Multi-material polymer filament for three-dimensional printing co-drawn with functional or structural thread

Patent metadata

Field	Value
Publication number	US-2018087189-A1
Application number	US-201715630175-A
Country	US
Kind code	A1
Filing date	Jun 22, 2017
Priority date	Mar 27, 2015
Publication date	Mar 29, 2018
Grant date	—

Abstract

A thermoplastic filament comprising multiple polymers of differing flow temperatures in a geometric arrangement and an interior channel containing a structural or functional thread therein 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 an interior thread contained within the outer, printed filament or fiber. This thread adds structural reinforcement or functional properties, such as electrical conductivity or optical waveguiding, to the filament.

First claim

We claim:

1 . A filament or preform comprising at least a first thermoplastic polymer and a second thermoplastic polymer, the first thermoplastic polymer and the second thermoplastic polymer physically associated in a geometric arrangement
said filament or preform further comprising at least one orifice extending the length of said filament or preform and a thread comprising a third material that is different from said first thermoplastic polymer and said second thermoplastic polymer disposed in said orifice in said filament or preform.

2 . The filament or preform of claim 1 wherein said filament or preform is printed.

3 . The filament or preform of claim 1 , where said thread is an optical fiber.

4 . The filament or preform of claim 3 , where said thread is made of glass.

5 . The filament or preform of claim 3 , where said thread is made of polymer.

6 . The filament or preform of claim 5 , wherein said thread is made of a thermoplastic with a flow temperature at least 20 degrees Celsius higher than the higher of the flow temperature of said first thermoplastic polymer and the flow temperature of said second thermoplastic polymer.

7 . The filament or preform of claim 1 , wherein said thread is electrically conductive.

8 . The filament or preform of claim 7 , wherein said thread is a stranded or solid metal wire.

9 . The filament or preform of claim 8 , wherein said thread comprises copper, tungsten, a steel, aluminum, a shape memory alloy, lead, titanium, brass, nickel, bronze or an alloy, mixture or composite thereof.

10 . The filament or preform of claim 1 , wherein said thread has a tensile stiffness greater than 1 GPa.

11 . The filament or preform of claim 10 , wherein said thread comprises carbon fiber, glass fiber, alumina fiber, poly(p-phenylene terephthalamide) fiber, polyoxazole fiber, liquid crystalline aromatic polyester thermoplastic fiber, ultra-high molecular weight polyethylene fiber, nylon fiber, spider silk, or carbon nanotube fibers.

12 . The filament or preform of claim 1 , wherein said preform is printed in a regular geometric arrangement.

13 . A filament or preform comprising a first thermoplastic polymer and a second thermoplastic polymer, the first thermoplastic polymer and the second thermoplastic polymer physically associated in a geometric arrangement
said filament or preform further comprising at least one orifice extending the length of said filament or preform and a discontinuous thread comprising a third material that is different from said first thermoplastic polymer and said second thermoplastic polymer disposed in said orifice in said filament or preform.

14 . The filament or preform of claim 13 wherein said filament or preform is printed.

15 . The filament or preform of claim 13 , wherein said thread is staple yarn.

16 . The filament or preform of claim 15 , wherein said thread is a stretch-broken yarn.

17 . The filament or preform of claim 13 , wherein said thread is an collection of individual fibers with individual lengths less than 50 mm, and fiber tensile stiffness of at least 1 GPa.

18 . The filament or preform of claim 17 , wherein said thread comprises carbon fiber, glass fiber, alumina fiber, poly(p-phenylene terephthalamide) fiber, polyoxazole fiber, liquid crystalline aromatic polyester thermoplastic fiber, ultra-high molecular weight polyethylene fiber, nylon fiber, spider silk, carbon nanotube fibers or mixtures thereof.

19 . The filament or preform of claim 15 , wherein said thread is a natural staple fiber.

20 . The filament or preform of claim 19 , wherein said thread is cotton, wool, flax, bamboo, cellulose or hair.

21 . A process for creating a polymer filament, said process comprising:
associating a first thermoplastic polymer and a second thermoplastic polymer in a geometric arrangement to create a preform having at least one orifice extending the length of said filament; inserting a thread comprising a material that is different from said first thermoplastic polymer and said second thermoplastic polymer in said at least one orifice extending the length of said filament or preform; heating said preform to a drawing temperature; and pulling said preform under tension to draw said preform down to a filament such that said geometric arrangement is preserved and said thread is included within said at least one orifice extending the length of said filament.

22 . The process of claim 21 , further comprising the step of manufacturing said first thermoplastic polymer, said second thermoplastic polymer, or both by three-dimensional printing.

23 . The process of claim 21 , wherein said thread is made of a thermoplastic with a flow temperature at least 20 degrees Celsius higher than the higher of the flow temperature of said first thermoplastic polymer and the flow temperature of said second thermoplastic polymer.

24 . The process of claim 21 , wherein said thread is an optical fiber.

25 . The process of claim 21 , wherein said thread material is glass.

26 . The process of claim 21 , wherein said thread is electrically conductive.

27 . The process of claim 21 , wherein said thread is a metal fiber.

28 . The process of claim 21 , wherein said thread has a tensile stiffness greater than 1 GPa.

29 . The process of claim 21 , wherein said thread comprises a staple yarn.

30 . The process of claim 21 , wherein said thread comprises carbon fiber, glass fiber, alumina fiber, poly(p-phenylene terephthalamide) fiber, polyoxazole fiber, liquid crystalline aromatic polyester thermoplastic fiber, ultra-high molecular weight polyethylene fiber, nylon fiber, spider silk, carbon nanotube fibers, cotton, wool, flax, bamboo, cellulose or hair.

31 . A process for creating a polymer filament, said process comprising:
heating one or more polymer feedstocks; depositing said polymer feedstocks to create, layer-by-layer, a three-dimensional preform comprising two or more polymers in a geometric arrangement having at least one orifice extending the length of said filament; inserting a thread comprising a material that is different from said first thermoplastic polymer and said second thermoplastic polymer in said at least one orifice extending the length of said filament or preform; heating said preform to a drawing temperature; and pulling said preform under tension to draw said preform down to a filament such that said geometric arrangement is preserved and said thread is included within said at least one orifice extending the length of said filament.

32 . A device for creating a filament, said device comprising:
heating elements for heating one or more polymer feedstocks above their flow temperature; a deposition system for depositing said polymer feedstocks to create, layer-by-layer, a three-dimensional preform comprising two or more polymers in a regular geometric arrangement; an oven for heating said preform to a drawing temperature; and a take-up mechanism to pull said preform under tension and draw said preform down to a filament such that said regular geometric arrangement is preserved.

33 . A device for creating a filament, said device comprising:
heating elements for heating one or more polymer feedstocks above their flow temperature; a deposition

Assignees

• U S Army Res Laboratory Attn Rdrl Loc I

Inventors

• Wetzel Eric D
• Holmes Jr Larry R
• Rodriguez Ricardo X
• Toal Jr Patrick M

Classifications

• B29C64/106 Primary

  using only liquids or viscous materials, e.g. depositing a continuous bead of viscous material · CPC title

• B29K2105/08

  of continuous length, e.g. cords, rovings, mats, fabrics, strands or yarns · CPC title

• B29C35/02

  Heating or curing, e.g. crosslinking or vulcanizing {during moulding, e.g. in a mould}(cold vulcanisation B29C35/18 {; vulcanising tyres, presses therefor B29D30/0601}) · CPC title

• D01F8/18

  from other substances · CPC title

• B29K2069/00

  Use of PC, i.e. polycarbonates {or derivatives thereof}, as moulding material · CPC title