초록 ▼

A method and apparatus are provided which enable formation of a thermoplastic article having a high volume loading of a long fiber reinforcement. The method includes providing a first thermoplastic composite material having at least about 40 volume percent of at least one reinforcing fiber; providin

A method and apparatus are provided which enable formation of a thermoplastic article having a high volume loading of a long fiber reinforcement. The method includes providing a first thermoplastic composite material having at least about 40 volume percent of at least one reinforcing fiber; providing at least one mold, the mold(s) each comprising at least one first mold section having an inlet and an outlet and defining a first mold cavity and at least one second mold section having an inlet and an outlet and defining a second mold cavity, wherein the outlet of the first mold section is in communication with the inlet of the second mold section; introducing the first thermoplastic composite material into the first mold cavity; applying heat and pressure to the first thermoplastic composite material in the first mold cavity until the first mold section reaches at least a first process temperature; releasing the pressure on the mold; and reapplying pressure to the mold while cooling, wherein at least a portion of the first thermoplastic composite material flows out of the least one outlet of the first mold section and into the second mold cavity, wherein said cooling solidifies the first thermoplastic composite to form a molded article having the shape of the second mold cavity. Articles formed from such methods and apparatus are also disclosed.

대표청구항 ▼

1. A method of forming a thermoplastic article having a long fiber reinforcement, comprising a) providing a first thermoplastic composite material having at least about 40 volume percent of at least one long reinforcing fiber and chopping or cutting the first thermoplastic composite material to form

1. A method of forming a thermoplastic article having a long fiber reinforcement, comprising a) providing a first thermoplastic composite material having at least about 40 volume percent of at least one long reinforcing fiber and chopping or cutting the first thermoplastic composite material to form a thermoplastic feed stock having discontinuous long fiber of varied lengths;b) providing at least one mold, wherein each of the at least one mold comprises at least one first mold section having a wall defining an inlet and an outlet and defining a first mold cavity andat least one second mold section having a wall defining an inlet and defining a second mold cavity, wherein the outlet of the first mold section is in communication with the inlet of the second mold section via at least one flow port;c) introducing the first thermoplastic composite material into the first mold cavity;d) applying heat and pressure to the first thermoplastic composite material in the first mold cavity until the first mold section reaches at least a first process temperature;e) releasing the pressure on the mold; andf) reapplying pressure to the mold while cooling, wherein at least a portion of the first thermoplastic composite material flows out of the outlet of the first mold section and into the second mold cavity so as to completely fill the second mold cavity with the first thermoplastic composite material, wherein said cooling solidifies the first thermoplastic composite to form a molded article having the shape of the second mold cavity and wherein the at least one long reinforcing fiber in the molded article is randomly dispersed. 2. The method according to claim 1, wherein the first thermoplastic composite material comprises a thermoplastic selected from the group consisting of polyolefins, poly(acrylonitrile-butadiene styrene), polystyrene, polybutadiene, polyacrylonitrile, poly(butadiene-styrene), poly(styrene-acrylonitrile), polybutylenes, cellulosic resins, ethylene vinyl acetates, ethylene vinyl alcohols, ionomers, liquid crystal polymers, polyacetals, polyacrylates, polyamides, polyphthalamides, polyphthalimides, polyimides, polyetheramides, polyamideimides, polyphenols, polycarbonates, polyesters, polyurethanes, polyvinyl chlorides, polyvinylidene chlorides, polyvinyls, polyesters, polyphenylene oxides, polyphenylene esters, polyphenylene ethers, polyphenylene ether esters, polyether esters, polyphenylene sulfides, polysulfones, polymethylpentenes, polyketones, polyarylene ethers, fluoropolymers, thermoplastic elastomers, epoxy resins, polybiscitraconicimides, polybismaleimides, bismaleimide/triazine/epoxy resins, polycyanate esters, cyanate resins, furanic resins, phenolic resins, urea-formaldehyde resins, melamine-formaldehyde resins, phthalocyanine resins, polybenzoxazole resins, acetylene-terminated polyimide resins, silicones, polytriazines, polyalkyds, xylene resins and copolymers, alloys, blends and derivatives thereof. 3. The method according to claim 2, wherein the thermoplastic comprises a polysulfone, a polyimide, a polyamideimide, a polyamide, or a polyarylene ether selected from the group consisting of polyether ketones, polyetherether ketones, polyetherketone ketones. 4. The method according to claim 2, wherein the thermoplastic comprises a fluoropolymer selected from the group consisting of copolymers of tetrafluoroethylene and at least one perfluoroalkylvinyl ether; copolymers of tetrafluoroethylene and at least one other perfluorinated alkylene, polychlorotrifluoroethylene, ethyl chlorotrifluoroethylene, ethyltrifluoroethylene, polyvinylidene fluoride, and polyvinyl fluoride. 5. The method according to claim 1, wherein the thermoplastic composite material comprises a thermoplastic is selected from polyetherether ketone, polyether ketone, polyether ketone ketone, copolymers of tetrafluoroethylene and at least one perfluoroalkylvinyl ether, and copolymers of tetrafluoroethylene and hexafluoropropylene. 6. The method according to claim 1, wherein the at least one reinforcing fiber is in the molded article is discontinuous long fiber. 7. The method according to claim 6, wherein the at least one reinforcing fiber comprises a fiber selected from the group consisting of inorganic fibers, ceramic fibers, glass fibers, graphite fibers, carbon fibers, thermoplastic fibers and/or thermosetting fibers. 8. The method according to claim 1, wherein step (a) further comprises chopping or cutting a continuous long fiber-reinforced composite into a plurality of sections having discontinuous long fiber. 9. The method according to claim 8, wherein the continuous long fiber-reinforced composite is a continuous long fiber-reinforced tape. 10. The method according to claim 8, wherein the plurality of sections having discontinuous long fiber have at least two different lengths measured in the longitudinal dimension of the section. 11. The method according to claim 1, wherein the first thermoplastic composite has at least about 50 volume percent of the at least one reinforcing fiber. 12. The method according to claim 11, wherein the first thermoplastic composite has at least about 60 volume percent of the at least one reinforcing fiber. 13. The method according to claim 1, wherein the method further comprises placing the mold into a heated press, and pressing downward upon the first thermoplastic composite material when it is in the first mold cavity using a ram or piston inserted into the inlet of the first mold section, wherein the heated press drives the ram or piston into the first mold cavity. 14. The method according to claim 1, wherein the first thermoplastic composite material is heated by heating the mold under pressure in step (d) to about 750° F. to about 900° F. until the first process temperature is achieved. 15. The method according to claim 14, wherein the mold is heated under pressure in step (d) to about 825° F. to about 875° F. 16. The method according to claim 14, wherein the first process temperature is about 750° F. to about 780° F. 17. The method according to claim 16, wherein the pressure is about 2,000 psi to about 5,000 psi. 18. The method according to claim 1, further comprising applying pressure to the first thermoplastic composite material in step (d) by placing the mold in a heated press at a pressure of about 1,000 psi to about 10,000 psi. 19. The method according to claim 1, wherein after releasing the pressure on the mold in step (e), the method further comprises placing the mold in a cooling press. 20. The method according to claim 19, wherein the cooling press applies pressure to the mold while cooling in step (f) of about 1,000 psi to about 10,000 psi. 21. The method according to claim 20, wherein the cooling press applies pressure to the mold while cooling in step (f) of about 2,000 psi to about 5,000 psi. 22. The method according to claim 1, wherein the mold has a plurality of flow ports. 23. The method according to claim 1, wherein step (f) comprises cooling the first thermoplastic material in the second mold cavity to a handling temperature. 24. The method according to claim 1, further comprising removing the molded article from the second mold cavity. 25. The method according to claim 1, wherein the second mold cavity comprises at least one molding fitting. 26. A method of forming a thermoplastic article having a long fiber reinforcement, comprising a) providing a first thermoplastic composite material having at least about 40 volume percent of at least one long reinforcing fiber and chopping or cutting the first thermoplastic composite material to form a thermoplastic feed stock having discontinuous long fiber of varied lengths;b) providing at least one mold, wherein each of the at least one mold comprises at least one first mold section having a wall defining an inlet and an outlet and defining a first mold cavity andat least one second mold section having a wall defining an inlet and defining a second mold cavity, wherein the outlet of the first mold section is in communication with the inlet of the second mold section via at least one flow port defined by the at least one mold wall so as to extend between the outlet of the first mold section and the inlet of the second mold section;c) introducing the first thermoplastic composite material into the first mold cavity;d) applying heat and pressure to the first thermoplastic composite material in the first mold cavity until the first mold section reaches at least a first process temperature;e) releasing the pressure on the mold; andf) reapplying pressure to the mold while cooling, wherein at least a portion of the first thermoplastic composite material flows out of the outlet of the first mold section and into the second mold cavity, wherein said cooling solidifies the first thermoplastic composite to form a molded article having the shape of the second mold cavity and wherein the at least one long reinforcing fiber in the molded article is randomly dispersed. 27. A method of forming a thermoplastic article having a long fiber reinforcement, comprising providing a first thermoplastic composite material having at least about 40 volume percent of at least one long reinforcing fiber and chopping or cutting the first thermoplastic composite material to form a thermoplastic feed stock having discontinuous long fiber of varied lengths;providing at least one mold, wherein each of the at least one mold comprises at least one first mold section having a wall defining an inlet and an outlet and defining a first mold cavity andat least one second mold section having a wall defining an inlet and defining a second mold cavity, wherein the outlet of the first mold section is in communication with the inlet of the second mold section via at least one flow port;introducing the first thermoplastic composite material into the first mold cavity;applying heat and pressure to the first thermoplastic composite material in the first mold cavity until the first mold section reaches at least a first process temperature;applying pressure to the mold while cooling, wherein at least a portion of the first thermoplastic composite material flows out of the outlet of the first mold section and into the second mold cavity so as to completely fill the second mold cavity with the first thermoplastic composite material, wherein said cooling solidifies the first thermoplastic composite to form a molded article having the shape of the second mold cavity and wherein the at least one long reinforcing fiber in the molded article is randomly dispersed. 28. The method according to claim 27, wherein the molded first thermoplastic composite material in the article is a solid thermoplastic composite material shaped by the second mold cavity. 29. The method of claim 27, wherein the second mold cavity comprises at least one molding fitting. 30. A method of forming a thermoplastic article having fiber reinforcement, comprising: a) providing a first thermoplastic composite material having at least about 40 volume percent of at least one reinforcing fiber, wherein the first thermoplastic composite material is prepared by chopping or cutting a continuous long fiber-reinforced composite into a plurality of sections;b) providing at least one mold, wherein each of the at least one mold comprises at least one first mold section having a wall defining an inlet and an outlet and defining a first mold cavity andat least one second mold section having a wall defining an inlet and defining a second mold cavity, wherein the outlet of the first mold section is in communication with the inlet of the second mold section via at least one flow port;c) introducing the chopped or cut plurality of sections of the first thermoplastic composite material into the first mold cavity;d) applying heat and pressure to the first thermoplastic composite material in the first mold cavity until the first mold section reaches at least a first process temperature;e) releasing the pressure on the mold; andf) reapplying pressure to the mold while cooling, wherein at least a portion of the first thermoplastic composite material flows out of the outlet of the first mold section and into the second mold cavity so as to completely fill the second mold cavity with the first thermoplastic composite material, wherein said cooling solidifies the first thermoplastic composite to form a molded article having the shape of the second mold cavity and wherein the at least one reinforcing fiber in the molded article is randomly dispersed. 31. The method according to claim 30, wherein the continuous long fiber-reinforced composite is a continuous long fiber-reinforced tape. 32. The method according to claim 30, wherein the plurality of sections having discontinuous fiber have at least two different lengths measured in the longitudinal dimension of the section. 33. The method according to claim 30, wherein the first thermoplastic composite has at least about 50 volume percent of the at least one reinforcing fiber. 34. The method according to claim 33, wherein the first thermoplastic composite has at least about 60 volume percent of the at least one reinforcing fiber.