input devices. In some embodiments, controller assembly 38 may also communicate with one or more of the platen 30, platen gantry 32, x-y or head gantry 28, and any other suitable component of 3D printer 10. While illustrated as a single signal line, communication line 44 may include one or more electrical, optical, and / or wireless signal lines, which may be external and / or internal to 3D printer 10, allowing controller assembly 38 to communicate with various components of 3D printer 10.

[0062] During operation, controller assembly 38 may direct platen gantry 32 to move platen 30 to a predetermined z height within the heated build chamber 16. Controller assembly 38 may then direct x-y gantry 28 to move head carriage 26 (and the retained print head 24) around in the horizontal x-y plane above chamber 16, and direct the local Z positioner 72 to move the head carriage in the z direction relative to the x-y plane, in addition to the platen gantry z movement. The movement in z may be done during the extrusion of material from the print head, or when removing or inserting a print head into the build chamber. Controller assembly 38 may also direct a retained print head 24 to selectively advance successive segments of the consumable filaments from consumable spools 50 (not shown, located in filament cabinets 56) through filament guidetubes 54 and into the print head 24. It should be noted that movements commanded by the controller assembly 38 may be directed serially or in parallel. That is, the print head 24 can be controlled to move along the x, y and z axes by simultaneous directing the x-y gantry 28 and the local Z positioner 72 to re-position the head carriage 26 along each axis.

[0063] At the start of a build process, the build plane is typically at a top surface of the build platform or platen 30 (or a top surface of a build substrate mounted to the platen) as shown in FIG. 5, where the platen 30 is positioned to receive an extruded material from the nozzle 25 of the print head 24. The start of a build process begins with the platen 30 proximate a top region of the heated build chamber 16. As layers are printed, the platen 30 is indexed away from the build plane, allowing printing of a next layer in the build plane. The platen gantry 32, or primary Z positioner, moves the build platform away from the print plane in between the printing of layers of a 3D fabricated part 74 (shown in FIG. 4). One or more parts and associated support structures can be printed in a laycr-by-laycr manner by incrementally lowering the platen in the z direction. FIG. 4 illustrates portions of 3D printer 10 with the platen 30 at a lowered position, achieved through numerous incremental z direction repositioning steps while printing.

[0064] As discussed, the build chamber 16 of the 3D printer may be heated to provide a heated or ovenized build environment, such as in the case of FDM® 3D printers manufactured and sold by Stratasys, Inc. of Eden Prairie, MN. The heated build chamber 16 is provided to mitigate thermal stresses within a printed part, or to anneal the part, and other difficulties that arise from the thermal expansion and contraction of layered build materials during fabrication of a layered part, using methods such as are disclosed in U.S. Pat. No. 5,866,058. The thermal management system of the present disclosure aids in retaining heat within the heated build chamber 16 by providing thermal insulators to increase thermal retention as the x-y gantry, and local Z positioner, moves the print head 24 or tool and a penetrable thermal barrier over and into the tool port.Heated Build Chamber Seals for Platen-Support Beams

[0065] The thermal management system of the present disclosure includes insulating seals 100 in slots 17 in the walls 15 of the heated build chamber 16 as shown in FIG. 5. While one slot 17 and insulating seal 100 is illustrated, the heated build chamber 16 includes four slots, one slot 17 for each support beam 109 extending from the four comers of the platen 30.

[0066] Referring to FIGS. 5-8, a central insulating member 130 of the multicomponent, insulating seal 100 is located in the area between the substantially flat, spaced apart beam members 102 and 104 of the support beams 109 and substantially cylindrical outer portions of the seal are located adjacent to outer edges of the central insulating member. The central insulating member and the substantially cylindrical outer portions substantially seal the slot in the chamber and provide sealed slits through which the substantially flat, spaced apart beam members of the support beam extend from the platen to the linear actuator. The insulating members remain substantially static while allowing the beams to move in the z direction.

[0067] A slot 17 is illustrated with one end of beam members 102 and 104 attached to substantially vertical webs 106 and 108 of a platen beam 110 where the beam members 102 and 104 extend through the slot 17. The beam members 102 include rounded upper and lower edges101 and 103 such that as the beam members 102 and 104 move within the insulating seal 100, the beam members 102 and 104 slide within and do not grip the insulating seal 100.

[0068] Other ends of the beam members 102 and 104 are attached to an actuator beam 120, which are also attached to a linear actuator 122 as best illustrated in FIG. 8. The beam members102 and 104 rigidly secure the support beam 110 to the actuator beam 120 such that as the linear actuator 122 is energized, the actuator beam 120 and the support beam 110 move which causes the platen 30 to move.

[0069] Collectively, the platen beam 110, the beam members 102 and 104 and the actuator beam 120 form a support beam 109 from the platen 30 to the actuator 122. In other embodiments, the support beam 109 can be a unitary structure from the platen 30 to the actuator 122.

[0070] Referring back to FIGS. 6-8, a central insulating member 130 spans a height of the slot 17 and includes a support member 132 having a U-shaped cross-sectional configuration and an insulating material 134 attached to a flat portion 133 of the support member 132. The support member 132 extends beyond a top edge and a bottom edge of the slot 17 and is attached to the wall 15 of the heated build chamber 16 above the top edge and below the bottom edge. The insulating material 134 is in the form of a rectangular prism where a width is about the distance between rounded upper and lower edges 101 and 103 of beam members 102 and 104 of the beams such that the insulating material 134 engages the rounded edges 101 and 103. The engagement of the rounded edges 101 and 103 with the insulating material 134 minimizes wear of the insulating material 134 as the beam members 102 and 104 move within the slot 17 and past the local surfacesof the insulating material. The insulating member can be any suitable configuration to provide an inner seal between and on the sides the beam members 102 and 104. When the platen is moved in the z direction, the beam members move within the slits, the insulating material is compressed at the current location of the beam members. The insulating member conforms to the movement of the beam, and springs back when the beam has passed by any particular location along the slot, filling the slot gap to reduce air leakage in the heated chamber.

[0071] The materials of construction for the insulating members can include any suitable heat resistant deformable insulating materials including, but not limited to, high temperature silicone compounds, fluoro-elastomeric foam compounds, or the like. The insulating material 134 of the central insulating member 130 and the outer seals 140 and 142 are covered in a heat-resistant flexible covering, for example a flexible heat resistant foam piping or welt cording, The exterior surface of each of the insulating members may also be covered with wear-resistant or slippery material such as fiberglass, PTFE coated fiberglass, braided or mesh steel with a low friction coating, PTFE sheeting or woven fabric fibers or other heat resistant materials.

[0072] Angled support members 124 and 126 are attached to the walls 15 of the heated build chamber 16 proximate to the vertical edges 128 and 129 of the slots 17. Substantially outer seals 140 and 142, which are substantially cylindrical and tubular in configuration, are attached to the angled support members 124 and 126 along the length of the vertical edges 128 and 129. The overall shape of the seals can be varied, to suit the design needs of the support member configuration, and are constructed of a similar insulating material as used for the insulating material of the central insulating member 130, as described above. The substantially cylindrical seals 140 and 142 protrude into the slot 17 and contact the side edges of the insulating material 134 to form slits 144 and 146 through which the beam members 102 and 104 move.

[0073] As the beam members 102 and 104 move in the slits 144 and 146, the substantially cylindrical seals 140 and 142 compress or deform at the area of contact with the beam members 102 and 104 to maintain a seal with the insulating material 134 about the beam members 102 and 104, while the remaining length of the slits 144 and 146 remain sealed between the cylindrical seals 140 and 142 and the edges of the insulating material 134. While substantially cylindrical seals 140 and 142 are described and illustrated, other configurations of the outer members of the seal 100 can be utilized provided slits that are formed with the central insulating member 130 and substantially seal about the beam members 102 and 104 as the beam members 102 and 104 aremoved in the z direction. The other cross-sectional configurations of the seals 140 and 142 include, but are not limited to, hemi-spherical, oval, rectangular and / or elliptical cross-sectional configurations. Whatever configuration of the outer seals 140 and 142, the ability to deform as the beam 110 moves through the slits 144 and 146 and be sufficiently resilient to return to a relaxed state after the beam passes to limit the gaps in the slits 144 and 148 is sufficient for the seals 140 and 142 to be utilized.

[0074] In some embodiments, the support member for the platen may have one solid plate instead of two beam members, with one entry point into each corner. In this case, there would be only one entry slit, and two cylindrical seals to insulate either side of the gaps, without the use of the central insulating member 130.

[0075] To compensate for the configuration of the beams, substantially vertical beam members are attached to both the end of the beams within the heated build chamber and to beams exterior to the heated build chamber, which arc connected to the linear actuators that move the platen in the Z direction. The substantially vertical beam members are located through slots in the heated build chamber, and create a beam extending from the build platen to the linear actuators, allowing for movement of the platen within the heated build chamber.

[0076] In some configurations, an alternative, and / or in addition, to beams using beam members includes providing cut out areas in webs of the beams that intersect with the slots in the heated build chamber. By cutting out portions of the beams at the intersection with the slots, vertical sidewalls of the beam can travel within the slits to provide the seal to the slots in the heated build chamber walls.

[0077] The insulating seal 100 retains heated gas, such as heated and circulated air, within the heated build chamber 16 while allowing the platen 30 to move using linear actuators 122 mounted outside the heated build chamber 16 by forming a seal with the beam members 102 and 104 extending through the slots 17. It will be understood that while the use of one slot 17 with the insulating seal 100 and beam members 102 and 104 are described and illustrated, the remaining three slots will include the same seal 100 and the same beam members 102 and 104 will be attached to the support beams 110 extending from the other comers of the platen 30.Thermal Barrier for Tool Port

[0078] Print heads, or tools need an access point aka tool port into the oven for the hot end to be inserted into the heated build chamber 16 during the printing operation. The tool working end can be a round heated tube or barrel, although it may also be in other geometries such as rectangular, triangular, oval, and the like. A flexible and accommodating thermal barrier flexes as the print head or tool is inserted into the heated printing chamber 16, and conforms to the exterior surface of the print head hot end. The thermal barrier is sufficiently resilient to return to its unflexed position when the print head is removed from the tool port, in order to minimize heat loss from the gap about the outside perimeter of the inserted tool at the access point to the heated build chamber 16.

[0079] Referring to FIGS. 9 and 10, a thermal barrier 200 is located within the tool tray 201. The tool tray 201 is upward facing and includes an opening 202 in the top that leads to a space defined by a front wall 205, a back wall 207, a left side wall 209 and a right side wall 21 1. A bottom surface 213 providing a tool port attaches to the front wall 205, the back wall 207, the left side wall 209 and the right side wall 211.The thermal barrier 200 is supported on the bottom surface 213 covering the tool port, where its aperture 206 allows entry to the build chamber. The aperture 206 of thermal barrier 200 in some embodiments expands to allow a tool (e.g., a nozzle or hot end of a print head) to passes through the aperture 206 and returns to a substantially constricted configuration once the tool (or a wider portion of the tool) passes through or is removed from the aperture 206.

[0080] Referring to FIGS. 9-11, the thermal barriers 200 includes a complementary configuration to that of the bottom wall 213. In one embodiment, the thermal barrier 200 is fabricated from one solid material. In another embodiment, an elastomeric material 252 of the thermal barrier 200 is coated with a low surface energy material 259 that is substantially abrasion resistant, such as shown in FIG. 11. The thermal barrier material 200 can be an elastomeric composition, in order to allow deformation and conformance to the surfaces of the tool when the tool is inserted into the access port, and to return to its original shape once the working end of the tool passes through and when the tool is removed from the access port. The material of the thermal barrier 200 can also be heat tolerant and abrasion resistant through the aperture. In some embodiments, the thermal barrier is a multi-layer material construction, for example, a layer of silicone rubber or other elastomeric material sandwiched between top and bottom layers of a tough, low surface energy material such as a PTFE-coated fiberglass material.

[0081] Referring back to FIGS. 9 and 10, a clamping device 263 retains the thermal barrier 200 in a substantially fixed position within the tool tray 201. The clamping device 263 is constructed of a flexible, resilient material such as sheet metal, where the clamping device 263 is configured to engage an upper surface of the thermal barrier 200. The clamping device 263 includes an opening over the aperture 206 of the thermal barrier 200 sized sufficiently that a working end of a print head can pass through it as it passes through the aperture 206.

[0082] With the thermal barrier 200 for the tool 24 retained within the tool tray 201 with the clamping device 263, a tool can be inserted through the aperture 206 in the thermal barrier 200 where the aperture 206 can be expanded in diameter by forcing the material between the plurality of slits 254 downward in the Z direction. Once a wider portion of the tool is through the aperture 206, the material between the plurality of slits 254 returns to a substantially flat configuration where the perimeter 253 that is covered by the material of the upper and lower layers 259 is proximate the tool and substantially prevents heated air from leaking about the aperture 206 and the tool.

[0083] The thermal barrier 200 minimizes leakage of hot air from the heated build chamber into the tool chamber while a print head or tool is in use in the heated chamber. The thermal barrier 200 also minimizes the leakage of air from the heat build chamber as one tool is swapped for another tool by reducing the open area in the thermal barrier 200 relative to the open area in the opening of the bottom wall 113.

[0084] When the overall printer configuration has an unheated tool chamber above the ceiling of the heated print chamber, there is a strong potential to overheat the unheated print tool chamber to unacceptable temperatures. During the printing of a part in a heated chamber, the oven temperature often may exceed temperatures of 200 °C. Sensitive electronic portions of each print head tool are kept outside the heated print chamber to attempt to maintain heat exposure to below a threshold of 80 °C. When a tool port is left uncovered (e.g., by removing the thermal banner) hot air can flow freely from the heated chamber into the tool chamber during a tool swap, and as a result the temperature in the unheated tool chamber has been observed to exceed the 80 °C threshold when operating without the thermal barrier. The use of a thermal barrier of the present disclosure minimizes the tool port opening, which aids in retaining heat in the heated build chamber as the print heads are swapped, which in turn aids in retaining the unheated tool chamber below the 80 °C threshold.Roller Thermal Isolator

[0085] The ceiling portion of the heated chamber requires a thermal insulator to provide heat retention, while allowing for print head gantry movement; some are a pleated style, with opposing sets of pleats in X and in Y. The pleating allows quick print head movements in the XY direction, while maintaining a thermally sealed ceiling region of the heated chamber. The pleating, however, does allow for heat leakage from the ceiling of the heated chamber through small gaps between the pleats where they rest in a frame which holds the thermal isolator to the side walls of the printer. With a small printer XY area or size, this heat leakage upward into the unheated chamber above is not significant. As the size of printers increase, the leakage from the ceiling thermal insulator pleats increases significantly, and there has been a desire to minimize that source of leakage by keeping the thermal insulator as close to the ceiling frame as possible at all locations. As the temperature requirements for high glass transition temperature (Tg) materials increase, the much-increased temperatures of the heated chamber require that the heat be better contained within the heated space.

[0086] Referring to FIGS. 12-15, a dynamic roller thermal isolator 300 can be utilized to minimize leakage locations. The roller thermal isolator 300 separates the heated build chamber 16 and the unheated tool chamber 18, just as the previous pleated styles did, but can function differently. The roller thermal isolator 300 includes a x-direction roller isolator 310 and a y- direction roller isolator 400.

[0087] In FIG. 12, the roller thermal isolator 300 provides a sufficient barrier to retain equipment in the unheated tool chamber 18 above the heated chamber, below a critical operating temperature. By way of non-limiting example, with the state of the technology as of this filing, the maximum operable temperature for equipment in the unheated tool chamber 18 is about 80°C. At temperatures consistently above 80°C, electronics and moving equipment begin to fail or warp. The critical temperature will change based upon advances in technology and material selection, and will be equipment dependent using the current technology.

[0088] The x-direction roller isolator 310 is located within the X-bridge 60 and includes the aperture 206 within the tool tray 201 configured to allow a tool to pass there- though and into the heated build chamber 16. The X-bridge 60 spans an opening between the heated build chamber 16 and the unheated tool chamber 18 in the y direction and is movable in the x direction.

[0089] The x-direction roller isolator 310 includes two separate sheets of material 312 and 314 where the sheet of material 312 is wound into a coil form onto a first roller 316 and the sheet of material 314 is wound into a coil form onto a second roller 332. The first roller 316 is rotatably mounted to the tool tray 201 a distance from the aperture 206. An end 320 of the first sheet of material 312 is secured to a biased tensioner 322 that spans a width of the first sheet of material 312 in the y-direction where the biased tensioner 322 and the first roller 316 retain the first sheet of material 312 in tension in the y direction.

[0090] The biased tensioner 322 includes a rigid member 321 with an arcuate surface 319 that spans the width of the first sheet of material 312. The end 320 of the first sheet of material 312 is positioned about the arcuate surface 319 and into a recess 323 in the rigid member 321. A retaining strap 325 is positioned over the end 320 of the first sheet of material 312 and into the recess 323. The first sheet of material 312 is placed into tension proximate the end 320, and a plurality of bolts 327 engage threaded bores in the rigid member 321, such that the plurality threaded bolts 327 frictionally retain the end 320 in tension between the rigid member 321 and the retaining strap 325.

[0091] The biased tensioner 322 includes stationary members 324 and 326 that are non- movably secured to the X-bridge 60 proximate ends of the rigid member 321. Compression springs 228 and 230 are positioned in cavities in the stationary member 224 and 226 and the rigid member 321, where the compression springs 228 and 230 bias the rigid member 321 away from the first roller 316 in the x direction such that tension is retained on the sheet of material 312. The biased tensioner 322 aids in keeping the first sheet of material 312 taut as the diameter of the material on the first roller 316 changes as the tool tray 201 is moved in the x direction.

[0092] The second roller 332 is rotatably mounted to the tray 207 a distance from the first roller 316 and at a location on an opposite side of the aperture 206. An end 313 of the second sheet of material 314 is secured to a biased tensioner 336 that spans a width of the second sheet of material 314 in the y-direction where the biased tensioner 336 and the second roller 332 retain the sheet of material 314 in tension in the y-direction.

[0093] The biased tensioner 336 is similarly constructed as the biased tensioner 322 and include a rigid member 331 with an arcuate surface 329. An end 313 of the second sheet of material 314 is positioned about the arcuate surface 329 and into a recess 333 in the rigid member 331 . A retaining strap 335 is positioned over the end 313 of the second sheet of material 314. Thesecond sheet of material 314 is placed into tension proximate the end 313, and a plurality of bolts 337 engage threaded bores in the rigid member 331, such that the plurality threaded bolts 337 frictionally retain the end 313 in tension between the rigid member 331 and the retaining strap 335.

[0094] The biased tensioner 336 engages stationary members 338 and 340 that are non- movably secured to the X-bridge 60 proximate ends of the rigid member 331. Compression springs 342 and 344 are positioned into cavities in the stationary members 338 and 340 and the rigid member 331 away from the second roller 332 in the x direction such that tension is retained on the second sheet of material 314. The biased tensioner 336 aids in keeping the second sheet of material 314 taut as the diameter of the material on the second roller 314 changes as the tool tray 201 is moved in the x direction.

[0095] The first and second rollers 316 and 332 are timed to rotate relative to each other about axles 346 and 348. Gears 354 and 356 are non-rotatably attached to the axles 346 and 348 and a timing belt 358 couples the gears 354 and 356 and causes both the first and second rollers 316 and 332 to rotate as the tool tray 201 moves in the x-direction. The x direction thermal isolator 310 includes a tensioner 360 that engages the timing belt 358 such that the timing belt 358 remains in tension and prevents the gears 354 and 356 from slipping as the timing belt 358 is driven by the movement the x-y gantry 28 in the x direction

[0096] The sheets of material 312 and 314 can be held with a consistent amount of tension, in order to hold the sheets of material 312 and 314 substantially flat against the X-bridge 60, and to ensure that heat from the heated build chamber 16 does not escape upward into the tool chamber, as the print head 24 is moved in the x-direction by the x-y gantry 28 about the 3D printer 10. The x-direction thermal isolator 310 includes a first brush 311 proximate the first roller 316 and a second brush 313 proximate the second roller 332. The first brush 311 engages the sheet of material 312 and forces the sheet of material 312 into contact with the X-bridge 60. The second brush 313 engages the sheet of material 314 and also forces the sheet of material 314 into contact with the X-bridge 60. An exemplary and non-limiting material for the brushes 311 and 313 includes nylon bristles. However, a roller having a low friction plastic coating could also be used to direct the sheets of material 312 and 314 into contact with the X-bridge 60 to minimize heat loss from the heated build chamber 16 into the tool chamber 18.

[0097] By maintain compliance or tension with the biased tensioners 322 and 336, the sheets of material 312 and 314 can be wound tightly onto the first and second rollers 316 and 332. Asone roller unrolls fabric and the other roller rolls up fabric, the diameters of the material on the first and second rollers 316 and 332 begin to differ. Having the biased tensioners 322 and 336, allows the two rollers to unroll and roll in a synchronized fashion when the diameters change, while maintaining consistent tension of the overall extended portion of the belt. By way of example, as a diameter of material on the roller gets larger, the linear length of fabric rolled up per rotation increases with the other roller’s fabric diameter decreases the length of material per rotation. Utilizing the biased tensioners 322 and 336 aids in compensating for the ever-changing diameters of fabric on the rollers 316 and 318.

[0098] As the XY gantry 28 moves the tray 201 causing the sheet of material to be unrolled off one roller. The unrolling of the sheet of material from one roller drives the timing belt 258 which in turn causes the other sheet of material to be rolled onto the other roller. When the direction of movement of the XY gantry 28 in the x-direction is reversed, the tray 201 moves which causes the sheet of material to be unwound from the other roller. The rotation of the other roller causes the timing belt 258 to reverse rotational direction which drives the first roller and causes material to be rolled thereon.

[0099] Referring to FIGS. 16-18, the movement of the tray 201 from one side to another side of the X-bridge 60 is illustrated along with the effects on the diameters on the rollers 316 and 318 and the biased tensioners 322 and 336. Referring to FIG. 16, the tray 201 is positioned proximate one end of the X-bridge 60 where the diameter DI of the roller 316 is larger than the diameter D2 of the roller 318. With the diameter DI of the roller 316 being larger that the diameter D2 of the roller 318, a rotation of the roller 316 will coil or unwind more linear length of fabric than a rotation of the roller 318. The biased tensioners 322 and 336 compensate of the difference in linear length per rotation to or from the rollers 316 and 318. A distance LI between the stationary member 324 and the rigid member 321 of the biased tensioner 322 is negligible with the tray 201 at the end of the X-bridge 60 while the distance L2 between the stationary member 328 and the rigid member 331 of the biased tensioner 336 compensates for the differences in linear length of rotation between the rollers 316 and 318 such that total lineal lengths per rotation with compensation from the biased tensioners 322 and 336 maintain the sheets of material 312 and 314 in tension.

[0100] Referring to FIG. 17, the tray 201 is substantially centrally located on the X-bridge 60. With the tray 201 substantially centrally located on the X-bridge 60, the diameter DI on the roller 316 is substantially the same as the diameter D2 on the roller 318 and the distance LI between thestationary member 324 and the rigid member 321 of the biased tensioner 322 and the distance L2 between the stationary member 328 and the rigid member 331 of the biased tensioner 336 are substantially the same due to the fact that each rotation coils or releases about the same length of material from each roller 316 and 318.

[0101] Referring to FIG. 18, the other extreme position of the tray 201 on the X-bridge 60 is illustrated. In FIG. 18, the diameter DI of the roller 316 is smaller than the diameter D2 of the roller 318. With the diameter D2 of the roller 318 being larger that the diameter DI of the roller 316, a rotation of the roller 318 will coil or unwind more linear length of fabric than a rotation of the roller 316. A distance L2 between the stationary member 328 and the rigid member 331 of the biased tensioner 336 is negligible with the tray 201 at the end of the X-bridge 60 while the distance LI between the stationary member 323 and the rigid member 321 of the biased tensioner 322 compensates for the differences in linear length of rotation between the rollers 316 and 318 such that total lineal lengths per rotation with compensation from the bias tensioners 332 and 336 maintain the sheets of material 312 and 314 in tension.

[0102] Maintaining tension on the sheets of the material 312 and 314 in the x and y directions as the XY gantry 28 moves the tray 201 back and forth in the x direction retains the sheets of material to be substantially flat against the X-bridge 60, which prevents air leakage and the loss of thermal energy from the heated build chamber 16 upward into the unheated tool chamber. An exemplary material of construction for the first and second sheets is a PTFE coated fiberglass sheet. The PTFE coated fiberglass sheet is sufficiently thin and strong such that the effective diameters of on the first and second rollers 316 and 332 are within the margin of compensation by the biased tensioners 322 and 336. The sheets of material may include other fabric types or materials as long as it provides a similar thickness, amount of flexibility, and insulative capability. The sheets of material can also be capable of tolerating the raised temperatures of the heated build chamber, as well as being capable of rigorous movement. The sheets of material also are substantially abrasion resistant, and resist material degradation over time from repeated heat exposure.

[0103] Another embodiment of the x-direction roller isolator is illustrated at 380 in FIG. 9. The x-direction roller isolator utilizes the same X-bridge 60, tray 207 with the aperture 206, the first and second rollers 316 and 332, biased tensioners 322 and 336, the timing belt 358 and thetensioner 360. However, instead of utilizing two sheets of material 312 and 314 a single sheet of material 382 with ends wound or coiled onto the first and second rollers 316 and 332 is utilized.

[0104] The single sheet of material 382 pass around a first sheet path roller 384 having an axle385 retained to the rigid member 321 of the biased tensioner 322 such that the first sheet path roller 384 is moved by the biased tensioner 322 based upon the diameter of the roller 316. The single sheet of material 382 passes below the first sheet path roller 384 and is fixedly secured to a bottom surface of the tray 201 with any suitable attaching mechanism including rivets, bolt and adhesive. The single sheet of material 382 then passes about a second sheet path roller 386 having an axle 387 retained to the rigid member 331 of the biased tensioner 336 such that the second sheet path roller 386 is moved by the biased tensioner 336 based upon the diameter of the roller 332

[0105] The embodiment 380 works similar to that of the embodiment 310 where the XY gantry 28 drives the tray 201 in the direction of arrows 388 and 390, one roller takes up material and the other roller releases material and the biased tensioners 322 and 336 compensate for the difference in length per rotation of the rollers 316 and 332. The first and second sheet path rollers 384 and386 retain the single sheet of material 382 in tension in the y-direction such that the single sheet of material 382 is substantially flat against the X-bridge 60 as the tray 201 is moved back and forth in the direction of arrows 388 and 390 and retains heat within the heated build chamber 16.

[0106] Referring to FIGS. 12, 13, and 20-23, the y-direction roller isolator 400 includes a first roller 402 attached to the 3D printer proximate an edge of an opening between the heated build chamber 16 and the tool chamber 18 and spans the opening in the x-direction. The first roller 402 includes a first roll of material 403, where a free end is secured to a biased tensioner 406 that spans the length of the opening in the x-direction. The biased tensioner 406 similarly constructed to that of the biased tensioners 322 and 336. The biased tensioner 406 includes a rigid member 407 with an arcuate surface 405 and a recess that accepts an end 401 of the material 403 and is retained with bolts frictionally securing the end 401 between a strap 409 and the rigid member 405. Stationary members 408 and 410 are non-movably attached to the X-bridge 60 along the edges of the opening in the y-direction. Compression springs 411 and 413 are retained within cavities in the stationary members 408 and 410 and the rigid member 405 to bias the rigid member 405 away from the first roller 402. The biased tensioner 406 biases the first roll of material 403 into tension in the x- direction and the y-direction as material 403 is rolled and unrolled from the first roller 402. A rotational actuator 412, such as an electric motor, is attached to an axle 414 of the first roller 402to cause the first roller 402 to rotate as the XY gantry 28 moves the X-bridge 60 moves in the y- direction.

[0107] The y-direction roller isolator 400 includes a second roller 420 attached to the 3D printer proximate an edge of the opening that spans the opening in the x-direction. The second roller 420 includes a second roll of material 422, where a free end 424 is secured to a biased tensioner 426 (as partially illustrated in FIGS. 20-22) that spans the length of the opening in the x direction. The biased tensioner 426 has similar components as the biased tensioner 405 including the rigid member 425 with the arcuate surface 423 with a recess and strap 427 that secures the free end between the strap 427 and the rigid member 425 with bolts or other securing devices The biased tensioner 426 includes stationary members that are non-movably attached to the X-bridge 60 along the edges of the opening in the y-direction, where one stationary member is illustrated at 428. Compression springs 429 are retained in cavities in the stationary members 428 and cavities in the rigid member 425 and the second roll of material 422 into tension in the y-dircction while attachment of the free end 424 to the biased tensioner 426 maintains the roll of material 422 in tension in the x-direction. A rotational actuator 432 is attached to an axle 434 of the second roller 420 to cause the second roller 420 to rotate in a direction that is timed with the rotational speed of the first roller 402 as the XY gantry 28 moves the X-bridge 60 in the y-direction.

[0108] As the XY gantry 28 moves the X-bridge 60 in the y-direction, the rotational actuators 412 and 432 cause the first and second rollers 402 and 420 to rotate where one roller takes up material and the other roller releases material such that the material 403 and 422 is retained in tension by the biased tensioners 406 and 426. With the materials 403 and 422 in tension in the x and y directions as the X-bridge 60 moves in the y-direction, the materials 403 and 422 remain substantially flat along the opening and prevents the leakage of heated air from the heated build chamber 16.

[0109] The rotation of the first and second roller 402 and 420 is control by the controller assembly 38. Encoders 413 and 433 sense the rotation of the rotational actuators 412 and 432 and provide feedback to the control assembly 38. While encoders 413 and 433 are described, other sensing devices are within the scope of the present disclosure including, but not limited to, transducers. The control assembly 38 and the rotational actuators 412 and 432 can be utilized to rotate the first and second rollers 402 and 420 at different rotational speeds to aid in compensatingfor diametrical changes in each roller as the roller sheets are rolled and unrolled from the first and second rollers 402 and 420.

[0110] Referring to FIGS. 20-22, the movement of the y-direction roller isolator 400 with the changing diameters of the rollers 402 and 420 along with the movements of the biased tensioners 406 and 426 that compensate for the changing lineal length of material rolled and unrolled per revolution of the rollers 402 and 420 due to the changing diameters. FIG. 20 illustrates the X- bridge proximate the roller 402 such that the diameter D3 of the roller 402 is larger than a diameter D4 of the roller 420. With D3 larger than D4, the biased tensioners 406 and 426 compensate for the difference in the lineal length of material per revolution where the distance L3 between the stationary member 408 and the rigid member 407 is substantially nil and the distance L4 between the stationary member 428 and the rigid member 425 compensate for the difference in lineal length per revolution of the rollers 402 and 420.

[0111] FIG. 21 illustrates the X-bridgc 60 substantially midway between the roller 402 and the roller 420, such that the diameters D3 and D4, respective, arc substantially the same. With D3 and D4 substantially the same, the distance L3 between the stationary member 408 and the rigid member 407 of the biased tensioner 406 is substantially the same as the distance L4 between the stationary member 428 and the rigid member 425 of the biased tensioner 426.

[0112] FIG. 22 illustrated the X-bridge 60 located proximate the roller 420 such that the diameter D4 of the roller 420 is larger than a diameter D3 of the roller 402. With D4 larger than D3, the biased tensioners 406 and 426 compensate for the difference in the lineal length of material per revolution where the distance L4 between the stationary member 428 and the rigid member 425 is substantially nil and the distance L3 between the stationary member 408 and the rigid member 407 compensate for the difference in lineal length per revolution of the rollers 402 and 420.

[0113] Referring to FIGS. 23-25, another y-direction roller isolator is illustrated at 500 with the x-direction roller isolator 380 within the X-bridge 60, as previously described. The y-direction roller isolator 500 includes a first roller 510 with a first roll of material 512 that spans to one side 59 of the X-bridge 60 and a second roller 520 with a second roll of material 522 that spans to another side 61 of the X-bridge 60 such that y-direction roller isolator 500 spans the opening and accommodates movement of the X-bridge 60 during the printing process.

[0114] The y-direction thermal isolator 500 includes a first idler roller 514 that is rotatably connected to the X-bridge 60 proximate the side 59 wherein the first roll of material 512 is positioned about the first idler roller 514. The first roll of material 512 is directed below the first idler roller 514 a selected distance above the frame defining the opening of the build envelope and back to a biased tensioner 530 attached to the frame proximate and below the first roller 512.

[0115] The biased tensioner 530 is similarly constructed as the prior bias tensioners 406 and 426. The biased tensioner 530 includes a rigid member 532 that spans the opening in the x- direction where the rigid member 532 includes an arcuate surface 534 and a recess 536. An end 516 of the first roll of material 512 is positioned about the arcuate surface 534 and into the recess 536 where a strap 538 is posited over the end 516 and frictionally retained to the rigid member 532 with a plurality of bolts or other securing mechanisms. The biased tensioner 530 includes stationary members located on the frame on opposing edges, one of which is illustrated at 540. Compression springs, one of which is illustrated at 542, arc positioned into cavities in the stationary members, one of which is illustrated at 542 and into cavities in the rigid member 532 such that the rigid member 532 is biased away from the stationary members 542.

[0116] The y-direction thermal isolator 500 includes a second idler roller 524 that is rotatably connected to the X-bridge 60 proximate the side 61 wherein the second roll of material 522 is positioned about the second idler roller 524. The second roll of material 522 is directed below the second idler roller 524 a selected distance above the frame defining the opening of the build envelope and back to a biased tensioner 550 attached to the frame proximate and below the first roller 522.

[0117] The biased tensioner 550 is similarly constructed as the prior bias tensioners 406, 426 and 530. The biased tensioner 550 includes a rigid member 552 that spans the opening in the x- direction where the rigid member 552 includes an arcuate surface 554 and a recess 556. An end 526 of the second roll of material 522 is positioned about the arcuate surface 554 and into the recess 556 where a strap 558 is posited over the end 526 and frictionally retained to the rigid member 552 with a plurality of bolts or other securing mechanisms. The biased tensioner 550 includes stationary members located on the frame on opposing edges, one of which is illustrated at 560. Compression springs, one of which is illustrated at 562, are positioned into cavities in the stationary members, one of which is illustrated at 560 and into cavities in the rigid member 552 such that the rigid member 552 is biased away from the stationary members 560.

[0118] A rotational actuator 570, such as an electric motor, is attached to an axle 511 of the first roller 510 to cause the first roller 510 to rotate as the XY gantry 28 moves the X-bridge 60 moves in the y-direction. A rotational actuator 580 is attached to an axle 521 of the second roller 520 to cause the second roller 520 to rotate in a direction that is timed with the rotational speed of the first roller 510 as the XY gantry 28 moves the X-bridge 60 in the y-direction.

[0119] As the XY gantry 28 moves the X-bridge 60 in the y-direction, the rotational actuators 560 and 570 cause the first and second rollers 510 and 520 to rotate where one roller takes up material and the other roller releases material such that the material 512 and 522 is retained in tension by the biased tensioners 530 and 550. With the materials 512 and 522 in tension in the x and y directions as the X-bridge 60 moves in the y-direction, the materials 512 and 522 remain substantially flat along gaskets 590 extending along opposing lengths of the opening in the ndirection and prevents the leakage of heated air from the heated build chamber 16.

[0120] The rotation of the first and second rollers 510 and 520 is control by the controller assembly 38. Encoders 572 and 582 sense the rotation of the rotational actuators 570 and 580 and provide feedback to the control assembly 38. While encoders 572 and 582 are described, other sensing devices are within the scope of the present disclosure including, but not limited to, transducers. The control assembly 38 and the rotational actuators 570 and 580 can be utilized to rotate the first and second rollers 510 and 520 at different rotational speeds to aid in compensating for diametrical changes in each roller as the roller sheets are rolled and unrolled from the first and second rollers 510 and 520 while the biasing tensioners 530 and 550 also aid in compensating for the differences in diameter on the rollers 510 and 520.

[0121] Referring to FIGS. 26-28, the movement of the y-direction roller isolator 500 with the changing diameters of the rollers 510 and 520 along with the movements of the biased tensioners 530 and 550 that compensate for the changing lineal length of material rolled and unrolled per revolution of the rollers 510 and 520 due to the changing diameters. FIG. 20 illustrates the X- bridge 60 proximate the roller 510 such that the diameter D5 of the roller 510 is larger than a diameter D6 of the roller 520. With D5 larger than D6, the biased tensioners 530 and 550 compensate for the difference in the lineal length of material per revolution where the distance E5 between the stationary member 540 and the rigid member 532 is substantially nil and the distance E6 between the stationary member 560 and the rigid member 552 compensate for the difference in lineal length per revolution of the rollers 510 and 520.

[0122] FIG. 27 illustrates the X-bridge 60 substantially midway between the roller 510 and the roller 520, such that the diameters D5 and D6, respective, are substantially the same. With D5 and D6 substantially the same, the distance L5 between the stationary member 540 and the rigid member 532 of the biased tensioner 530 is substantially the same as the distance L6 between the stationary member 560 and the rigid member 552 of the biased tensioner 550.

[0123] FIG. 28 illustrated the X-bridge 60 located proximate the roller 520 such that the diameter D6 of the roller 520 is larger than a diameter D5 of the roller 510. With D6 larger than D5, the biased tensioners 530 and 550 compensate for the difference in the lineal length of material per revolution where the distance L6 between the stationary member 560 and the rigid member 552 is substantially nil and the distance L5 between the stationary member 540 and the rigid member 532 compensate for the difference in lineal length per revolution of the rollers 510 and 520.

[0124] The y-dircction roller isolator 500 having the upper and lower segments of material on each side of the X-bridge 60 can provide benefits that a single layer roller isolator may not be able to provide. One benefit is additional insulation in an air gap 592 and 594 between the upper and lower segments of material 512 and 522. The air gap 592 and 594 prevent heat from entering into the tool chamber 18.

[0125] Additionally, as the X-bridge 60 moves, the material 512 and 522 contacting the gasket 590 is place and lifted from the gasket 590. Placing and lifting the material 512 and 522 onto and from the gasket 590 extends the life of the gasket 590 relative to sliding the material on the gasket 590.EXAMPLES

[0126] The present disclosure is more particularly described in the following examples that are intended as illustrations only, since numerous modifications and variations within the scope of the present disclosure will be apparent to those skilled in the art.Example 1 - Pleated (prior art) thermal isolator vs. roller thermal isolator

[0127] A comparison of open space between the roller thermal isolator relative of the present disclosure relative to the prior art accordion pleated bellows is provided herein on a 3D printer with an opening between the heated print chamber and the tool chamber of about 1 ,200 in2havinga x-direction length of about 30 in and a y-direction length of about 40 in. The accordion pleated bellows includes a x-direction bellows in x-bridge and a y-direction bellows on opposite sides of the x-bridge.

[0128] The x-direction accordion bellows is single pleated and has about 41.4 in2of cross sectional area of leakage, which includes a 0.125 inch gap on each end. The formula used to calculate the cross-sectional area of leakage is as follows:AreaXLeak (in2) = 1.38*X travel (in) (Equation 1)

[0129] With Xtravel about 30 in. results in 41.4 in2cross-sectional area of leakage.

[0130] The volume in in3is calculated by the following formulaVolumcXLcak (in3) -■ ArcaXLcak(in2)* 0.25 (Equation 2)

[0131] Using Equation 2 with an AreaX Leak value of 41.4 in2results in a calculation of about 10.35 in3in leak volume in the x-direction bellows.

[0132] The y-direction accordion bellows is double pleated, but is significantly more expensive than a single pleated accordion bellows. The y-direction accordion bellows leak area is calculated by the following equation:Area Y Leak in2= 0.855*Ytravel(in) (Equation 3)

[0133] With a Y travel of about 40 in, AreaYleak is calculated to be about 34 in2accounting for the 0.125 in gaps at each end of the y-bellows, the area of leakage correlates to about 8.5 in3in leak volume by the following equation:Volume YLeak (in3) = AreaYLeak(in2)* 0.25 (Equation 4)

[0134] The total calculated leak in a typical accordion pleated bellows is about 75.4 in2which calculates to a total leak volume of 18.85 in3. This amount of open leakage can adversely affect equipment above the heated build chamber when oven temperatures exceed 200 °C.

[0135] The thermal roller isolator of the present disclosure does not depend upon the length of travel of the x-direction roller isolator or the y-direction roller isolator because the x and y direction roller isolators are retained substantially flat as the XY gantry moves the tool. The x area leak is about 0.5 in2and the y area leak is about 1 / 5 in2. Using Equation 2 and 4, the VolumeXLeak is calculated to be about 0.125 in3and the Volume YLeak is calculated to be about 0.375 in3.The total area leakage is about 2 in2with a total volume leakage of about 0.5 in2.

[0136] Based upon the above calculations, the disclosed thermal roller isolator has about 73.4 in2 less air leakage based upon open area and about 18.35 in3reduction in air leak volume. This results in about a 97% reduction in leakage area and about a 97% reduction in leakage volume relative to a prior art accordion pleated bellows barrier.Example 2 - Overlapping Flaps (prior art) vs. Side Comer Beam seal insulation

[0137] A comparison of open areas (areas for heat leakage out of the heated chamber) between the side corner beam seals of the present disclosure and the prior art overlapping flaps of material was determined in this example. In the example, the beam is about 1 in. in thickness across the slot.

[0138] Referring to FIG. 29, the prior art overlapping flap seal is illustrated at 600 that spans a slot 602 in a wall of a heated build chamber 604. The overlapping flap seal 600 include left and right flaps 606 and 608 that overlap to form a slit 610 through which a beam 612 is positioned. The thickness of the beam 612 creates open areas 614 and 616 above and below the beam 612. The area of the openings 614 and 616 approximated a 1 in x 9 in triangular opening. The area of each opening was calculated by the formulaArea Triangle = 0.5 base x height (Equation 5)

[0139] This calculates to an open area of 4.5 in2for each opening 614 and 616, totaling about 9.0 in2for each slot. When accounting for four beams, the total open area around the beams results in about 36.0 in2through which heated air can escape.

[0140] In contrast, the seal illustrated in FIGS. 6-8 has an estimated opening of about 0.16 in2in total about all four beams. This results in a reduction in open space around the beams of about35.84 in2or about a 99% decrease in area where air can easily escape from the heated build chamber.

[0141] Although the present disclosure may have been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the disclosure.

Claims

AMENDED CLAIMS received by the International Bureau on 11 February 2025 (11 .02.2025)1. An extrusion-based 3D printer (10) comprising: a heated build chamber (16); a gantry (28) configured to move one or more tools (24)within the heated build chamber (16)- a roller thermal isolator (300) positioned over an opening in a ceiling of the heated build chamber (16), the roller thermal isolator (300) comprising: a x-direction roller isolator (380) comprising: a tray (201) spanning the opening in the heated build chamber (16) in a y- direction, the tray (201) movable in the y direction, the tray (201 Comprising a tool port (206) within the tray (201), the tool port (206) movable in the x- direction; a first set of non-torsion rollers (316, 332) carried by the tray (201), each roller (316, 332) of the first set of non-torsion rollers (310) retaining a portion of a x-direction sheet (382) of the x-direction thermal isolator (380), wherein the x-direction sheet (382) of the thermal isolator (300) is held in tension in the x and y directions as the tray (201) moves in the x direction by compensating for changes in diameter of the first set of rollers (315, 332); and a y-direction roller isolator (400) comprising: a second set of non-torsion rollers, each of the second set of non-torsion rollers (402, 420) located at edges of the opening and spanning the opening in the x direction, each of the second set of rollers (402, 420) retaining a portion of a y direction sheet (403, 422) of the y- direction thermal isolator (400), wherein the y direction sheet (403, 420) of the y-direction thermal isolator (400) is held in tension in the x and y directions as the tray (201) moves in the y direction.

2. The extrusion-based 3D printer of claim 1, wherein the x-direction roller isolator comprises: a first non-torsion roller of the first set of rollers attached to the tool port movable in the tray, the first roller biased to rotate in a first rotational direction; a first sheet of material wound on the first non-torsion roller, the first sheet of material having a first free end; a first x-direction biased tensioner comprising: a first retaining mechanism secured to the first sheet of material, the first retaining mechanism configured to retain the first sheet of material in tension in the y direction; and spaced apart first biasing mechanisms attached to the tray, wherein the spaced apart first biasing mechanisms engage the first retaining mechanism and retain the first sheet of material in tension in the x direction as the tool port moves in the x direction; a second non-torsion roller of the first set of rollers attached to the tool port movable in the tray a distance from the first roller, the second roller biased to rotate in a second rotational direction opposite the first rotational direction of the first roller; a second sheet of material wound on the second roller, the second sheet of material having a second free end; and a second x-direction biased tensioner comprising: a second retaining mechanism secured to the second sheet of material, the second retaining mechanism configured to retain the second sheet of material in tension in the y direction; and spaced apart second biasing mechanisms attached to the tray, wherein the spaced apart second biasing mechanisms engage the second retaining mechanism and retain the second sheet of material in tension in the x direction as the tool tray moves in the x direction by compensating for changes in diameter of the second set of rollers.

3. The extrusion-based 3D printer of claim 1, wherein the x-direction roller isolator comprises:a first non-torsion roller of the first set of non-torsion rollers attached to the tool port movable in the tray; a second non-torsion roller of the second set of non-torsion rollers attached to the tool port movable in the tray a distance from the first non-torsion roller; a first free end of a sheet of material wound onto the first roller and a second free end of the sheet of material wound onto the second roller; a first guide roller moveably secured to the tray proximate an edge thereof; a second guide roller moveably secured to the tray proximate an opposite end thereof, the sheet of material is positioned about the first and second guide roller and is attached to the tool tray; and spaced apart first second sets of biasing mechanisms attached to the tray, wherein the spaced apart first and second biasing mechanisms engage the first and second guide rollers and retain the sheet of material in tension in the x direction as the tool tray moves in the x direction, wherein overlapping sheets of material provide insulation above the heated build chamber.

4. The extrusion-based 3D printer of claim 1 , where each roller of the first set of non-torsion rollers comprises: an axle; and a gear non-rotatably attached to the axle.

5. The extrusion-based 3D printer of claim 4 and further comprising: a timing belt engaging each gear, and configured to synchronize a rotation of the first and second non-torsion rollers; and a tensioner configured to engage and maintain tension on the timing belt.

6. The extrusion-based 3D printer of claim 1 , wherein the x direction sheet and the y direction sheet each comprises polytetrafluoroethylene coated fiberglass, silicone coated silica, silicone coated fiberglass, Kevlar®-glass textile, and / or aluminized fabric.

7. The extrusion-based 3D printer of claim 1, wherein the y-direction roller isolator comprises: a first y-direction sheet rolled onto a first y-direction non-torsion roller of the second set of non-torsion rollers, the first y-direction sheet having a free end; a first y-direction biased tensioner comprising: a first y-direction retaining mechanism engaging the first y-direction sheet in the x- direction proximate the free end and retaining the first y-direction sheet in tension in the x direction; spaced apart first y-direction biasing mechanisms secured to the tray, the spaced apart first y-direction biasing mechanisms engaging the first y-direction retaining mechanism and maintaining the first y-direction sheet in tension as the first y-direction non-torsion roller rotates as the tray moves in the y- direction; a second y-direction sheet rolled onto a second y-direction non-torsion roller of the second set of non-torsion rollers, the second y-direction sheet having a free end; a second y-direction biased tensioner comprising: a second y-direction retaining mechanism engaging the second y-direction sheet proximate the free end in the x-direction and retaining the second y- direction sheet in tension in the x-direction; and spaced apart second y-direction biasing mechanisms secured to the tray, the spaced apart second y-direction biasing mechanisms engaging the second y- direction retaining mechanism and maintaining the second y-direction sheet in tension as the second y-direction roller rotates as the tray moves in the y- direction.

8. The extrusion-based 3D printer of claim 7, a further comprising: a first rotational actuator coupled to the first y-direction non-torsion roller; and a second rotational actuator coupled to the second y-direction non-torsion roller, wherein the movement of the first and second rotational actuators are coordinated to maintain tension in the first and second y-direction sheets in the y- direction as the tray is moved in the y-direction.

9. The extrusion-based 3D printer of claim 8, wherein the first and second rotational actuators each comprise electric motors.

10. The extrusion-based 3D printer of claim 9 and further comprising first and second sensors configured to monitor rotations of the first and second electric motors.

11. The extrusion-based 3D printer of claim 10, wherein each of the first and second sensors comprises encoders.

12. The extrusion-based 3D printer of claim 1, wherein y direction sheet of the y-direction roller isolator comprises: a first y-direction sheet rolled onto a first y-direction non-torsion roller of the second set of non-torsion rollers, the first y-direction sheet having a free end; a first idler roller rotatably attached to the tray wherein the first y-direction sheet is positioned about the first idler roller; a first y-direction biased tensioner comprising: a first y-direction retaining mechanism engaging the first y-direction sheet in the x- direction proximate the free end and retaining the first y-direction sheet in tension in the x direction; spaced apart first y-direction biasing mechanisms secured to the frame proximate the first y-direction roller, the spaced apart first y-direction biasing mechanisms engaging the first y-direction retaining mechanism and maintaining the first y-direction sheet in tension as the first y-direction nontorsion roller rotates as the tray moves in the y-direction; a second y-direction sheet rolled onto a second y-direction non-torsion roller of the second set of non-torsion rollers, the second y-direction sheet having a free end; a second idler roller rotatably attached to the tray wherein the second y-direction sheet is positioned about the second idler roller; a second y-direction biased tensioner comprising:a second y-direction retaining mechanism engaging the second y-direction sheet proximate the free end in the x-direction and retaining the second y- direction sheet in tension in the x-direction; and spaced apart second y-direction biasing mechanisms secured to the frame proximate the second y-direction roller, the spaced apart second y-direction biasing mechanisms engaging the second y-direction retaining mechanism and maintaining the second y-direction sheet in tension as the second y- direction non-torsion roller rotates as the tray moves in the y-direction wherein the configuration of the first and second y-directional rollers aid in retain heat in the heated build chamber, wherein overlapping portions of the first and second y-direction sheets provide insulation above the heated build chamber.

13. The extrusion-based 3D printer of claim 12, a further comprising: a first rotational actuator coupled to the first y-direction roller; and a second rotational actuator coupled to the second y-direction roller, wherein the movement of the first and second rotational actuators are coordinated to maintain tension in the first and second y-direction sheets in the y- direction as the tray is moved in the y-direction.

14. The extrusion-based 3D printer of claim 13, wherein the first and second rotational actuators each comprise electric motors.

15. The extrusion-based 3D printer of claim 12 and further comprising first and second sensors configured to monitor rotations of the first and second electric motors.

16. The extrusion-based 3D printer of claim 15, wherein each of the first and second sensors comprises encoders.

17. The extrusion-based 3D printer of claim 12 and further comprising gaskets attached to the frame proximate the opining in the y-direction, wherein first and second y-direction sheets engage the gasket to aid in retaining heat within the heated build chamber.

18. A roller thermal isolator (300) configured to cover an opening in a heated build chamber (16) of a 3D printer (10) that allows for movement of a tool (24) in the heated build chamber (16), the roller thermal isolator (300) comprising: a tray (201) spanning the opening between the heated build chamber (16) and a tool chamber (18) in a y-direction, the tray movable in the y direction, the tray (201) comprising a tool port (206) within the tray(201), the tool port (206) movable in the x- direction; a x-direction roller isolator (380) comprising: a first set of non-torsion rollers (316, 332), each non-torsion roller (316, 332) of the first set of non-torsion rollers (316, 332) retaining a portion of a x- direction sheet (382) of the x-direction thermal isolator (380), wherein the x-direction sheet (382) of the x-direction thermal isolator (380) is held in tension in the x and y directions as the tray (201) moves in the x direction by compensating for changes in diameter of the first set of non-torsion rollers (316, 332); and a y-direction roller isolator (400) comprising: a second set of non-torsion rollers (402, 420), each of the second set of non- torsion rollers (402, 420) located at edges of the opening and spanning the opening in the x direction, each of the second set of rollers (402, 420) retaining a portion of a y direction sheet (403, 422) of the y-direction thermal isolator, wherein free ends of the y direction portions of the thermal isolator (402, 422) are held in tension in the x and y directions by compensating for changes in diameter of the second set of rollers as the tray (201) moves in the y direction.

19. The roller thermal isolator of claim 18, wherein the x-direction roller isolator comprises:a first non-torsion roller of the first set of non-torsion rollers attached to the tool port, the first non-torsion roller biased to rotate in a first rotational direction; a first sheet of material wound on the first non-torsion roller, the first sheet of material having a first free end; a first x-direction biased tensioner comprising: a first retaining mechanism secured to the first sheet of material, the first retaining mechanism configured to retain the first sheet of material in tension in the y direction; and spaced apart first biasing mechanisms attached to the tray, wherein the spaced apart first biasing mechanisms engage the first retaining mechanism and retain the first sheet of material in tension in the x direction as the tool port moves in the x direction; a second non-torsion roller of the second set of non-torsion rollers attached to the tool port a distance from the first roller, the second non-torsion roller biased to rotate in a second rotational direction opposite the first rotational direction of the first non- torsion roller; a second sheet of material wound on the second non-torsion roller, the second sheet of material having a second free end; and a second x-direction biased tensioner comprising: a second retaining mechanism secured to the second sheet of material, the second retaining mechanism configured to retain the second sheet of material in tension in the y direction; and spaced apart second biasing mechanisms attached to the tray, wherein the spaced apart second biasing mechanisms engage the second retaining mechanism and retain the second sheet of material in tension in the x direction as the tool tray moves in the x direction.

20. The roller thermal isolator of claim 18, wherein the x-direction non-torsion roller isolator comprises: a first non-torsion roller of the first set of non-torsion rollers attached to the tool port, the first non-torsion roller;a second non-torsion roller of the first set of non-torsion rollers attached to the tool port a distance from the first non-torsion roller; a first free end of a sheet of material wound onto the first non-torsion roller and a second free end of the sheet of material wound onto the second non-torsion roller; a first guide roller moveably secured to the tray proximate an edge thereof; a second guide roller moveably secured to the tray proximate an opposite end thereof, the sheet of material is positioned about the first and second guide roller and is attached to the tool tray; and spaced apart first second sets of biasing mechanisms attached to the tray, wherein the spaced apart first and second biasing mechanisms engage the first and second guide rollers and retain the sheet of material in tension in the x direction as the tool tray moves in the x direction wherein overlapping portions of the sheet of material provide insulation above the heated build chamber.

21. The roller thermal isolator of claim 19, where each non-torsion roller of the first set of nontorsion rollers comprises: an axle; and a gear non-rotatably attached to the axle.

22. The roller thermal isolator of claim 21 and further comprising: a timing belt attached to each gear; and a tensioner configured to engage and maintain tension on the timing belt and synchronize rotations of the first and second non-torsion rollers.

23. The roller thermal isolator of claim 18, wherein the y-direction non-torsion roller isolator comprises: a first y-direction sheet rolled onto a first y-direction non-torsion roller of the second set of rollers, the first y-direction sheet having a free end; a first y-direction biased tensioner comprising:a first y-direction retaining mechanism engaging the first y-direction sheet in the x- direction proximate the free end and retaining the first y-direction sheet in tension in the x direction; spaced apart first y-direction biasing mechanisms secured to the tray, the spaced apart first y-direction biasing mechanisms engaging the first y-direction retaining mechanism and maintaining the first y-direction sheet in tension as the first y-direction non-torsion roller rotates as the tray moves in the y- direction; a second y-direction sheet rolled onto a second y-direction non-torsion roller of the second set of rollers, the second y-direction sheet having a free end; a second y-direction biased tensioner comprising: a second y-direction retaining mechanism engaging the second y-direction sheet proximate the free end in the x-direction and retaining the second y- direction sheet in tension in the x-direction; and spaced apart second y-direction biasing mechanisms secured to the tray, the spaced apart second y-direction biasing mechanisms engaging the second y- direction retaining mechanism and maintaining the second y-direction sheet in tension as the second y-direction roller rotates as the tray moves in the y- direction.

24. The roller thermal isolator of claim 23, a further comprising: a first rotational actuator coupled to the first y-direction non-torsion roller; and a second rotational actuator coupled to the second y-direction non-torsion roller, wherein the movement of the first and second rotational actuators are coordinated to maintain tension in the first and second y-direction sheets in the y- direction as the tray is moved in the y-direction.

25. The roller thermal isolator of claim 24 and further comprising first and second sensors configured to monitor rotations of the first and second electric motors.

26. The extrusion-based 3D printer of claim 18, wherein the y-direction roller isolator comprises: a first y-direction sheet rolled onto a first y-direction non-torsion roller of the second set of rollers, the first y-direction sheet having a free end; a first idler roller rotatably attached to the tray wherein the first y-direction sheet is positioned about the first idler roller; a first y-direction biased tensioner comprising: a first y-direction retaining mechanism engaging the first y-direction sheet in the x- direction proximate the free end and retaining the first y-direction sheet in tension in the x direction; spaced apart first y-direction biasing mechanisms secured to the frame proximate the first y-direction non-torsion roller, the spaced apart first y-direction biasing mechanisms engaging the first y-direction retaining mechanism and maintaining the first y-direction sheet in tension as the first y-direction roller rotates as the tray moves in the y-direction; a second y-direction sheet rolled onto a second y-direction non-torsion roller of the second set of rollers, the second y-direction sheet having a free end; a second idler roller rotatably attached to the tray wherein the second y-direction sheet is positioned about the second idler roller; a second y-direction biased tensioner comprising: a second y-direction retaining mechanism engaging the second y-direction sheet proximate the free end in the x-direction and retaining the second y- direction sheet in tension in the x-direction; and spaced apart second y-direction biasing mechanisms secured to the frame proximate the second y-direction roller, the spaced apart second y-direction biasing mechanisms engaging the second y-direction retaining mechanism and maintaining the second y-direction sheet in tension as the second y- direction non-torsion roller rotates as the tray moves in the y-direction.

27. The extrusion-based 3D printer of claim 26, a further comprising: a first rotational actuator coupled to the first y-direction roller; anda second rotational actuator coupled to the second y-direction non-torsion roller, wherein the movement of the first and second rotational actuators are coordinated to maintain tension in the first and second y-direction sheets in the y- direction as the tray is moved in the y-direction.

28. The extrusion-based 3D printer of claim 27, wherein the first and second rotational actuators each comprise electric motors.

29. The extrusion-based 3D printer of claim 28 and further comprising first and second sensors configured to monitor rotations of the first and second electric motors.

30. A method of retaining heat in a heated build chamber of a 3D printer, the method comprising: providing a non-torsion roller thermal isolator (300) between a heated build chamber (16) and a tool chamber (18), the roller thermal isolator (300) comprising: a tray (201) spanning the opening between the heated build chamber (16) and the tool chamber (18) in a y-direction, the tray (201) movable in the y direction, the tray (201) comprising a tool port (206) within the tray (201), the tool port (206) movable in the x- direction; a x-direction non-torsion roller (380) isolator comprising: a first set of non-torsion rollers (316, 332), each non-torsion roller of the first set of non-torsion rollers (316, 332) retaining a portion of a x- direction sheet (382) of the thermal isolator, wherein the x- direction sheet (382) of the thermal isolator (300) is held in tension in the x and y directions as the tray (201) moves in the x direction and the diameters of the first set of non-torsion rollers(316, 332) change; and a y-direction torsion roller (400) isolator comprising: a second set of non-torsion rollers (402, 420), each of the second set of non-torsion rollers (402, 420) located at edges of the opening and spanning the opening in the x direction, each of the second set ofnon-torsion rollers (402, 420) retaining a portion of a y direction sheet (403, 422) of the thermal isolator, wherein free ends of the y direction portions (403, 422) of the thermal isolator are connected to the tray (201) wherein the y direction sheet (403, 422) of the thermal isolator is held in tension in the x and y directions as the tray moves in the y direction and the diameters of the second set of non-torsion rollers change; positioning a portion of a tool (24) into the heated build chamber (16) through the tool port (206); moving the tool port (206) with the tool (24) in the x-direction wherein one non-torsion roller (316, 332) of the first set of non-torsion rollers unwinds a portion of the x- direction sheet (380) and another non-torsion roller (316, 332) of the first set of non-torsion rollers winds another portion of the x-direction sheet (380) thereon to maintain the x-direction sheet in tension; and moving the tray (206) in the y-direction wherein one non-torsion roller (402, 420) of the second set of non-torsion rollers unwinds a portion of the y-direction sheet (403, 422) and another non-torsion roller (402, 420) of the second set of non-torsion rollers winds another portion of the y-direction sheet (403, 422) thereon to maintain the y-direction sheet in tension.

31. The method of claim 30 and further comprising timing the rotation of the first set of non-torsion rollers with a timing belt.

32. The method of claim 30 and further comprising synchronizing the rotation of the second set of non-torsion rollers with first and second rotational actuators.

33. The method of claim 32 and further comprising monitoring the rotations of the first and second rotational actuators with first and second sensor.

34. The method of claim 30 and further comprising linearly moving locations of the second set of non-torsion rollers in the y direction as the tray moves in the y direction.

35. A 3D printer comprising: an enclosed build chamber (16) having a ceiling comprised of a y-axis deformable thermal insulator (400) and through which an active print (24) head accesses the build chamber (16) to print parts by extruding material onto a platen (3); an x-y gantry (28) mounted on top of the build chamber (16) and comprising an x -bridge (60) spanning the build chamber (16); a print head carriage (26) providing a tool mount (27) for removable installation of one or more print heads (24) and configured for back-and-forth movement along the x- bridge (60), wherein the x-y gantry (28)is configured to move the carriage in an x- y plane above the build chamber (16); an upward-facing tray (201) coupled to or integral with the carriage (26 )and having an open bottom providing a tool port (206) for accessing the heated build chamber (16); an x-axis deformable thermal insulator (300) spanning a length of the x -bridge (60) and coupled to opposite ends of the tray (201) and or the carriage (26) so as to expand and contract with the back-and-forth movement of the carriage (26) along the x- bridge (60), the x-axis deformable thermal insulator (300) thereby covering a portion of the build chamber (16) and forming part of the ceiling; and a thermal barrier (200) mounted in the tray (201)and covering the tool port and penetrable through an aperture (206) thereof, the aperture (206) providing an entry point to the build chamber (16) for the working end of the active print head (24), wherein when the working end is positioned though the aperture (206), the tool port (206) is substantially closed.

36. The 3D printer of claim 35, wherein the aperture has a geometry complimentary to a portion of a print head above the working end wherein the thermal barrier is configured to deform when the working end of the print head penetrates the thermal barrier and to return to a substantially- closed resting state thereafter and once the working end is removed from the aperture, the aperture contracts to limit the area through which heat can escape the heated build chamber.

37. The 3D printer of claim 35, wherein the y-axis deformable insulator comprises two components, each component coupled to the x-bridge on an opposite longitudinal edge thereof so as to expand and contract with movement of the x-bridge in a y-direction.38 The 3D printer of claim 36, wherein the x-axis deformable thermal insulator and the y-axis thermal insulators are each selected from a roller-style insulator and a baffle-style insulator.

39. The 3D printer of claim 35, wherein the thermal barrier comprises an elastic membrane and the aperture stretches and clings to a perimeter of the working end of the active print head.

40. The 3D printer of claim 35, wherein the aperture of the thermal barrier is perforated, having at least four substantially uniform spaced slits radially extending about a perimeter thereof.

41. The 3D printer of claim 39, wherein the thermal barrier has a layered construction.

42. The 3D printer of claim 35, wherein the thermal barrier comprises: a flexible and resilient middle portion having an upper surface and a lower surface with the central aperture; an upper layer of material adjacent the upper surface; and a lower layer of material adjacent the lower surface wherein the upper layer and the lower layer are joined by material extending about a perimeter of the aperture, wherein the material is configured to aid the working end of the active print head to pass through the aperture and prevent wear of the flexible and resilient middle portion.

43. The 3D printer of claim 42, wherein the flexible and resilient middle portion of the thermal barrier comprises substantially uniformly spaced slits radially extend from the aperture into the middle portion.

44. The 3D printer of claim 42, wherein the upper layer of material and the lower layer of material the thermal barrier includes a plurality of discrete units that are adjacent each other andallows portion between the slits of the flexible and resilient middle portion to move as the tool is positioned through the aperture.

45. The 3D printer of claim 44, wherein the upper and lower layers of material are coated onto the upper and lower surface of the flexible and resilient middle portion.

46. The 3D printer of claim 35, wherein the aperture is substantially circular.

47. The 3D printer of claim 35, wherein the aperture is substantially polygonal.

48. The 3D printer of claim 35, wherein the thermal barrier is configured to be removably retained within the upward-facing tool tray.

49. The 3D printer of claim 48, and further comprising a clamping member configured to removably retain the thermal barrier within the upward-facing tool tray.

50. A method of swapping print heads during a build job in a 3D printer that extrudes material into a heated build chamber, the method comprising: providing an x-y gantry (28) mounted on top of the build chamber (16) and comprising a x -bridge (60) spanning the build chamber (16), a print head carriage (26) providing a tool mount (27) for removable installation of one or more print heads (24) and configured for back-and-forth movement along the x -bridge (60), wherein the x-y gantry (28) is configured to move the carriage (26) in an x-y plane above the build chamber (16), an upward-facing tool tray (201) coupled to or integral with the carriage (26) and having an open bottom providing a tool port (206) for accessing the heated build chamber (16), an x-direction deformable thermal insulator (300) spanning a length of the x -bridge and coupled to opposite ends of the tray (201) and or the carriage (26) so as to expand and contract with the back-and-forth movement of the carriage along the x -bridge (60), the x-direction deformable thermal insulator (300) thereby covering a portion of the build chamber (16) and forming part of the ceiling, wherein the x-direction thermal barrier (300) comprises an aperture (206)configured to expand as a working end of a first print head (24) passes therethrough and configured to contract about the print head (24) once the working end passes through the thermal barrier; moving the working end of the first print head (24) through the thermal barrier (300), thereby causing the tool port (206) to be substantially closed; and lifting the first print head (24) from the heated build chamber (16) by passing the working end through the thermal barrier (300) and once the working end is removed from the aperture (206) for a tool swap, the aperture (206) contracts to an area that is less than a maximum cross-sectional area of the working end.

51. The method of claim 50, and further comprising printing at least a portion of a 3D part with the first print head while the working end is within the heated build chamber.

52. The method of claim 50 and further comprising: swapping the first print head for a second print head; moving a working end of the second print head through the thermal barrier thereby causing the tool port to be substantially closed; and lifting the second print head from the heated build chamber by passing the working end through the thermal barrier and once the working end is removed from the aperture for a tool swap, the aperture contracts to an area that is less than a maximum cross- sectional area of the working end.

53. The method of claim 50, wherein providing the aperture within the thermal barrier comprises providing a multilayer thermal barrier having a flexible and resilient middle layer and upper and lower layers with low surface energy wherein the low surface energy material covers the aperture.

54. The method of claim 53, wherein the flexible and resilient middle portion of the thermal barrier comprises substantially uniformly spaced slits radially extend from the aperture into the middle portion.

55. The method of claim 53, wherein the upper layer of material and the lower layer of material the thermal barrier comprises a plurality of portions having seams that align with the slits such that the aperture is configured to expand as a working end of a first print head passes therethrough and return to the substantially contracted, relaxed configuration about the first print head after the working end has passed through the aperture.

56. The method of claim 55, wherein the upper and lower layers are coated onto upper and lower surface of the flexible and resilient middle portion.

57. An 3D printer comprising: a heated build chamber (16) with opposing side walls (15), wherein at least one of the opposing side walls (15) includes at least one slot (17) oriented in a z-direction; a platen (30) movable within the heated build chamber (16) in the z-direction, at least one support beam (109) extending from the platen (30), wherein the at least one support beam (109) extends through the at least one slot (17), the at least one support beam (109) comprising: a first beam (110) extending from the platen (30) to proximate the at least one slot (17); a second beam (120) coupled to the at least one actuator (122); and spaced apart first and second beam members (106, 108) positioned through the plurality of slots (17) and connecting the first beam (110) and the second beam (12); at least one actuator (122) mounted external to the heated build chamber (16), the at least one actuator (122) being operably coupled to an end of the at least one support beam (109) to move the support beam (109) in a z-direction and thereby move the platen (30) within the heated build chamber (16); and at least one insulating seal (100) being in the at least one slot, (17) the at least one insulating seal (100) comprising: a middle portion (130) that spans a length of the at least one slot (17) wherein the middle portion (130) is sized to be positioned between the spaced apart first and second beam members (106, 108); andfirst and second outer portions (140, 142) that are secured to the side walls (15) proximate edges of the at least one slot (17) along the length, wherein the first and second outer portions (140, 142) abut an outer edge of the middle portion (130) to form the spaced apart slits (144, 146) through which the spaced apart substantially first and second beam members (106, 108) move to move the platen (30), wherein the first and second outer portions (140, 142) are deformable to accommodate movement of the beam (106, 108) within the at least one insulating seal (100) while maintaining a seal with the at least one insulating seal.

58. The extrusion-based 3D printer of claim 57, wherein: the at least one support beam comprises a plurality of support beams extending from the platen; the at least one slot comprises a plurality of slots in the opposing side walls, wherein each of the plurality of support beams comprises spaced apart substantially flat portions that span each of the plurality of slots in the opposing side walls, thereby defining an open area between the spaced apart substantially flat portions; the at least one actuator comprises a plurality of actuators mounted external to the heated build chamber wherein each of the plurality of actuators is coupled to one of the plurality of support beams; and the at least one steal comprises a plurality of seals, each of the plurality of seals being positioned over each of the plurality of slots, wherein each of the plurality of seals have spaced apart slits that allow the platen to move with the plurality of actuators while maintaining a seal with each of the plurality of beams.

59. The extrusion-based 3D printer of claim 57, wherein the first and second outer portions each comprises: an interior deformable insulative material comprises high temperature silicone compounds, fluoro-elastomeric foam compounds and combinations thereof; anda cover over the interior deformable insulative material, the cover comprising a heat resistant, flexible material comprising fiberglass, PTFE coated fiberglass, braided or mesh steel with a low friction coating, PTFE sheeting or woven fabric fibers.

60. The extrusion-based 3D printer of claim 57, wherein the middle portion comprises: a support member attached to the side wall proximate a top edge and a bottom edge of the slot; and an insulating member attached to the support member, wherein the insulating member comprises high temperature silicone compounds, fluoro-elastomeric foam compounds and combinations thereof.

61. The extrusion-based 3D printer of claim 57, wherein the heated build chamber is configured to be heated to or above 200 °C.

62. The extrusion-based 3D printer of claim 57, wherein the first and second outer portions comprise a cross-sectional configuration comprising cylindrical, hemi-spherical, oval, rectangular and / or elliptical.

63. A 3D printer comprising: a heated build chamber (16) with opposing side walls (15), each of the opposing side walls (15) defining a plurality of spaced apart slots (17) oriented in a z direction; a platen (30) within the heated build chamber (16) and movable in the z direction, the platen (30) including a plurality of support beams (109) extending from the platen (30), wherein each of the plurality of support beams (109) comprises substantially flat spaced apart portions (106, 108) extending through one of the plurality of slots (17); a plurality of actuators (122) mounted external to the heated build chamber (16), each of the plurality of actuators (122) being coupled to one of the ends of the plurality of support beams (109) with a coupling device; anda plurality of insulating seals (100), each of the plurality of insulating seals (100) being positioned over one of the plurality of slots (17), each of the plurality of insulating seals (100) comprising: a middle portion (130) that spans a length of each of the plurality of slots (17) wherein the middle portion ( 130) is sized to be positioned between the spaced apart substantially flat portions (106, 108); and first and second outer portions (140, 142) that are secured to the side walls (15) proximate edges of the plurality of slots (17) along the length, wherein the first and second outer portions (140, 142) abut outer edge of the middle portion (130), thereby defining spaced apart slits (144, 146) through which the spaced apart substantially flat portions (106, 108) move to move the platen (30).

64. The 3D printer of claim 63, wherein each of the plurality of support beams comprises: a first beam extending from the platen to proximate one of the plurality of slots; a second beam coupled to one of the plurality of actuators; and first and second beam members positioned through the plurality of slots and connecting the first beam and the second beams.

65. The extrusion-based 3D printer of claim 63, wherein the middle portion comprises: a support member attached to the side wall proximate a top edge and a bottom edge of the slot; and an insulating member attached to the support member, wherein the insulating member comprises high temperature silicone compounds, fluoro-elastomeric foam compounds and combinations thereof.

66. The extrusion-based 3D printer of claim 63, wherein the first and second outer portions each comprise: an interior deformable insulative material comprises high temperature silicone compounds, fluoro-elastomeric foam compounds and combinations thereof; anda cover over the interior deformable insulative material, the cover comprising a heat resistant, flexible material comprising fiberglass, PTFE coated fiberglass, braided or mesh steel with a low friction coating, PTFE sheeting or woven fabric fibers.

67. The extrusion-based 3D printer of claim 63, wherein the first and second outer portions comprise cross-sectional configurations comprising cylindrical, hemi-spherical, oval, rectangular and / or elliptical.

68. The extrusion-based 3D printer of claim 63, wherein the first and second outer portions are deformable to accommodate movement of the spaced apart substantially flat portions of the beam within the seal.

69. A method of retaining heat while moving a platen within a heated build chamber of a 3D printer, the method comprising: providing a heated build chamber (16) with opposing side walls (15), wherein at least one of the opposing side walls (15) includes at least one slot (17) oriented in a z- direction the at least one slot (17) covered with at least one insulating seal (100) comprising a middle portion (130) that spans a length of the at least one slot (17) wherein the middle portion ( 130) is sized to be positioned between spaced apart first and second beam members (106, 108), and first and second outer portions (140, 142) that are secured to the side walls (15) proximate edges of the at least one slot (17) along the length, wherein the first and second outer portions (140, 142) abut an outer edge of the middle portion (130) to form the spaced apart slits (144, 146); providing a platen (30) movable within the heated build chamber (16) in the z-direction having at least one support beam (109) extending from the platen (30), the at least one support beam (109) comprising a first beam (110) extending from the platen (30) to proximate the at least one slot (17), a second beam (120) coupled to at least one actuator (122) mounted external to the heated build chamber (16) wherein and spaced apart first and second beam members (106, 108) positionedthrough the plurality of slots (17) and into the spaced apart slits (144, 146) and connect the first beam (110) and the second beam (120); and energizing the at least one actuator (122) to move the support beam (109) in a z-direction and thereby move the platen (30)within the heated build chamber (16) where the first and second outer portions (140, 142) deform as the first and second beam members (106, 108) move within the at least one insulating seal (100) while maintaining a seal with the at least one insulating seal (100).

70. The method of claim 69, wherein providing a heated build chamber comprises: providing a plurality of opposing walls, each of the opposing walls comprising a plurality of slots; and covering each of the plurality of slots with one of a plurality of insulating seals having a middle portion that spans a length of each of the plurality of slots wherein the middle portion is sized to be positioned between the spaced apart first and second beam members, and first and second outer portions that are secured to the side walls proximate edges of the at least one slot along the length, wherein the first and second outer portions abut an outer edge of the middle portion to form the spaced apart slits.

71. The method of claim 69, wherein providing the movable platen comprises providing the platen with a plurality of support beams, each of the plurality of support beams comprises the first beam extending from the platen to proximate the at least one slot, the second beam coupled to one of a plurality of actuators mounted external to the heated build chamber and spaced apart first and second beam members positioned through the plurality of slots and into the spaced apart slits and connect the first beam and the second beam.

72. The method of claim 69, wherein the first and second outer portions each comprises: an interior deformable insulative material comprises high temperature silicone compounds, fluoro-elastomeric foam compounds and combinations thereof; anda cover over the interior deformable insulative material, the cover comprising a heat resistant, flexible material comprising fiberglass, PTFE coated fiberglass, braided or mesh steel with a low friction coating, PTFE sheeting or woven fabric fibers.

73. The method of claim 69, wherein the middle portion comprises: a support member attached to the side wall proximate a top edge and a bottom edge of the slot; and an insulating member attached to the support member, wherein the insulating member comprises high temperature silicone compounds, fluoro-elastomeric foam compounds and combinations thereof.

74. The method of claim 69, and further comprising heating the heat build chamber to a temperature at or above 200 °C.

75. The method of claim 69, wherein the first and second outer portions comprise a cross- sectional configuration comprising cylindrical, hemi-spherical, oval, rectangular and / or elliptical.STATEMENT UNDER ARTICLE 19(1)Transmitted herewith are replacement pages 37-59, containing replacement claims 1 -2, 7, 18, 23, 26, 30, 33 - 75. No other claims have been changed.This communication is responsive to a written opinion issued on December 11 , 2024. In response to the issue raised in the written opinion, the claims have been amended as outlined in the written opinion.However, with respect to claim 39 (now claim 38) it is respectfully submitted a roller style baffle is not defined as being a particular construction in independent claim 35. As such, Applicant submits that claim 29 appears to be in proper form.

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