Brown, Bari W.; Ireland, Steven P.;

Fiber choppers for molding processes

This process and apparatus use at least one chopper unit. The fiber choppers may be laser beam choppers or existing standard chopper units. The process and apparatus for producing a fiber-reinforced molded composite comprises providing a moldable composition, sequentially spraying a moldable composition into the mold, subsequently providing chopped fibers to the moldable composition and depositing the moldable composition and chopped fibers in mold and molding the moldable composition and fibers in the apparatus under heat and pressure to form the molded composite. One industrial application for these choppers is compression molding of interior trim panels for automobile doors. The choppers spray chopped glass fiber strands into a resin mixture. The glass and a polyol, isocyanate (--NCO) urethane resin mixture at the proper glass loading, distribution and pattern is fed to the mold.

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We claim:

1. A process for producing a fiber-reinforced molded composite comprising the steps of:

providing a mold;

sequentially first spraying a moldable composition into the mold from a nozzle;

subsequently providing chopped fibers to the moldable composition from a single fiber chopper;

depositing the moldable composition and chopped fibers in mold; and

molding the moldable composition and fibers in the mold under heat and compression to form the molded composite.

2. A process according to claim 1 wherein the nozzle for spraying the moldable composition and the single fiber chopper make at least one pass over the mold and wherein the nozzle leads the fiber chopper in each pass.

3. A process according to claim 3 wherein the nozzle always leads the fiber chopper in each pass.

4. A process according to claim 1 wherein the nozzle and single fiber chopper make repeated passes over the mold.

5. A process according to claim 1 wherein the nozzle is sandwiched between the single fiber chopper and a second fiber chopper, wherein one of the choppers is a lead chopper and one of the choppers is a trailing chopper in each pass, wherein the lead chopper is turned off and the trailing chopper is turned on during each pass.

6. A process according to claim 1 wherein the nozzle first deposits the moldable composition into the mold and then deposits a blend of the fiber and the moldable composition into the mold.

7. A process according to claim 1 wherein the nozzle sprays a polyurethane mixture of a polyol and an isosyanate and the fiber chopper provides chopped glass fibers.

8. A process according to claim 1 wherein a fluid discharge block propels the chopped fibers from the single fiber chopper.

9. A process according to claim 1 wherein the chopped fibers are dispersible and have ends that disperse in a fiber, resin spray-up process.

10. An apparatus for producing a fiber-reinforced molded composite comprising:

a mold including a means for heating and compressing the mold;

a means for providing a moldable composition to the mold including a nozzle for spraying the moldable composition into the mold;

a single fiber chopper for providing chopped fibers to the mold; and

a programmable multi-axis robot including a cantilevered overhead arm with a mounting plate attached to a distal end of the arm;

wherein the nozzle and fiber chopper are attached to the mounting plate and aligned sequentially so that the nozzle first sprays moldable composition into the mold and the chopper subsequently provides chopped fibers to the moldable composition.

11. An apparatus according to claim 10 including a programmed microprocessor configured to first spray the moldable composition into the mold and subsequently deposit the moldable composition and chopped fibers into the mold.

12. An apparatus according to claim 10 wherein the microprocessor is configured to move the nozzle for spraying the moldable composition and the single fiber chopper to make at least one pass over the mold and make the nozzle always lead the fiber chopper on each pass.

13. An apparatus according to claim 10 wherein the microprocessor is configured to move the nozzle and single fiber chopper to make repeated passes over the mold.

14. An apparatus according to claim 10 wherein the nozzle is sandwiched between the single fiber chopper and a second fiber chopper, wherein one of the choppers is a lead chopper and one of the choppers is a trailing chopper in each pass; and

wherein the microprocessor is configured to turn off the lead chopper and configured to turn on the trailing chopper during each pass.