Fiber reinforced composites and method for their manufacture
First Claim
1. Method of manufacturing fiber reinforced composites comprising the steps of forming a nonwoven batt from structural fibers and a thermoplastic binder material, orienting the fibers as the batt is formed so that a substantial portion of the fibers interlock randomly with other fibers in the mat in each of the three spatial dimensions, molding the batt while heating the batt to a termperature to at least partially melt the binder material to form the batt into a shape-retaining preform of the desired configuration and injecting the preform with a resin matrix to fill the interstices between the fibers.
2 Assignments
0 Petitions
Accused Products
Abstract
A fiber reinforced, composite article is manufactured by forming a nonwoven, air-laid batt from a single fiber type or a mixture of fibers. The batt is either resinated with a thermoplastic material or includes a thermoplastic binder fiber. The batt is formed into a preform having the desired shape in a through-air mold and heated sufficiently to set the thermoplastic material, so that the resulting preform retains the desired shape and is sufficiently stiff to withstand the pressure of the injected resin. The preform is then transferred to a resin injection mold, where the interstices between the fibers are saturated with an appropriate resin matrix. As the fibers of the preform are saturated (or after a saturation but before the resin sets) the resin transfer mold is compressed, thereby forming the preform into its final desired thickness and increasing the concentration of the fibers to give the preform appropriate strength. Accordingly, the preform retains the open characteristics permitting easy injection of the resin, while later being compressed to increase the concentration of the reinforcing fibers to give the resulting composite the appropriate strength.
107 Citations
28 Claims
- 1. Method of manufacturing fiber reinforced composites comprising the steps of forming a nonwoven batt from structural fibers and a thermoplastic binder material, orienting the fibers as the batt is formed so that a substantial portion of the fibers interlock randomly with other fibers in the mat in each of the three spatial dimensions, molding the batt while heating the batt to a termperature to at least partially melt the binder material to form the batt into a shape-retaining preform of the desired configuration and injecting the preform with a resin matrix to fill the interstices between the fibers.
- 14. Method of manufacturing fiber reinforced composites comprising the steps of forming an air-laid nonwoven batt including structural fibers and a thermoplastic binder material, transferring a section of the batt to a preform mold, molding said batt section into a desired preform in the preform mold, transferring the preform to a resin transfer mold, injecting the preform with a resin matrix to fill the interstices between the fibers, and removing the article from the mold after the resin has cured sufficiently to permit handling.
- 22. Fiber reinforced composite acticle comprising a batt of nonwovern structured fibers, said fibers being randomly arranged and interlocked with one another in each of the three spatial dimensions, said batt including a thermoplastic material which has been heated to a temperature sufficient to at least partially melt the thermoplastic material and thus at least partially fuse the staple structural fibers to one another, and a cured resin matrix filling the interstices between the fibers.
Specification