Multi-material polymer filament for three-dimensional printing
A thermoplastic filament comprising multiple polymers of differing flow temperatures in a geometric arrangement is described. A method for producing such a filament is also described. Because of the difference in flow temperatures, there exists a temperature range at which one polymer is mechanically stable while the other is flowable. This property is extremely useful for creating thermoplastic monofilament feedstock for three-dimensionally printed parts, wherein the mechanically stable polymer enables geometric stability while the flowable polymer can fill gaps and provide strong bonding and homogenization between deposited material lines and layers. These multimaterial filaments can be produced via thermal drawing from a thermoplastic preform, which itself can be three-dimensionally printed. Furthermore, the preform can be printed with precisely controlled and complex geometries, enabling the creation of a filament or fiber with a wide range of applications. A method is also described for including an interior thread that adds structural reinforcement or functional properties, such as electrical conductivity or optical waveguiding, to the filament.
1 . A filament or preform for use in 3D printing, the filament or preform comprising a first thermoplastic polymer and a second thermoplastic polymer, the filament or preform having an outer surface;
wherein the first thermoplastic polymer and the second thermoplastic polymer are physically associated in a geometric arrangement, in which a flow temperature of said first thermoplastic polymer is greater than 10 degrees Celsius higher than a flow temperature of said second thermoplastic polymer,
wherein the cross-sectional geometry of the first thermoplastic polymer comprises a central node with extending arms substantially surrounded by the second thermoplastic polymer in the geometric arrangement,
wherein at least 90% of the outer surface is comprised of the second thermoplastic polymer,
wherein the filament or preform has a diameter of at least 1 millimeter,
wherein the cross-sectional geometry of the second thermoplastic polymer consists of a second contiguous shape and the cross-sectional geometry of the first thermoplastic polymer consists of a first contiguous shape and considering an area defined by a circumscribed circle around the first contiguous shape, the area fraction of the first thermoplastic polymer within the circumscribed circle is less than 75%,
wherein the filament or preform is configured to be 3D printed as multiple layers of extrudate through a nozzle using a 3D printer which accepts continuous filaments with a diameter of at least 1 mm, and
further wherein the first and second thermoplastic polymers are selected so that the interlaminar strength between the multiple layers of extrudate, after annealing at a temperature above the flow temperature of the second thermoplastic polymer and below the flow temperature of the first thermoplastic polymer, is at least 10% of the molded strength of the second thermoplastic polymer.
2 . The filament or preform of claim 1 , where the second thermoplastic polymer comprises a volume of material that forms an outer band of the filament or preform, and where the band thickness is at least 10% of the diameter of the filament or preform.
3 . The filament or preform of claim 1 , wherein said regular geometric arrangement is an interlocking geometric arrangement.
4 . The filament or preform of claim 1 , wherein at least 95 percent of the outer surface by area is comprised of the second thermoplastic polymer.
5 . The filament or preform of claim 1 , where there are at least 3 extending arms.
6 . The filament or preform of claim 1 , where each arm is either a rectangle, triangle, ellipse, or trapezoid.
7 . The filament or preform of claim 1 , where the first thermoplastic polymer or the second thermoplastic polymer are amorphous polymers.
8 . The filament or preform of claim 1 , where the first thermoplastic polymer or the second thermoplastic polymer are semi-crystalline polymers.
9 . The filament or preform of claim 1 , where said first thermoplastic polymer, said second thermoplastic polymer, or both comprise one or more of a thermoplastic material selected from the group consisting of: acrylonitrilebutadienestyrene (ABS); high density polyethylene (HDPE); low density polyethylene (LDPE); polyamide (PA); polyamide imide (PAI); polyarylate (PAR); polyaryletherketone (PAEK); polybutylene terephthalate (PBT); polycarbonate (PC); polyester; polyether sulfone (PES); polyetherketoneketone (PEKK); polyetheretherketone (PEEK); polyetherimide (PEI); polyetherketone (PEK); polyetherketonetherketoneketone (PEKEKK); polyethlyene (PE); polyethylene terephthalate (PET); polyimide (PI); polylactic acid (PLA); polymethyl methacrylate (PMMA); polyoxymethylene (POM); polyphenylene oxide (PPO); polyphenylene sulfide (PPS); polyphenylsulfone (PPSU); polyphthalamide (PPA); polyphthalate carbonate (PPC); polyproplyene (PP); polystyrene (PS); polysulfone (PSF); polyurethane (PU); polyvinyl chloride (PVC); polyvinylidene fluoride (PVDF); styrene acrylonitrile (SAN); styrene maleic anhydride (SMA); ultrahigh molecular weight polyethylene (UHMWPE); high impact polystyrene (HIPS); polyvinyl alcohol (PVA); glycol-modified polyethylene terephthalate (PETG); polytetrafluoroethylene (PTFE); polyhydroxyalkanoate, polybutylene succinate (PBS), polycaprolactone (PCL), polyanhydride and thermotropic liquid crystalline polymers.
10 . The filament or preform of claim 1 further comprising at least one additional thermoplastic polymer, physically associated in a regular geometric arrangement, in which a flow temperature of one of the thermoplastic polymers is greater than 10 degrees Celsius higher than a flow temperature of at least one of the other thermoplastic polymers, and wherein at least 90% of the outer surface is comprised of one of the thermoplastic polymers that does not have the highest flow temperature.
11 . The filament or preform of claim 1 , wherein the filament or preform has a diameter of 1-3 millimeters.
12 . The filament or preform of claim 1 , wherein the flow temperature of said first thermoplastic polymer is greater than 20 degrees Celsius higher than a flow temperature of said second thermoplastic polymer.
13 . The filament or preform of claim 1 , where the second thermoplastic polymer comprises a volume of material that forms an outer band of the filament or preform, and where the band thickness is at least 15% of the diameter of the filament or preform.
14 . The filament or preform of claim 1 , where said first thermoplastic polymer, said second thermoplastic polymer, or both comprise one or more thermotropic liquid crystalline polymers.
15 . The filament or preform of claim 14 , wherein the one or more thermotropic liquid crystalline polymers comprise copolymers of 4-hydroxybenzoic acid (HBA) and 6-hydroxy-2-naphthoic acid (HNA).
16 . The filament or preform of claim 1 , wherein the geometric arrangement is selected from the group consisting of: (i) a cross-sectional geometry of the first thermoplastic polymer comprising a central node with three extending arms with triangularly-shaped end points surrounded by the second thermoplastic, and (ii) a cross-sectional geometry of the first thermoplastic polymer comprising a central node with five extending arms surrounded by the second thermoplastic and the arms do not extend to the edge of the filament or preform.
17 . The filament or preform of claim 1 , wherein the first and second thermoplastic polymers are selected so that multiple layers of extrudate, after annealing at a temperature above the flow temperature of the second thermoplastic polymer and below the flow temperature of the first thermoplastic polymer, exhibit ductile failure.
18 . The filament or preform of claim 1 , wherein the first and second thermoplastic polymers are selected so that the interlaminar strength between the multiple layers of extrudate, after annealing at a temperature above the flow temperature of the second thermoplastic polymer and below the flow temperature of the first thermoplastic polymer, is at least 25% of the molded strength of the second thermoplastic polymer.
19 . The filament or preform of claim 1 , wherein the first thermoplastic polymer is selected based on its suitability for resisting thermal deflection during annealing.
20 . A three dimensional object resulting from the deposition of multiple layers of extrudate through a nozzle using a 3D printer which accepts a heated filament or preform of claim 1 , and optionally annealed at a temperature above the flow temperature of the second thermoplastic polymer and below the flow temperature of the first thermoplastic polymer.
21 . The three dimensional object of claim 20 , wherein said first thermoplastic polymer, said second thermoplastic polymer, or both comprise one or more thermotropic liquid crystalline polymers.
22 . The three dimensional object of claim 20 , wherein the cross-sectional geometry of the extrudate of the filament or preform is preserved in the object after 3D printing and/or the optional annealing.
23 . The three dimensional object of claim 20 , wherein having been 3D printed into an object, that the multiple layers of extrudate have an interlaminar fracture toughness greater of at least 500 J/m 2 .
24 . The three dimensional object of claim 23 , wherein, if subsequently annealed, the multiple layers of annealed extrudate have an interlaminar fracture toughness of at least 3000 J/m 2 .
25 . The three dimensional object of claim 20 , wherein the layers of extrudate when 3D printed have a diameter less than 1 mm.
26 . A filament or preform for use in 3D printing, the filament or preform comprising a first thermoplastic polymer and a second thermoplastic polymer, the filament or preform having an outer surface;
wherein the first thermoplastic polymer and the second thermoplastic polymer are physically associated in a geometric arrangement, in which a flow temperature of said first thermoplastic polymer is greater than 10 degrees Celsius higher than a flow temperature of said second thermoplastic polymer,
wherein the filament or preform has a diameter of at least 1 millimeter,
wherein the first thermoplastic polymer comprises a central node with extending arms substantially surrounded by the second thermoplastic,
wherein said regular arrangement is an interlocking arrangement of the first and second thermoplastic polymers,
wherein the filament or preform is configured to be 3D printed as multiple layers of extrudate through a nozzle using a 3D printer which accepts continuous filaments with a diameter of at least 1 mm, and
further wherein the first and second thermoplastic polymers are selected so that the change in overall dimensions of the multiple layers of extrudate, after printing and subsequent annealing at a temperature above the flow temperature of the second thermoplastic polymer and below the flow temperature of the first thermoplastic polymer, is less than 10%.
27 . The filament or preform of claim 26 , wherein the extending arms do not reach the outer surface.
28 . The filament or preform of claim 26 , wherein the filament or preform has a diameter of 1-3 millimeters.
29 . The filament or preform of claim 26 , wherein the flow temperature of said first thermoplastic polymer is greater than 20 degrees Celsius higher than a flow temperature of said second thermoplastic polymer.
30 . The filament or preform of claim 26 , wherein the interlocking geometric arrangement is selected from the group consisting of: (i) a cross-sectional geometry of the first thermoplastic polymer comprising a central node and five spokes extending to the edge of the filament or preform having a flange at their ends surrounded by the second thermoplastic, (ii) a cross-sectional geometry of the first thermoplastic polymer comprising a central node and three spokes extending to the edge of the filament or preform having a flange at their ends surrounded by the second thermoplastic, (iii) a cross-sectional geometry of the first thermoplastic polymer comprising a central node with three extending arms with triangularly-shaped end points surrounded by the second thermoplastic, and (iv) a cross-sectional geometry of the first thermoplastic polymer comprising a central node with five extending arms surrounded by the second thermoplastic and the arms do not extend to the edge of the filament or preform.
31 . A three dimensional object formed of multiple layers of extrudate of the filament or preform of claim 26 passed through a nozzle using a 3D printer, and optionally annealed at a temperature above the flow temperature of the second thermoplastic polymer and below the flow temperature of the first thermoplastic polymer.
32 . The three dimensional object of claim 31 , wherein the cross-sectional geometry of the extrudate of the filament or preform is preserved in the object after 3D printing and/or the optional annealing.
33 . A filament or preform for use in 3D printing, the filament or preform comprising a first thermoplastic polymer and a second thermoplastic polymer, the filament or preform having an outer surface;
wherein the first thermoplastic polymer and the second thermoplastic polymer are physically associated in a geometric arrangement, in which a flow temperature of said first thermoplastic polymer is greater than 10 degrees Celsius higher than a flow temperature of said second thermoplastic polymer,
wherein the cross-sectional geometry of the first thermoplastic polymer comprises a central node with at least three extending arms, where each arm has the same length and uniform thickness along its length, surrounded by the second thermoplastic polymer,
wherein at least 50% of the outer surface is comprised of the second thermoplastic polymer,
wherein the filament or preform has a diameter of at least 1 millimeter, and
further wherein the filament or preform is configured to be 3D printed as multiple layers of extrudate through a nozzle using a 3D printer which accepts continuous filaments with a diameter of at least 1 mm, and the multiple layers of extrudate can be subsequently annealed above the flow temperature of the second polymer and below the flow temperature of the first thermoplastic polymer to provide an increase in the interlaminar strength between the printed multiple layers of extrudate of at least 100% after annealing.
34 . The filament or preform of claim 33 , wherein one of the polymers is a propellant or explosive.
35 . The filament or preform of claim 33 , wherein the geometric arrangement is a cross-sectional geometry of the first thermoplastic polymer comprising a central node with five extending arms surrounded by the second thermoplastic and the arms do not extend to the edge of the filament or preform.
36 . The filament or preform of claim 33 , wherein the first polymer comprises polycarbonate (PC) and the second polymer comprises acrylonitrile butadienestyrene (ABS).
37 . A three dimensional object formed of multiple layers of extrudate of the filament or preform of claim 33 passed through a nozzle using a 3D printer, and optionally annealed at a temperature above the flow temperature of the second thermoplastic polymer and below the flow temperature of the first thermoplastic polymer.
38 . The three dimensional object of claim 37 , wherein the cross-sectional geometry of the extrudate of the filament or preform is preserved in the object after 3D printing and/or the optional annealing.
39 . The filament or preform of claim 37 , wherein having been 3D printed into an object, the multiple layers of extrudate have an interlaminar fracture toughness of 282-566 J/m 2 , and if subsequently annealed, the multiple layers of annealed extrudate have an interlaminar fracture toughness of 730-3970 J/m 2 .
40 . A filament or preform, the filament or preform comprising a first thermoplastic polymer and a second thermoplastic polymer, the filament or preform having an outer surface;
wherein the first thermoplastic polymer and the second thermoplastic polymer are physically associated in a geometric arrangement, in which a flow temperature of said first thermoplastic polymer is greater than 10 degrees Celsius higher than a flow temperature of said second thermoplastic polymer,
wherein the filament or preform has a diameter of at least 1 millimeter,
wherein the cross-sectional geometry of the first thermoplastic polymer comprises a central node with three to six extending arms, where each arm has the same length and uniform thickness along its length, surrounded by the second thermoplastic polymer in the geometric arrangement,
wherein at least 90% of the outer surface is comprised of the second thermoplastic polymer, and
further wherein the filament or preform is configured to be 3D printed as multiple layers of extrudate through a nozzle using a 3D printer which accepts continuous filaments with a diameter of at least 1 mm, and the multiple layers of extrudate can be subsequently annealed above the flow temperature of the second polymer and below the flow temperature of the first thermoplastic polymer to provide an increase in the interlaminar strength between the printed multiple layers of extrudate of at least 100% after annealing.
41 . The filament or preform of claim 40 , wherein the first polymer is a propellant or explosive.
42 . A filament or preform for use in 3D printing, the filament or preform comprising a first thermoplastic polymer and a second thermoplastic polymer, the filament or preform having an outer surface;
wherein the first thermoplastic polymer and the second thermoplastic polymer are physically associated in a geometric arrangement, in which a flow temperature of said first thermoplastic polymer is greater than 10 degrees Celsius higher than a flow temperature of said second thermoplastic polymer,
wherein the cross-sectional geometry of the first thermoplastic polymer comprises a central node with five extending, where each arm has the same length and uniform thickness along its length, surrounded by the second thermoplastic polymer,
wherein at least 90% of the outer surface is comprised of the second thermoplastic polymer,
wherein the filament or preform has a diameter of at least 1 millimeter, and further wherein the filament or preform is configured to be 3D printed as multiple layers of extrudate through a nozzle using a 3D printer which accepts continuous filaments with a diameter of at least 1 mm, and the multiple layers of extrudate can be subsequently annealed above the flow temperature of the second polymer and below the flow temperature of the first thermoplastic polymer to provide an increase in the interlaminar strength between the printed multiple layers of extrudate of at least 100% after annealing.
43 . The filament or preform of claim 42 , wherein the first polymer comprises polycarbonate (PC) and the second polymer comprises acrylonitrile butadienestyrene (ABS).
44 . The filament or preform of claim 42 , wherein the geometric arrangement is selected from the group consisting of: (i) a cross-sectional geometry of the first thermoplastic polymer comprises a central node with five trapezoidal-shaped extending arms which increase in thickness as they extend from the center of the filament or preform surrounded by the second thermoplastic polymer, (ii) a cross-sectional geometry of the first thermoplastic polymer comprises a central node with five arrow-shaped extending arms pointing outwardly surrounded by the second thermoplastic polymer, (iii) a cross-sectional geometry of the first thermoplastic polymer comprises a central node with five offset rectangular-shaped extending arms surrounded by the second thermoplastic polymer, and (iv) a cross-sectional geometry of the first thermoplastic polymer comprises a central node with five extending arms having circumferentially extending tabs at their endpoints surrounded by the second thermoplastic polymer.
45 . A three dimensional object formed of multiple layers of extrudate of the filament or preform of claim 42 passed through a nozzle using a 3D printer, and optionally annealed at a temperature above the flow temperature of the second thermoplastic polymer and below the flow temperature of the first thermoplastic polymer.
46 . The three dimensional object of claim 45 , wherein the cross-sectional geometry of the extrudates of the filament or preform is substantially preserved in the object after printing and/or the optional annealing.
47 . The three dimensional object of claim 45 , wherein the object after 3D printing is subsequently annealed at a temperature above the flow temperature of the second polymer and below the flow temperature of the first thermoplastic polymer there is no apparent change in geometry of the extrudate.
48 . The three dimensional object of claim 45 , wherein having been 3D printed into an object, the multiple layers of extrudate in the have an interlaminar fracture toughness of at least 566 J/m 2 , and if subsequently annealed, the multiple layers of extrudate in the 3D printed annealed object have an interlaminar fracture toughness of at least 3970 J/m 2 .
49 . The three dimensional object of claim 45 , wherein having been 3D printed into an object and subsequently annealed, the multiple layers of extrudate of the 3D printed annealed object, exhibit an improvement in strength of at least 600% compared to the multiple layers of extrudate in the 3D printed object in an un-annealed state.
50 . The three dimensional object of claim 45 , wherein having been 3D printed into an object and subsequently annealed, the creep rate for the multiple layers of annealed extrudate at 135° C. is 1.50-2.15 μm/min.