High strength, long durability structural fabric/seam system
View Patent ↗A high strength, high modulus structural fabric product and the method of manufacturing the product are disclosed. The incorporation of a specific fiber/fabric treatment coupled with a resin impregnation and coating process produces a composite material. This composite material comprises high strength and modulus fibers embedded in and linked to a matrix. The resulting fabric product is useable in the formation of seamed structures, which carry and distribute high-level loads under extreme environmental conditions.
1. A radome comprising:
a fabric layer having a plurality of high strength and high modulus fibers, the plurality of fibers impregnated by an impregnation compound with the fabric layer coated on each side with the impregnation compound, where the impregnation compound is derived from a mixture comprising:
a pre-polymer having an isocynate having an equivalent weight of 42 and an isocynate content of 6.34;
a co-reactant curative having an equivalent weight of 230; and
a diluent solvating the mixture of the pre-polymer and the curative, and
wherein the impregnation compound has a curative stoichiometry range of less than 85 percent, and
wherein the high strength and high modulus fibers comprise at least one of aramid fibers or aromatic polyester fibers.
2. The radome of claim 1 , further comprising a thermally-welded seam, wherein the thermally-welded seam comprises the fabric product.
3. The radome of claim 2 wherein the thermally-welded seam has a strength to withstand an applied force of 880 pounds per square inch for at least 56 hours.
4. The radome of claim 1 wherein the aramid fibers comprise polyaramid polyparaphenylene terephthalamide fibers.
5. The radome of claim 1 wherein the aromatic polyester fibers comprise polyester-polyarylate fibers.
6. The radome of claim 1 wherein the impregnation compound has a curative stoichiometry range of approximately 75 percent.
7. The radome of claim 6 wherein a ratio of the co-reactant to the pre-polymer is about 26.1 to 100.0.
8. The radome of claim 7 wherein the ratio of the curative to the pre-polymer is about 26 parts by weight of curative per 100 parts of pre-polymer.
9. The radome of claim 1 wherein the pre-polymer comprises a urethane pre-polymer.
10. The radome of claim 1 wherein the diluent comprises a solvent.
11. A radome comprising:
a thermally-welded seam comprising a fabric layer, the fabric layer having a plurality of high strength and high modulus fibers, the plurality of fibers impregnated by an impregnation compound with the fabric layer coated on each side with the impregnation compound, where the impregnation compound is derived from a mixture comprising:
a pre-polymer comprising an isocynate having an equivalent weight of 42, the pre-polymer having an isocynate content of 6.34;
a co-reactant curative having an equivalent weight of 230; and
a diluent solvating the mixture of the pre-polymer and the curative, and
wherein the impregnation compound has a curative stoichiometry range of approximately 75 percent,
wherein the high strength and high modulus fibers comprise at least one of aramid fibers or aromatic polyester fibers,
wherein the ratio of the curative to the pre-polymer is derived from the formula:
6.34
×
0.75
×
230
42
=
parts
by
weight
of
curative
per
100
parts
of
pre
-
polymer
,
where 6.34 is the isocynate content of the pre-polymer, 0.75 is the stoichiometry range of the mixture, 230 is the equivalent weight of the curative and 42 is the equivalent weight of the isocynate.
12. The radome of claim 11 wherein the pre-polymer comprises a urethane pre-polymer.
13. The radome of claim 11 wherein the diluent comprises a solvent.
14. The radome of claim 11 wherein the thermally-welded seam has a strength to withstand an applied force of 880 pounds per square inch for at least 56 hours.
15. The radome of claim 11 wherein the aramid fibers comprise polyaramid polyparaphenylene terephthalamide fibers.
16. The radome of claim 11 wherein the aromatic polyester fibers comprise polyester-polyarylate fibers.
17. A radome comprising
a fabric product comprising at least one resin fabric piece, the resin fabric piece comprising:
a resin impregnated fabric layer comprising high strength and high modulus fibers and having a resin impregnated therein;
a first resin layer having a resin disposed on a first side of the resin impregnated fabric layer; and
a second resin layer having a resin disposed on a second side of the resin impregnated fabric layer, wherein the resin is derived from a mixture comprising:
a pre-polymer comprises an isocynate having an equivalent weight of 42, the pre-polymer having an isocynate content of 6.34;
a co-reactant curative having an equivalent weight of 230; and
a diluent solvating the mixture of the pre-polymer and the curative, and wherein the impregnation compound has a curative stoichiometry range of approximately 75 percent,
wherein the high strength and high modulus fibers comprise at least one of aramid fibers or aromatic polyester fibers;
wherein the resin has a ratio of the curative to the pre-polymer in accordance with the formula:
6.34
×
0.75
×
230
42
=
parts
by
weight
of
curative
per
100
parts
of
pre
-
polymer
,
where the pre-polymer comprises an isocynate and where 6.34 is the isocynate content of the pre-polymer, 0.75 is the desired stoichiometry of the mixture, 230 is the equivalent weight of the curative and 42 is the equivalent weight of the isocynate.
18. The radome of claim 17 , further comprising a thermally-welded seam, wherein the thermally-welded seam comprises the fabric product, and
wherein the thermally-welded seam has a strength to withstand an applied force of 880 pounds per square inch for at least 56 hours.
19. The radome of claim 17 wherein the aramid fibers comprise polyaramid polyparaphenylene terephthalamide fibers, and
wherein the aromatic polyester fibers comprise polyester-polyarylate fibers.
20. The radome of claim 17 , further comprising a second resin fabric piece disposed along a surface of the second resin layer, the second resin fabric piece being substantially the same as the first resin fabric piece.