Fiber molding preform composition and process for preform formation
View Patent ↗A preform for thermoset resin composition molding is provided that upon cure forms a variety of molded and fiber reinforced articles used in a variety of applications such as vehicle components including bed lines, body components, trim, interior components, and undercar components; architectural components such as trim and doors, marine components including hulls, trim, and cockpit pieces; and similar structures in aerospace settings. A novel slurry composition, a novel centrifugal process, or a combination thereof provide superior quality preforms that are created with greater throughput relative to conventional techniques. The inhibition of fiber movement between the time such a fiber contacts the mold, or fibers already in place on the mold, and the time the fibers are set in position provides a superior fiber homogeneity and randomized orientation relative to existing slurry techniques with attributes of low scrap generation, and process flexibility with respect to part shape and fiber material.
1. A process for producing a plurality of vehicle component preforms in a single run, said process comprising:
inserting a plurality of solvent porous preform molds into a series of slots formed in a basket of a centrifuge;
rotating said basket within a stationary housing;
metering a slurry containing a solvent and fibers onto a surface of each of said preform molds to draw said solvent through said preform molds and retain said fibers on the surface;
applying a material to said preform molds or said plurality of vehicle component preforms from a reservoir separate from said slurry; and
drying said preform molds until said fibers are dry to define said vehicle component plurality of preforms each having a preselected preform strength.
2. The process of claim 1 wherein the slurry is metered through a manifold of apertures.
3. The process of claim 2 wherein the apertures vary in area as a function of distance from a tank containing said slurry.
4. The process of claim 1 further comprising drawing a vacuum external to said basket of said centrifuge.
5. The process of claim 1 wherein drying is with at least one of hot air, resistive heating and radiation.
6. The process of claim 1 wherein said plurality of solvent porous preform molds are slidably inserted into said series of slots formed in said basket.
7. The process of claim 1 further comprising removing said plurality of solvent porous preform molds from said basket and further heating said preforms thereon remote from said centrifuge.
8. The process of claim 1 wherein said slurry is applied to said mold in a first region at a first fiber density and in a second region at a second fiber density that varies from the first fiber density.
9. The process of claim 1 wherein the material is a binder.
10. The process claim 1 wherein the material is a filler.
11. The process of claim 10 wherein the filler is hollow glass microspheres.
12. The process of claim 10 wherein the filler is paramagnetic filler.
13. The process of claim 1 wherein the material is a glutaraldehyde and protein is present in said slurry.
14. The process of claim 1 wherein the material is a pretreatment agent and said fibers are natural cellulosic fibers.
15. The process of claim 1 wherein the material is an activating agent reactive with hydroxyl groups in the preform.
16. The process of claim 15 wherein said activating agent is a silane and the hydroxyl groups are on at least one of said fibers or glass microspheres.
17. The process of claim 16 wherein said fibers are glass fibers.
18. The process of claim 16 wherein said fibers are natural cellulosic fibers.
19. The process of claim 13 wherein said activating agent is one of 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, (3-glycidoxypropyl)bis(trimethylsiloxy)methylsilane, (3-glycidoxypropyl)methyldiethoxysilane, (3-glycidoxypropyl)dimethylethoxysilane, (3-glycidoxypropyl)methyldimethoxysilane, methacryloxymethyltriethoxysilane, methacryloxymethyltrimethoxysilane, methacryloxypropyldimethylethoxysilane, methacryloxypropyldimethylmethoxysilane, ethacryloxypropylmethyldimethoxysilane, methacryloxypropyltriethoxysilane, methoxymethyltrimethylsilane, 3-methoxypropyltrimethoxysilane, 3-methacryloxypropyldimethylchlorosilane, methacryloxypropylmethyldichlorosilane, methacryloxypropyltrichlorosilane, 3-isocyanatopropyldimethylchlorosilane, 3-isocyanatopropyltriethoxysilane, or bis(3-triethoxysilylpropyl)tetrasulfide.
20. The process of claim 1 wherein drying said preform molds is accomplished by a dryer positioned within said basket of said centrifuge.
21. The process of claim 1 further comprising removing said preforms from said centrifuge by removing said plurality of solvent porous preform molds.
22. The process of claim 1 wherein said plurality of vehicle component performs are the same shape and form one of a bed liner, a body component, trim, an interior component, an undercar component, or a door.