Abstract: A thermoplastic filament or preform comprising a thermoplastic liquid crystal polymer (TLCP) is described. It can be incorporated into threads with one or more thermoplastics, where this filament can be used in 3D printing to produce parts that are stiffer and stronger than conventional 3D printed polymers. In one particularly advantageous embodiment, the TLCP is a multi-fiber core that is surrounded by a continuous solid polymer sheath. Also described are unique processing methods for manufacturing these TLCP-containing filaments.

Abstract: We disclose dual filament-based flexible material extrusion which is suitable of additive manufacturing for of at least two thermoplastic elastomers. To enhance printability of a thermoplastic elastomer (TPE), a series of core-shell filaments comprising a TPE shell and a rigid core are fabricated, such as ABS with the ABS volume fraction varying from 11% to 78%, in one particular embodiment. The presence of an ABS core imparts rigidity to the filament to inhibit buckling and allow for successful high-fidelity 3D printing. Rheological characterizations of TPE and ABS using capillary and parallel-plate viscometry point to the optimized extrusion parameters suitable for filament coextrusion, printability, and wettability between the print interfaces. Printed specimens with less than 20% ABS preserve the hardness, providing flexibility and a soft touch to the printed structures. Lower ABS content exhibits higher flexibility and impact resistance, while higher ABS imparts higher stiffness and tensile strength.

Abstract: A polymer body includes a first thermoplastic polymer, and a second thermoplastic polymer. The first thermoplastic polymer and the second thermoplastic polymer form a continuous solid structure. The first thermoplastic polymer forms an external supporting structure that at least partially envelops the second thermoplastic polymer. A first flow temperature of the first thermoplastic polymer is at least 10° C. higher than a second flow temperature of the second thermoplastic polymer. The first thermoplastic polymer may be removable by exposure to a selective solvent.

Abstract: A polymer body includes a first thermoplastic polymer, and a second thermoplastic polymer. The first thermoplastic polymer and the second thermoplastic polymer form a continuous solid structure. The first thermoplastic polymer forms an external supporting structure that at least partially envelops the second thermoplastic polymer. A first flow temperature of the first thermoplastic polymer is at least 10° C. higher than a second flow temperature of the second thermoplastic polymer. The first thermoplastic polymer may be removable by exposure to a selective solvent.

Abstract: 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.

Abstract: A polymer body includes a first thermoplastic polymer, and a second thermoplastic polymer. The first thermoplastic polymer and the second thermoplastic polymer form a continuous solid structure. The first thermoplastic polymer forms an external supporting structure that at least partially envelops the second thermoplastic polymer. A first flow temperature of the first thermoplastic polymer is at least 10° C. higher than a second flow temperature of the second thermoplastic polymer. The first thermoplastic polymer may be removable by exposure to a selective solvent.