Patent Publication Number: US-2018036952-A1

Title: Multilayer extrusion method for material extrusion additive manufacturing

Description:
BACKGROUND 
     Additive Manufacturing (AM) is a new production technology that can transform the way all sorts of things are made. AM can make three-dimensional (3D) solid objects of virtually any shape from a digital model. Generally, this can be achieved by creating a digital model of a desired solid object with computer-aided design (CAD) modeling software and then slicing that virtual blueprint into very small digital cross-sections. These cross-sections can be formed or deposited in a sequential layering process in an AM machine to create the 3D object. AM can have many advantages, including dramatically reducing the time from design to prototyping to commercial product. Running design changes are possible. AM allows designers to imagine shapes that would be impossible to create through older techniques. Multiple parts can be built in a single assembly. No tooling is required. Minimal energy is needed to make these 3D solid objects. It also decreases the amount of waste and raw materials. Parts can be made lighter and more durable than their predecessors. AM can also facilitate production of extremely complex geometrical parts. AM also reduces the parts inventory for a business since parts can be quickly made on-demand and on-site. 
     Material Extrusion (a type of AM) can be used as a low capital forming process for producing plastic parts, and/or forming process for difficult geometries. Material Extrusion can involve an extrusion-based additive manufacturing system that is used to build a three-dimensional (3D) model from a digital representation of the 3D model in a layer-by-layer manner by selectively dispensing a flowable material through a nozzle or orifice. After the material is extruded, it can be deposited as a sequence of roads on a substrate in an x-y plane. The extruded modeling material can fuse to previously deposited modeling material, and solidify upon cooling. The position of the extrusion head relative to the substrate can then be incremented along a z-axis (perpendicular to the x-y plane), and the process can then be repeated to form a 3D model resembling the digital representation. 
     Material Extrusion can be used to make final production parts, fixtures, and molds as well as to make prototype models for a wide variety of products. However, the strength of the parts in the build direction can be limited by the bond strength and effective bonding surface area between subsequent layers of the build. These factors can be limited for two reasons. First, each layer can be a separate melt stream. Thus, comingling of the polymer chains of a new layer with those of the antecedent layer can be reduced. Secondly, because the previous layer could have cooled, cohesion between layers can rely on conduction of heat from the new layer and any inherent cohesive properties of the material for bonding to occur. Reduced cohesion between layers can also results in a stratified surface finish. 
     In the creation of AM parts, portions of the part can be supported by a separate support material. This support material can be separately formed, such as extruded and placed where the model material can benefit from a support structure (e.g., to hold the model material as it cools and solidifies). Once the AM process is complete, support material can be removed from the model to reveal the part. In the past, the removal of support material from the part included mechanical removal of the support. Such removal can scar or otherwise impair the quality of the model surface along the interface between the model and the support material. 
     Accordingly, a need exists for an enhanced AM process capable of producing parts with improved aesthetic qualities and structural properties, both with and without support materials. 
     BRIEF DESCRIPTION 
     One embodiment of the present invention is drawn to a method of forming a three dimensional object comprising: moving a first polymer material through a first feed channel of an extrusion die having multiple feed channels; moving a second material through a second feed channel of the extrusion die, wherein the second material comprises a solvent, a release agent, a coating or a second polymer material; forming a multilayered extrudate along an extrusion axis, wherein the multilayered extrudate comprises the first polymer material and the second material, and wherein the extrusion axis is parallel to the movement of the multilayered extrudate; depositing a multitude of layers of the multilayered extrudate in a preset pattern on a platform; and fusing the multitude of layers to form the three dimensional object. 
     Another embodiment of the present invention is drawn to an article of manufacture comprising: a three dimensional object comprising a part made from a first polymer material and a support made from the first polymer material wherein the part and the support are separated by a release agent. The above described and other features are exemplified by the following figures and detailed description. 
     The above described and other features are exemplified by the following figures and detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Refer now to the figures, which are exemplary embodiments, and wherein the like elements are numbered alike. 
         FIG. 1  is an illustration of a cross-section of an extrusion die which can form a multilayered extrudate including a first polymer material and a second material. 
         FIG. 2  is an illustration of a cross-section of an extrusion die which can form a multilayered extrudate including a first polymer material and a second material where the second material can include a second polymer material. 
         FIG. 3  is an illustration of a cross-section of an extrusion die which can form a multilayered extrudate including a first polymer material, a second material, and a second polymer material. 
         FIG. 4  is an illustration of a cross-section of a pattern of multilayered extrudate including a first polymer material and a second material deposited by an additive manufacturing device. 
         FIG. 5  is an illustration of a cross-section of a pattern of multilayered extrudate including a first polymer material and a second material deposited by an additive manufacturing device where the second material can include a solvent and a release agent. 
         FIG. 6  is an illustration of a cross-section of a pattern of multilayered extrudate deposited by an additive manufacturing device where the multilayered extrudate includes a first polymer material, a solvent, a second polymer material, a second solvent and a release agent. 
     
    
    
     DETAILED DESCRIPTION 
     Disclosed herein are additive manufacturing modeling methods and apparatus capable of producing parts with increased bonding between adjacent model layers, and alternatively, with decreased bonding between model and support material layer. Without being bound by theory, it is believed that the favorable results obtained herein, e.g., high strength three dimensional polymeric components can be achieved by controlling interfacial adhesion (positively for better performance and negatively for better support removal) can overcome some surface tension between layers and can result in cohesion which can enable improved surface quality of parts. Moreover, reduced cohesion between the model and the support material can ease support material removal and improve surface quality of parts along the interface between the model and support material. Accordingly, parts with superior mechanical and aesthetic properties can be manufactured. 
     The term “material extrusion additive manufacturing technique” as used in the present specification and claims means that the article of manufacture can be made by any additive manufacturing technique that makes a three-dimensional solid object of any shape by laying down material in layers from a thermoplastic material such as a monofilament, powder, or pellet from a digital model by selectively dispensing through a nozzle, orifice, or die. For example, the extruded material can be made by laying down a plastic filament that is unwound from a coil or is deposited from an extrusion head. These monofilament additive manufacturing techniques include fused deposition modeling and fused filament fabrication as well as other material extrusion technologies as defined by ASTM F2792-12a. 
     The terms “Fused Deposition Modeling” or “Fused Filament Fabrication” involves building a part or article layer-by-layer by heating thermoplastic material to a semi-liquid state and extruding it according to computer-controlled paths. Fused Deposition Modeling utilizes a modeling material and a support material. The modeling material includes the finished piece, and the support material includes scaffolding that can be mechanically removed, washed away or dissolved when the process is complete. The process involves depositing material to complete each layer before the base moves down the Z-axis and the next layer begins. 
     The material extrusion extruded material can be made from thermoplastic materials. Such materials can include polycarbonate (PC), acrylonitrile butadiene styrene (ABS), acrylic rubber, ethylene-vinyl acetate (EVA), ethylene vinyl alcohol (EVOH), liquid crystal polymer (LCP), methacrylate styrene butadiene (MBS), polyacetal (POM or acetal), polyacrylate and polymethacrylate (also known collectively as acrylics), polyacrylonitrile (PAN), polyamide (PA, also known as nylon), polyamide-imide (PAI), polyaryletherketone (PAEK), polybutadiene (PBD), polybutylene (PB), polyesters such as polybutylene terephthalate (PBT), polycaprolactone (PCL), polyethylene terephthalate (PET), polycyclohexylene dimethylene terephthalate (PCT), and polyhydroxyalkanoates (PHAs), polyketone (PK), polyolefins such as polyethylene (PE) and polypropylene (PP), fluorinated polyolefins such as polytetrafluoroethylene (PTFE) polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyetherimide (PEI), polyethersulfone (PES), polysulfone, polyimide (PI), polylactic acid (PLA), polymethylpentene (PMP), polyphenylene oxide (PPO), polyphenylene sulfide (PPS), polyphthalamide (PPA), polypropylene (PP), polystyrene (PS), polysulfone (PSU), polyphenylsulfone, polytrimethylene terephthalate (PTT), polyurethane (PU), styrene-acrylonitrile (SAN), or any combination comprising at least one of the foregoing. Polycarbonate blends with ABS, SAN, PBT, PET, PCT, PEI, PTFE, or combinations comprising at least one of the foregoing are of particular note to attain the balance of the desirable properties such as melt flow, impact and chemical resistance. The material extrusion extruded material can also include polycarbonate copolymers such as LEXAN XHT, DMX, HFD, EXL, or FST copolymers or other polycarbonate copolymers. The amount of these other thermoplastic materials can be from 0.1% to 85 wt. %, in other instances, from 1.0% to 50 wt. %, and in yet other instances, from 5% to 30 wt. %, based on the weight of the monofilament. 
     The term “polycarbonate” as used herein means a polymer or copolymer having repeating structural carbonate units of formula (1) 
     
       
         
         
             
             
         
       
     
     wherein at least 60 percent of the total number of R 1  groups are aromatic, or each R 1  contains at least one C 6-30  aromatic group. Specifically, each R 1  can be derived from a dihydroxy compound such as an aromatic dihydroxy compound of formula (2) or a bisphenol of formula (3). 
     
       
         
         
             
             
         
       
     
     In formula (2), each R h  is independently a halogen atom, for example bromine, a C 1-10  hydrocarbyl group such as a C 1-10  alkyl, a halogen-substituted C 1-10  alkyl, a C 6-10  aryl, or a halogen-substituted C 6-10  aryl, and n is 0 to 4. 
     In formula (3), R a  and R b  are each independently a halogen, C 1-12  alkoxy, or C 1-2  alkyl; and p and q are each independently integers of 0 to 4, such that when p or q is less than 4, the valence of each carbon of the ring is filled by hydrogen. In an embodiment, p and q is each 0, or p and q is each 1, and R a  and R b  are each a C 1-3  alkyl group, specifically methyl, disposed meta to the hydroxy group on each arylene group. X a  is a bridging group connecting the two hydroxy-substituted aromatic groups, where the bridging group and the hydroxy substituent of each C 6  arylene group are disposed ortho, meta, or para (specifically para) to each other on the C 6  arylene group, for example, a single bond, —O—, —S—, —S(O)—, —S(O) 2 —, —C(O)—, or a C 1-18  organic group, which can be cyclic or acyclic, aromatic or non-aromatic, and can further include heteroatoms such as halogens, oxygen, nitrogen, sulfur, silicon, or phosphorous. For example, X a  can be a substituted or unsubstituted C 3-18  cycloalkylidene; a C 1-25  alkylidene of the formula —C(R c )(R d )— wherein R c  and R d  are each independently hydrogen, C 1-12  alkyl, C 1-12  cycloalkyl, C 7-12  arylalkyl, C 1-12  heteroalkyl, or cyclic C 7-12  heteroarylalkyl; or a group of the formula —C(═R e )— wherein R e  is a divalent C 1-12  hydrocarbon group. 
     Some illustrative examples of specific dihydroxy compounds include the following: bisphenol compounds such as 4,4′-dihydroxybiphenyl, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, bis(4-hydroxyphenyl)methane, bis(4-hydroxyphenyl)diphenylmethane, bis(4-hydroxyphenyl)-1-naphthylmethane, 1,2-bis(4-hydroxyphenyl)ethane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 2-(4-hydroxyphenyl)-2-(3-hydroxyphenyl)propane, bis(4-hydroxyphenyl)phenylmethane, 2,2-bis(4-hydroxy-3-bromophenyl)propane, 1,1-bis (hydroxyphenyl)cyclopentane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)isobutene, 1,1-bis(4-hydroxyphenyl)cyclododecane, trans-2,3-bis(4-hydroxyphenyl)-2-butene, 2,2-bis(4-hydroxyphenyl)adamantane, alpha, alpha′-bis(4-hydroxyphenyl)toluene, bis(4-hydroxyphenyl)acetonitrile, 2,2-bis(3-methyl-4-hydroxyphenyl)propane, 2,2-bis(3-ethyl-4-hydroxyphenyl)propane, 2,2-bis(3-n-propyl-4-hydroxyphenyl)propane, 2,2-bis(3-isopropyl-4-hydroxyphenyl)propane, 2,2-bis(3-sec-butyl-4-hydroxyphenyl)propane, 2,2-bis(3-t-butyl-4-hydroxyphenyl)propane, 2,2-bis(3-cyclohexyl-4-hydroxyphenyl)propane, 2,2-bis(3-allyl-4-hydroxyphenyl)propane, 2,2-bis(3-methoxy-4-hydroxyphenyl)propane, 2,2-bis(4-hydroxyphenyl)hexafluoropropane, 1,1-dichloro-2,2-bis(4-hydroxyphenyl)ethylene, 1,1-dibromo-2,2-bis(4-hydroxyphenyl)ethylene, 1,1-dichloro-2,2-bis(5-phenoxy-4-hydroxyphenyl)ethylene, 4,4′-dihydroxybenzophenone, 3,3-bis(4-hydroxyphenyl)-2-butanone, 1,6-bis(4-hydroxyphenyl)-1,6-hexanedione, ethylene glycol bis(4-hydroxyphenyl)ether, bis(4-hydroxyphenyl)ether, bis(4-hydroxyphenyl)sulfide, bis(4-hydroxyphenyl)sulfoxide, bis(4-hydroxyphenyl)sulfone, 9,9-bis(4-hydroxyphenyl)fluorine, 2,7-dihydroxypyrene, 6,6′-dihydroxy-3,3,3′,3′-tetramethylspiro(bis)indane (“spirobiindane bisphenol”), 3,3-bis(4-hydroxyphenyl)phthalimide, 2,6-dihydroxydibenzo-p-dioxin, 2,6-dihydroxythianthrene, 2,7-dihydroxyphenoxathin, 2,7-dihydroxy-9,10-dimethylphenazine, 3,6-dihydroxydibenzofuran, 3,6-dihydroxydibenzothiophene, and 2,7-dihydroxycarbazole; resorcinol, substituted resorcinol compounds such as 5-methyl resorcinol, 5-ethyl resorcinol, 5-propyl resorcinol, 5-butyl resorcinol, 5-t-butyl resorcinol, 5-phenyl resorcinol, 5-cumyl resorcinol, 2,4,5,6-tetrafluoro resorcinol, 2,4,5,6-tetrabromo resorcinol, or the like; catechol; hydroquinone; substituted hydroquinones such as 2-methyl hydroquinone, 2-ethyl hydroquinone, 2-propyl hydroquinone, 2-butyl hydroquinone, 2-t-butyl hydroquinone, 2-phenyl hydroquinone, 2-cumyl hydroquinone, 2,3,5,6-tetramethyl hydroquinone, 2,3,5,6-tetra-t-butyl hydroquinone, 2,3,5,6-tetrafluoro hydroquinone, 2,3,5,6-tetrabromo hydroquinone, or the like. 
     Specific dihydroxy compounds include resorcinol, 2,2-bis(4-hydroxyphenyl) propane (“bisphenol A” or “BPA”, in which each of A 1  and A 2  is p-phenylene and X a  is isopropylidene in formula (3)), 3,3-bis(4-hydroxyphenyl) phthalimidine, 2-phenyl-3,3-bis(4-hydroxyphenyl) phthalimidine (also known as N-phenyl phenolphthalein bisphenol, “PPPBP”, or 3,3-bis(4-hydroxyphenyl)-2-phenylisoindolin-1-one), 1,1-bis(4-hydroxy-3-methylphenyl)cyclohexane (DMBPC), and 1,1-bis(4-hydroxy-3-methylphenyl)-3,3,5-trimethylcyclohexane (isophorone bisphenol). 
     These aromatic polycarbonates can be manufactured by known processes, for example, by reacting a dihydric phenol with a carbonate precursor, such as phosgene, in accordance with methods set forth in the above-cited literature and in U.S. Pat. No. 4,123,436, or by transesterification processes such as are disclosed in U.S. Pat. No. 3,153,008, as well as other processes known to those skilled in the art. 
     It is also possible to employ two or more different dihydric phenols in the event a polycarbonate copolymer or interpolymer rather than a homopolymer is desired. Polycarbonate copolymers can include two or more different types of carbonate units, for example units derived from BPA and PPPBP (commercially available under the trade designation XHT from the Innovative Plastics division of SABIC); BPA and DMBPC (commercially available under the trade designation DMX from the Innovative Plastics division of SABIC); or BPA and isophorone bisphenol (commercially available under the trade name APEC from Bayer). The polycarbonate copolymers can further comprise non-carbonate repeating units, for example repeating ester units (polyester-carbonates), such as those comprising bisphenol A carbonate units and isophthalate-terephthalate-bisphenol A ester units, also commonly referred to as poly(carbonate-ester)s (PCE) or poly(phthalate-carbonate)s (PPC), depending on the relative ratio of carbonate units and ester units, also commonly referred to as poly(carbonate-ester)s (PCE) or poly(phthalate-carbonate)s (PPC), depending on the relative ratio of carbonate units and ester units, or those comprising bisphenol A carbonate units and C 6-12  dicarboxy ester units (commercially available under the trade designation HFD from the Innovative Plastics division of SABIC); repeating siloxane units (polycarbonate-siloxanes), for example those comprising bisphenol A carbonate units, isophthalate-terephthalate-bisphenol A ester units, and siloxane units (e.g., blocks containing 5 to 200 dimethylsiloxane units), such as those commercially available under the trade name FST from the Innovative Plastics division of SABIC; or both ester units and siloxane units (polycarbonate-ester-siloxanes), for example those comprising bisphenol A carbonate units, isophthalate-terephthalate-bisphenol A ester units, and siloxane units (e.g., blocks containing 5 to 200 dimethylsiloxane units), such as those commercially available under the trade name FST from the Innovative Plastics division of SABIC. Branched polycarbonates are also useful, such as are described in U.S. Pat. No. 4,001,184, or highly-branched polycarbonate homopolymers containing cyanophenol endcaps, such as those commercially available under the trade designation CFR from the Innovative Plastics division of SABIC. Also, there can be utilized combinations of linear polycarbonate and a branched polycarbonate. Moreover, combinations of any of the above materials may be used. 
     In any event, the preferred aromatic polycarbonate is a homopolymer, e.g., a homopolymer derived from 2, 2-bis(4-hydroxyphenyl)propane (bisphenol-A) and a carbonate or carbonate precursor, commercially available under the trade designation LEXAN from SABIC. 
     The thermoplastic polycarbonates used herein possess a certain combination of chemical and physical properties. They are made from at least 50 mole % bisphenol A, and have a weight-average molecular weight (Mw) of 10,000 to 50,000 grams per mole (g/mol) measured by gel permeation chromatography (GPC) calibrated on polycarbonate standards, and have a glass transition temperature (Tg) from 130 to 180 degrees Centigrade (° C.). 
     Besides this combination of physical properties, these thermoplastic polycarbonate compositions may also possess certain optional physical properties. These other physical properties include having a tensile strength at yield of greater than 5,000 pounds per square inch (psi), and a flex modulus at 100° C. greater than 1,000 psi (as measured on 3.2 mm bars by dynamic mechanical analysis (DMA) as per ASTM D4065-01). 
     Other ingredients can also be added to the monofilaments. These include colorants such as solvent violet 36, pigment blue 60, pigment blue 15:1, pigment blue 15.4, carbon black, titanium dioxide or any combination comprising at least one of the foregoing. 
     A more complete understanding of the components, processes, and apparatuses disclosed herein can be obtained by reference to the accompanying drawings. These figures (also referred to herein as “FIG.”) are merely schematic representations based on convenience and the ease of demonstrating the present disclosure, and are, therefore, not intended to indicate relative size and dimensions of the devices or components thereof and/or to define or limit the scope of the exemplary embodiments. Although specific terms are used in the following description for the sake of clarity, these terms are intended to refer only to the particular structure of the embodiments selected for illustration in the drawings, and are not intended to define or limit the scope of the disclosure. In the drawings and the following description below, it is to be understood that like numeric designations refer to components of like function. 
       FIG. 1  illustrates an extrusion die  10  which can be used in an additive manufacturing device (e.g., a fused deposition modeling device) to deposit a layer of the multilayered extrudate  20  in a pattern  100  on a platform  2  (see  FIG. 4 ). The extrusion die  10  can have an opening  36  extending through the extrusion die  10 . Within the extrusion die  10  the opening  36  can form a feed channel  38  which can correspond to extrudate flow area  37  at an exit  12  of the extrusion die  10 . The extrusion die  10  can include two or more feed channels  38  corresponding to two or more extrudate flow areas  37 . 
     The extrusion die  10  can be used to form a multilayered extrudate  20  from a first polymer material  30  and a second material  40 . The first polymer material  30  can be in the form of a first filament  32 . The first polymer material  30  can be a pellet or a powder and can be introduced to the extrusion die in a flowable form, such as after progressing through a heating section (e.g., screw apparatus as used in an injection molding process). The first polymer material  30  can be heated within the extrusion die  10 . Heating within the extrusion die  10  can maintain the first polymer material  30  in a flowable form, can change the phase of the first polymer material  30  from a non-flowable form to a flowable form, such as in the case of a filament  32 , or can perform both functions. The first polymer material  30  can be positioned to form a core layer  23  of the multilayered extrudate  20  as it moves through the extrusion die  10 . The core layer  23  of first polymer material  30  can be fully or partially surrounded by the second material  40  along at least a portion of an extrusion axis  14  which can be an axis parallel to a movement direction  4  of the multilayered extrudate  20  (e.g., the z-axis in  FIGS. 1-3 ). 
     The cross-sectional shape of the multilayered extrudate  20  can include any shape, not limited to, but including circular, elliptical, and polygonal (e.g., having straight or curved edges). The cross-sectional shape of the multilayered extrudate  20  can by asymmetric about the extrusion axis  14 . The cross-sectional area (e.g., in the x-y plane in  FIGS. 1-3 ) of the first polymer material  30  can be 0.08 millimeter (mm) to 1 mm, for example, 0.1 mm to 0.5 mm, or, 0.02 mm to 0.03 mm, or, 0.25 mm. 
     The second material  40  can include a solvent, a release agent, a second polymer material  80  (a material extrusion material as described above) (e.g., see  FIG. 2 ), a functional coating material (e.g., abrasion resistance coating, ultraviolet light protective coating, or the like), or a combination comprising at least one of the foregoing. The second material  40  can be stored in a reservoir  42  of any size (e.g., volume, shape). The second material  40  can be fed through a feed channel  38  (e.g., a second feed channel). 
     A release agent can be any material that does not stick to the build material and/or prevent the build material from sticking to the support material. Release agents can include a carboxylic acid ester, an ester of a saturated aliphatic long chain monocarboxylic acid (e.g., a ester of C 12-30  aliphatic monocarboxylic acid), a saturated aliphatic carboxylic acid with 10 to 20 carbon atoms per molecule, a univalent aliphatic long chain alcohol, a paraffin wax, an ester wax of montanic acid (e.g., stearyl ester of behenic acid), mono or polyhydroxy aliphatic saturated alcohol (e.g., butyl stearate or stearic acid), an aromatic hydroxy compound with from 1 to 6 hydroxyl groups, a 4-hydric to 6-hydric alcohol, or a combination comprising at least one of the foregoing. It has been found that the addition of saturated and unsaturated normal fatty acids having from fourteen (14) to thirty-six (36) carbon atoms, inclusive, enhance the mold release capability of the other agents. Examples of the saturated acids include myristic, palmitic, stearic, arachidic, behenic and hexatrieisocontanoic (C36) acids. Examples of unsaturated acids include palmitoleic, oleic, linolenic and cetoleic. 
     The desired solvent will specific to the particular material that is employed. It can include water (e.g., steam), an acetate (e.g., ethyl acetate, ethoxyethyl acetate, methoxyethyl acetate), a ketone (e.g., acetone, methyl ethyl ketone, methyl isobutyl ketone, or aliphatic ketones (e.g., cyclic ketones, such as cyclohexanone)), xylene, white spirit, heavy coal-tar naphtha, kerosene, pinene and turpentine, toluene, or a combination of at least one of the foregoing. 
     In some embodiments, it may be desirable to additional include coatings to the encompass either the build material or the support material or both. These coatings can include UV- and thermally-cured coatings such as UV- and thermally-cured acrylic and epoxy polymers. In some embodiments, it may be desirable to employ a heated build chamber. 
     The second material  40  can move through the extrusion die  10  and can form a layer  24  of the multilayered extrudate. The layer  24  can partially or fully surround the core layer  23  (e.g., can form a perimeter layer around the core in a cross section of the multilayered extrudate  20  taken in the x-y plane of  FIGS. 1-3 ). The layer  24  can partially or fully surround the core layer  23  along a portion of the multilayered extrusion  20  extending along the extrusion axis  14 . A surrounding layer (e.g. layer  24 ) can be adjacent to the core layer  23  or can abut the core layer  23 . 
     The cross-sectional shape of the layer  24  can include any shape. The cross-sectional shape of the layer  24  can be the same shape as the core layer  23 . The cross-sectional area (e.g., in the x-y plane in  FIGS. 1-3 ) of the layer  24  of the second material can be 0.08 millimeter (mm) to 1 mm, for example, 0.1 mm to 0.5 mm, or, 0.2 mm to 0.3 mm, or, 0.25 mm. 
     The second material  40  can include a second polymer material  80  in the form of a second filament  44  of (e.g.  FIGS. 2-3 ). The second polymer material  80  can be a pellet or a powder and can be introduced to the extrusion die in a flowable form, such as after progressing through a heating section (e.g., screw apparatus as used in an injection molding process). The second polymer material  80  can be heated within the extrusion die  10 . Heating within the extrusion die  10  can maintain the second polymer material  30  in a flowable form, can change the phase of the second polymer material  80  from a non-flowable form to a flowable form, such as in the case of a second filament  44 , or can perform both functions. The second polymer material  80  can be a different type of polymer than the first polymer material  30 . For example, the second polymer material  80  can be of a different chemical composition, can have different physical properties (e.g., impact strength, glass transition temperature, hardness, flexural modulus, tensile strength, and the like), can have different additives, can have a different color, such as including a different colorants, and the like, in comparison to the first polymer material  30 . In an embodiment, the second polymer material  80  can have a higher impact strength than the first polymer material  30  as determined by ASTM D256. 
       FIG. 3  is an illustration of an extrusion die  11  including a heating device  17  disposed adjacent to a wall  16  of a feed channel  38 . The extrusion die  11  can include a cooling device  18  which can be disposed adjacent to a wall  16  of the feed channel  38  through which the extruding material moves. A cooling device  18  (e.g., a coolant channel, thermoelectric device (e.g., a device that demonstrates the Peltier effect), heat pipe, and the like) can be located such that the second material  40  is kept below its vaporization temperature as it passes through the extrusion die  11 . The extrusion die  11  can include an insulative portion  19  to reduce heat transfer between the materials that pass through the extrusion die  11 . 
     The second polymer material  80  can move through the extrusion die  11  to form a portion of the multilayered extrudate  20 . The second material  40  can move through the extrusion die  11  and can form a layer  26  of the multilayered extrudate  20 . The layer  26  can partially or fully surround the core layer  23  (e.g., can form a perimeter layer around the core in a cross section of the multilayered extrudate  20  taken in the x-y plane of  FIGS. 1-3 ). The layer  26  can partially or fully surround the core layer  23  along a portion of the multilayered extrudate  20  extending along the extrusion axis  14 . The second polymer material  80  can partially or fully surround the first polymer material  30 . The second material  40  can form an intermediate layer  26  between the first polymer material  30  and the second polymer material  80  of the multilayered extrudate  20 . A surrounding layer (e.g. layers  24  or  26 ) can be adjacent to an inner layer (e.g.,  23 ,  26 ) or can abut an inner layer (e.g.,  23 ,  26 ). In an embodiment, the second polymer material  80  can form an interlayer between the first polymer material  30  and the second material, such as a solvent, abutting both the first polymer material  30  and the second material  40 . In an embodiment, the first polymer material  30  can form a core layer surrounded by and abutting a first solvent, which in turn is surrounded by and abutting a second polymer material  80 , which in turn is surrounded by and abutting a second solvent. In an embodiment, the first polymer material  30  can form a core layer surrounded by and abutting a first solvent, which in turn is surrounded by and abutting a second polymer material  80 , which in turn is surrounded by and abutting a release agent. 
       FIG. 4  illustrates a cross section of a pattern  100  of multilayered extrudate  20  deposited on a plat form  2 . The movement of the second material  40  can be stopped while extrusion of the first polymer material  30  continues which can form paths  52  free of second material  40 . In this way, portions of the pattern  100  can be free of the second material  40 . The second material  40  can be extruded in preselected portions of the pattern  100 . In other words, the second material can be disposed in some areas of the pattern while other areas of the patter are free of the second material. The second material  40  can form a surface  54  (e.g. outer surface) of the model material  50  which can have a functional coating (e.g., abrasion resistant coating, ultraviolet protective coating, and the like). For example, the second material  40  can form an interface  60  between portions of model material  50  and portions of support material  70 . In an embodiment, the first polymer material  30  can be used as the support material  70  and as the model material  50  where the interface  60  between the model material  50  and the support material  70  can be formed by the second material  40 . 
     The cross-sectional area of the second material  40  in the multilayered extrudate  20  can be changed during the extrusion process to provide the desired amount of second material  40  as a function of the position within the three dimensional object. For example, a portion  28  of the multilayered extrudate  20  can have a larger cross-sectional area of the second material (e.g., release agent). A larger cross-sectional area can include a thicker portion or extending around more, surrounding more, of the first polymer material  30 . This portion  28  can be deposited in a layer  25  of the pattern  100  that can form an interface  60  between the model material  50  and the support material  70 . 
     Various strategies can be employed to adjust the cross-sectional area of the second material  40  that is extruded into the multilayered extrudate  20  in a path  29  and/or layer  25  of the pattern  100 . A strategy can include swapping the extrusion die ( 10 ,  11 ) during the manufacturing process (e.g., in an automated fashion) with another extrusion die ( 10 ,  11 ). A strategy can include changing the cross-sectional area of an opening  36  of the extrusion die ( 10 ,  11 ). Any suitable strategy can be used to extrude a different shape of the second material  40 , a different cross-sectional area of the second material  40 , a different volumetric flow rate of the second material  40 , or a combination comprising at least one of the foregoing, including adjusting the cross-sectional shape of the layer  24  of the second material  40  (e.g., blocking portions of the second material  40  extrudate flow area  37  within the extrusion die ( 10 ,  11 )). 
       FIG. 5  is an illustration of a pattern  102  including a multilayered extrudate  20  deposited in layers  25 . The multilayer extrudate  20  can have a core layer  23  of a first polymer material  30  throughout the pattern  102 . The second material  40  of the multilayered extrudate  20  can be changed from a solvent  46  to a release agent  48  in portions of the pattern  102 . In this way the adhesion between layers of the model material  50  can be improved by the solvent  46  relative to model material without a solvent layer and the support material  70  can be more easily separated from the model material  50  due to the interface  60  formed by the release agent  48  once the pattern  102  is formed. 
       FIG. 6  is an illustration of a pattern  104  including multilayered extrudate  20  deposited in layers  25 . The multilayered extrudate  20  can have a core layer  23  of a first polymer material  30  throughout the pattern  102 . The multilayered extrudate  20  can have a first interlayer  64  of a first solvent  65  throughout the pattern  102 . The multilayered extrudate  20  can have a second interlayer  66  of a second polymer material  80  throughout the pattern  102 . The multilayered extrudate  20  can have an outer layer  68  of a second material  40  throughout the pattern  102 . The second material  40  can include a release agent  48 , a second solvent  72 , a function coating, or a combination of at least one of the foregoing. The outer layer  68  of the multilayered extrudate  20  can be changed from a second solvent  72  to a release agent  48  in portions of the pattern  102 . In this way the adhesion between layers ( 25 ,  64 ,  66 ,  68 ) of the model material  50  can be improved by the solvents ( 65 ,  72 ) relative to other methods of manufacturing including model material  50  without solvents ( 65 ,  72 ). The support material  70  can be more easily separated from the model material  50  due to the interfaces  60  formed by the release agent  48  once the pattern  102  is formed. 
     Once formed the support material  70  can be separated from the model material  50  of the pattern ( 100 ,  102 ,  104 ). The use of a release agent along model/support interfaces can allow for easier removal of the support in comparison to other additive manufacturing methods. Additional post process steps such as sanding, curing, and/or additional finishing can be performed on the part. In an embodiment, utilizing a release agent along boundary surfaces within the article can reduce the need for post process steps since the model can be more separated from the support material more easily. Accordingly, an increase in production rate and product quality can be attained in using the system and methods described herein. 
     The following embodiments illustrate the present invention: 
     Embodiment 1 
     A method of forming a three dimensional object comprising: moving a first polymer material through a first feed channel of an extrusion die having multiple feed channels; moving a second material through a second feed channel of the extrusion die, wherein the second material comprises at least one of a solvent, a release agent, a coating, and a second polymer material; forming a multilayered extrudate along an extrusion axis, wherein the multilayered extrudate comprises the first polymer material and the second material, and wherein the extrusion axis is parallel to the movement of the multilayered extrudate; depositing a multitude of layers of the multilayered extrudate in a preset pattern on a platform; and fusing the multitude of layers to form the three dimensional object. 
     Embodiment 2 
     The method of Embodiment 1, wherein the second material comprises only one of the solvent, the release agent, the coating, and the second polymer material 
     Embodiment 3 
     The method of any of Embodiments 1-2, further comprising surrounding the first polymer material with the second material along a portion of the extrusion axis. 
     Embodiment 4 
     The method of any of Embodiments 1-3, further comprising stopping movement of the second material at a predetermined position of the pattern. 
     Embodiment 5 
     The method of any of Embodiments 1-4, further comprising heating the first polymer material to a temperature greater than or equal to the glass transition temperature or the melting point temperature of the first polymer material as it passes through the extrusion die. 
     Embodiment 6 
     The method of any of Embodiments 1-5, wherein the second material comprises the solvent; and further comprising moving a second polymer material through a third feed channel of the extrusion die; wherein the multilayered extrudate further comprises the second polymer material and the solvent surrounds the first polymer material and is disposed as an intermediate layer between the first polymer material and the second polymer material. 
     Embodiment 7 
     The method of Embodiments 6, further comprising heating the second polymer material to a temperature greater than or equal to the glass transition temperature or the melting point temperature of the second polymer material as it passes through the extrusion die. 
     Embodiment 8 
     The method of any of Embodiments 1-5, wherein the second material comprises at least one of the solvent and the release agent (preferably wherein the second material comprises the solvent or the release agent); and further comprising cooling the second material to a temperature less than or equal to the vaporization temperature of the second material as it passes through the extrusion die. 
     Embodiment 9 
     The method of any of Embodiments 8, wherein the second material comprises the solvent or the release agent; and further comprising washing the solvent or the release agent from the three dimensional object. 
     Embodiment 10 
     The method of any of Embodiments 1-9, wherein the first polymer material comprises a first filament, a first powder, a first pellet, or a combination of at least one of the foregoing. 
     Embodiment 11 
     The method of any of Embodiments 6-7, wherein the second material comprises the second polymer material and comprises a second filament, a second powder, a second pellet, or a combination of at least one of the foregoing. 
     Embodiment 12 
     The method of any of Embodiments 6-7 or 11, wherein the impact strength of the second polymer material is less than or equal to the impact strength of the first polymer material. 
     Embodiment 13 
     The method of any of Embodiments 1-12, further comprising adjusting a flow rate of the second material, a cross-sectional shape of the second material, a cross-sectional area of the second material, or a combination of at least one of the foregoing along a path of the pattern. 
     Embodiment 14 
     A method of forming a three dimensional object comprising: moving a first polymer material through a first feed channel of an extrusion die having multiple feed channels; moving a first solvent through a second feed channel of the extrusion die; forming a multilayered extrudate along an extrusion axis, wherein the multilayered extrudate comprises the first polymer material and the first solvent, and wherein the extrusion axis is parallel to the movement of the multilayered extrudate; depositing a multitude of layers of the multilayered extrudate in a preset pattern on a platform; and fusing the multitude of layers to form the three dimensional object. 
     Embodiment 15 
     The method of Embodiment 14, wherein the first solvent improves adhesion between the multitude of layers along all three dimensions of the three dimensional object. 
     Embodiment 16 
     The method of any of Embodiments 14-15, further comprising surrounding the first polymer material with the first solvent along a portion of the extrusion axis. 
     Embodiment 17 
     The method of any of Embodiments 14-16, further comprising moving a second polymer material through a third feed channel of the extrusion die; wherein the multilayered extrudate further comprises the second polymer material. 
     Embodiment 18 
     The method of Embodiment 17, further comprising surrounding the first polymer material with the second polymer material along a portion of the extrusion axis, and wherein the first solvent forms an intermediate layer between and abutting both the first polymer material and the second polymer material. 
     Embodiment 19 
     The method of any of Embodiments 17-18, further comprising moving a second solvent through a fourth feed channel of the extrusion die, and wherein the multilayered extrudate further comprises the second solvent. 
     Embodiment 20 
     The method of Embodiment 19, further comprising surrounding the second polymer material with the second solvent along a portion of the extrusion axis. 
     Embodiment 21 
     The method of Embodiment 17, further comprising surrounding the first polymer material with the second polymer material along a portion of the extrusion axis, wherein the first solvent surrounds both the first polymer material and the second polymer material and forms an outer layer abutting the second polymer material. 
     Embodiment 22 
     The method of any of Embodiments 19-20, wherein the second solvent improves adhesion between the layers along all three dimensions of the three dimensional object. 
     Embodiment 23 
     The method of any of Embodiments 17-22, wherein the impact strength of the second polymer material is less than or equal to the impact strength of the first polymer material. 
     Embodiment 24 
     The method of any of Embodiments 14-23, further comprising adjusting a flow rate of the first solvent, a cross-sectional shape of the first solvent, a cross-sectional area of the first solvent, or a combination of at least one of the foregoing along a path of the pattern. 
     Embodiment 25 
     The method of any of Embodiments 14-24, further comprising stopping the movement of the first solvent at a predetermined position of the pattern. 
     Embodiment 26 
     The method of Embodiment 25, further comprising moving a release agent through the second feed channel of the extrusion die, wherein the multilayered extrudate comprises the first polymer material and the release agent. 
     Embodiment 27 
     The method of any of Embodiments 1-26, further comprising forming a support of the three dimensional object from the multilayered extrudate. 
     Embodiment 28 
     A method of forming a three dimensional object comprising: moving a first polymer material through a first feed channel of an extrusion die having multiple feed channels; moving a release agent through a second feed channel of the extrusion die; forming a multilayered extrudate along an extrusion axis, wherein the multilayered extrudate comprises the first polymer material and the release agent, and wherein the extrusion axis is parallel to the movement of the multilayered extrudate; depositing a multitude of layers of the multilayered extrudate in a preset pattern on a platform; and fusing the multitude of layers to form the three dimensional object. 
     Embodiment 29 
     The method of Embodiment 28, further comprising adjusting a flow rate of the release agent, a cross-sectional shape of the release agent, a cross-sectional area of the release agent, or a combination of at least one of the foregoing along a path of the pattern. 
     Embodiment 30 
     The method of any of Embodiments 28-29, further comprising stopping movement of the release agent at a predetermined position of the pattern. 
     Embodiment 31 
     The method of any of Embodiments 28-30, further comprising moving a second polymer material through a third feed channel of the extrusion die, and wherein the multilayered extrudate further comprises the second polymer material. 
     Embodiment 32 
     The method of Embodiment 31, further comprising surrounding both the first polymer material and the second polymer material with the release agent along a portion of the extrusion axis, wherein the release agent forms an outer layer abutting the second polymer material 
     Embodiment 33 
     The method of any of Embodiments 28-32, further comprising forming a support of the three dimensional object from the multilayered extrudate. 
     Embodiment 34 
     The method of any of Embodiments 28-33, further comprising washing the release agent from the three dimensional object. 
     Embodiment 35 
     A method of forming a three dimensional object comprising: moving a first polymer material through a first feed channel of an extrusion die having multiple feed channels; moving a second material through a second feed channel of the extrusion die, wherein the second material comprises at least one of a first solvent, a release agent, and a coating, or a second polymer material; forming a multilayered extrudate along an extrusion axis, wherein the multilayered extrudate comprises the first polymer material and the second material, and wherein the extrusion axis is parallel to the movement of the multilayered extrudate; depositing a multitude of layers of the multilayered extrudate in a preset pattern on a platform; and fusing the multitude of layers to form the three dimensional object. 
     Embodiment 36 
     The method of Embodiment 35, further comprising surrounding the first polymer material with the second material along a portion of the extrusion axis. 
     Embodiment 37 
     The method of any of Embodiments 35-36, further comprising stopping movement of the second material at a predetermined position of the pattern. 
     Embodiment 38 
     The method of any of Embodiments 35-37, wherein the second material comprises at least one of the first solvent and the release agent; and further comprising cooling the second material to a temperature less than or equal to the vaporization temperature of the second material as it passes through the extrusion die. 
     Embodiment 39 
     The method of any of Embodiments 35-38, wherein the second material comprises the first solvent. 
     Embodiment 40 
     The method of any of Embodiments 35-39, further comprising moving a second polymer material through a third feed channel of the extrusion die, and wherein the multilayered extrudate further comprises the second polymer material. 
     Embodiment 41 
     The method of Embodiment 40, wherein the first solvent surrounds the first polymer material and is disposed as an intermediate layer between the first polymer material and the second polymer material. 
     Embodiment 42 
     The method of any of Embodiments 35-39, wherein the second material comprises the second polymer material. 
     Embodiment 43 
     The method of Embodiment 42, further comprising moving the second polymer material through a third feed channel of the extrusion die; wherein the multilayered extrudate further comprises the second polymer material; and surrounding the first polymer material with the second polymer material along a portion of the extrusion axis, and wherein the first solvent forms an intermediate layer between and abutting both the first polymer material and the second polymer material. 
     Embodiment 44 
     The method of any of Embodiments 35-43, wherein the second material comprises the second polymer material and comprises a second filament, a second powder, a second pellet, or a combination of at least one of the foregoing. 
     Embodiment 45 
     The method of any of Embodiments 35-44, wherein the impact strength of the second polymer material is less than or equal to the impact strength of the first polymer material. 
     Embodiment 46 
     The method of any of Embodiments 35-45, wherein the first solvent improves adhesion between the multitude of layers along all three dimensions of the three dimensional object. 
     Embodiment 47 
     The method of any of Embodiments 35-46, further comprising surrounding the first polymer material with the first solvent along a portion of the extrusion axis. 
     Embodiment 48 
     The method of any of Embodiments 35-47, wherein the impact strength of the second polymer material is less than or equal to the impact strength of the first polymer material. 
     Embodiment 49 
     The method of any of Embodiments 35-48, wherein the second material comprises the release agent. 
     Embodiment 50 
     The method of any of Embodiments 35-49, further comprising stopping the movement of the first solvent at a predetermined position of the pattern, moving the release agent through the second feed channel of the extrusion die, wherein the multilayered extrudate comprises the first polymer material and the release agent. 
     Embodiment 51 
     The method of any of Embodiments 35-50, further comprising adjusting a flow rate of the second material, a cross-sectional shape of the second material, a cross-sectional area of the second material, or a combination of at least one of the foregoing along a path of the pattern. 
     Embodiment 52 
     The method of any of Embodiments 35-51, further comprising surrounding both the first polymer material and the second polymer material with the release agent along a portion of the extrusion axis, wherein the release agent forms an outer layer abutting the second polymer material. 
     Embodiment 53 
     The method of any of Embodiments 35-52, further comprising forming a support of the three dimensional object from the multilayered extrudate. 
     Embodiment 54 
     An article of manufacture comprising the three dimensional object of any of Embodiments 35-53. 
     Embodiment 55 
     An article of manufacture comprising: a three dimensional object comprising a part made from a first polymer material and a support made from the first polymer material wherein the part and the support are separated by a release agent. 
     Embodiment 56 
     The article of manufacturing of Embodiment 55, wherein the part further comprises a second polymer material. 
     Embodiment 57 
     The article of manufacturing of any of Embodiments 35-56, wherein the impact strength of the second polymer material is less than or equal to the impact strength of the first polymer material. 
     Embodiment 58 
     The article of manufacturing of any of Embodiment 35-55, wherein the first polymer material further comprises a uniquely encoded chemical identifier, a uniquely encoded microscopic material, or both a uniquely encoded chemical identifier and a uniquely encoded microscopic material. 
     Embodiment 59 
     The article of manufacturing of any of Embodiments 35-58, wherein one of the first polymer material and the second polymer material further comprises a uniquely encoded chemical identifier, a uniquely encoded microscopic material, or both a uniquely encoded chemical identifier and a uniquely encoded microscopic material. 
     Embodiment 60 
     The article of manufacturing of any of Embodiments 35-59, wherein one of the first polymer material and the second polymer material comprises polycarbonate, acrylonitrile butadiene styrene, acrylic rubber, liquid crystal polymer, methacrylate styrene butadiene, polyacrylates (acrylic), polyacrylonitrile, polyamide, polyamide-imide, polyaryletherketone, polybutadiene, polybutylene, polybutylene terephthalate, polycaprolactone, polyethylene terephthalate, polycyclohexylene dimethylene terephthalate, polyhydroxyalkanoates, polyketone, polyesters, polyester carbonates, polyethylene, polyetheretherketone, polyetherketoneketone, polyetherimide, polyethersulfone, polysulfone, polyimide, polylactic acid, polymethylpentene, polyolefins, polyphenylene oxide, polyphenylene sulfide, polyphthalamide, polypropylene, polystyrene, polysulfone, polyphenylsulfone, polytrimethylene terephthalate, polyurethane, styrene-acrylonitrile, polycarbonate copolymers, silicone polycarbonate copolymers, or a combination comprising at least one of the foregoing. 
     Embodiment 61 
     The article of manufacturing of any of Embodiments 35-60, wherein the release agent comprises a carboxylic acid ester, an ester of a saturated aliphatic long chain monocarboxylic acid, a saturated aliphatic carboxylic acid with 10 to 20 carbon atoms per molecule, a univalent aliphatic long chain alcohol, a paraffin wax, an ester wax of montanic acid, mono or polyhydroxy aliphatic saturated alcohol, an aromatic hydroxy compound with from 1 to 6 hydroxyl groups, a 4-hydric to 6-hydric alcohol, or a combination comprising at least one of the foregoing. 
     Embodiment 62 
     The article of manufacturing of any of Embodiments 35-61, wherein the solvent comprises water, an acetate, a ketone, xylene, white spirit, heavy coal-tar naphtha, kerosene, pinene and turpentine, toluene, or a combination of at least one of the foregoing. 
     Embodiment 63 
     The article of manufacturing of any of Embodiments 35-62, wherein the article comprises areas free of the second material. 
     Embodiment 64 
     The article of manufacturing of any of Embodiments 35-63, wherein the second material forms a pattern in the article. 
     Embodiment 65 
     The article of manufacturing of any of Embodiments 35-64, wherein the second material is not located randomly in the article. 
     In general, the invention may alternately comprise, consist of, or consist essentially of, any appropriate components herein disclosed. The invention may additionally, or alternatively, be formulated so as to be devoid, or substantially free, of any components, materials, ingredients, adjuvants or species used in the prior art compositions or that are otherwise not necessary to the achievement of the function and/or objectives of the present invention. 
     All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other (e.g., ranges of “up to 25 wt. %, or more specifically, 5 wt. % to 20 wt. %”, is inclusive of the endpoints and all intermediate values of the ranges of “5 wt. % to 25 wt. %” etc.). “Combination” is inclusive of blends, mixtures, alloys, reaction products, and the like. Furthermore, the terms “first,” “second,” and the like, herein do not denote any order, quantity, or importance, but rather are used to denote one element from another. The terms “a” and “an” and “the” herein do not denote a limitation of quantity, and are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The suffix “(s)” as used herein is intended to include both the singular and the plural of the term that it modifies, thereby including one or more of that term (e.g., the film(s) includes one or more films). Reference throughout the specification to “one embodiment”, “another embodiment”, “an embodiment”, and so forth, means that a particular element (e.g., feature, structure, and/or characteristic) described in connection with the embodiment is included in at least one embodiment described herein, and may or may not be present in other embodiments. In addition, it is to be understood that the described elements may be combined in any suitable manner in the various embodiments. 
     While particular embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are or may be presently unforeseen may arise to applicants or others skilled in the art. Accordingly, the appended claims as filed and as they may be amended are intended to embrace all such alternatives, modifications variations, improvements, and substantial equivalents.