Impact-resistant articles and methods for making the same
A method of manufacturing an impact-resistant material is described. Embodiments of the method includes hydrating a reinforcing material, which can be, for example, a fabric comprised of para-aramid fiber, infusing the hydrated reinforcing material with a resin, and curing the infused reinforcing material. Certain embodiments include hydrating the reinforcing material by exposing the reinforcing material to humidity and infusing the material by with a prepolymer-based diisocynate, for example, methylene diphenyl 4, 4′diisocyanate.
1. A method of manufacturing impact-resistant material, the method comprising:
hydrating a reinforcing material, the reinforcing material comprising a fabric;
infusing the reinforcing material, while the reinforcing material is in a hydrated state, with a prepolymer-based diisocyanate; and
curing the infused reinforcing material.
2. The method of claim 1 wherein the hydrating step comprises exposing the reinforcing material to humidity.
3. The method of claim 1 further comprising regulating the hydration of the hydrated reinforcing material to obtain a retained moisture content of less than about 2 percent by weight of the reinforcing material.
4. The method of claim 1 further comprising regulating the hydration of the hydrated reinforcing material to obtain a retained moisture content of about 2 percent by weight to about 3 percent by weight of the reinforcing material.
5. The method of claim 3 wherein the regulating step comprises vacuum bagging the hydrated reinforcing material.
6. The method of claim 5 wherein the regulating step comprises:
enclosing the hydrated reinforcing material in a vacuum bag;
evacuating the vacuum bag to a predetermined vacuum; and
maintaining the predetermined vacuum in the vacuum bag.
7. The method of claim 6 wherein the evacuating step comprises evacuating the vacuum bag to at least about 25 bar.
8. The method of claim 1 wherein the infusing step comprises infusing the reinforcing material with the prepolymer-based diisocyanate so that the impact-resistant material comprises from about 70percent to about 95 percent by weight reinforcing material.
9. The method of claim 1 wherein the curing step comprises applying pressure to the infused reinforcing material.
10. The method of claim 9 wherein the applying pressure step further comprises:
increasing pressure to the infused reinforcing material to a first pressure;
maintaining the first pressure for a period of time; and
increasing the pressure to a second pressure.
11. The method of claim 9 wherein the applying pressure step further comprises applying pressure to the infused reinforcing material to at least about 200 tons per square foot.
12. The method of claim 9 further comprising:
maintaining the pressure at a desired level; and
applying heat to the infused reinforcing material.
13. The method of claim 1 wherein the fabric comprises para-aramid fibers.
14. The method of Claim 1 wherein the fabric is a woven or a non-woven fabric.