Three-dimensional spacer fabric resin interlaminar infusion media process and vacuum-induced reinforcing composite laminate structures
A three-dimensional spacer fabric resin interlaminar infusion medium and reinforcing composite lamina for use in the vacuum-induced manufacture of fiber reinforced polymer composites is described. This use of the three-dimensional spacer fabric as a composite interlaminar component improves both the vacuum-induced resin infusion flow rate and laminate quality control and aids in the achievement of enhanced resin uniformity distribution throughout the laminate.
1. A method for the vacuum-induced fabrication of reinforced plastic composites comprising:
assembling a fiber structure including a three-dimensional fibrous spacer fabric employed as an interlamina infusion medium, said fabric having at least first and second outer substantially fibrous layer surfaces composed of fibers or yarns, each of said outer layers being generally oriented in an X–Y plane, said spacer fabric having between its outer layers an intermediate spacer layer composed of spacer fibers or yarns oriented in a generally transverse direction with respect to said X–Y planes of said outer layers,
juxtapositioning said spacer fabric with respect to at least one mold surface of a desired shape and configuration,
forming an assembly comprising a substantially gas impervious cover sheet substantially enclosing said fabric,
applying a negative pressure to said assembly, which collapses said spacer fabric,
introducing a liquid resin flow within and into said collapsed spacer fabric while under negative pressure,
continuing said resin flow to said collapsed spacer fabric so as to substantially fully saturate said spacer fabric with resin,
terminating the resin flow, and
thereafter allowing the resin to cure, with said spacer fabric in the collapsed state.
2. The method of claim 1 wherein said fiber structure further comprises at least one additional fibrous layer on at least one of said outer surfaces of said spacer fabric.
3. The method of claim 1 wherein said fiber structure further comprises at least one additional fibrous layer on each of said outer surfaces of said spacer fabric.
4. The method of claim 2 wherein said spacer fabric and said at least one additional fibrous layer are assembled together by stitching or knitting.
5. The method of claim 3 wherein said spacer fabric and said additional fibrous layers are assembled together by stitching or knitting.
6. The method of any one of claims 1 , 2 , 3 , 4 , or 5 wherein said spacer fabric has an initial thickness of from about 2 mm to about 25 mm.
7. The method of claim 1 wherein said negative pressure is applied at a first location of said assembly, and said resin flow is introduced to a different, second location of said assembly, and wherein said resin flows from said first location toward said second location, so as to gradually saturate said spacer fabric with resin.
8. The method of claim 7 wherein said fiber structure further comprises at least one additional fibrous layer on at least one of said outer surfaces of said spacer fabric.
9. The method of claim 7 wherein said fiber structure further comprises at least one additional fibrous layer on each of said outer surfaces of said spacer fabric.
10. The method of claim 8 wherein said spacer fabric and said at least one additional fibrous layer are assembled together by stitching or knitting.
11. The method of claim 9 wherein said spacer fabric and said additional fibrous layers are assembled together by stitching or knitting.
12. The method of any one of claims 7 , 8 , 9 , 10 or 11 wherein said spacer fabric has an initial thickness of from about 2 mm to about 25 mm.
13. The method of any one of claims 1 or 7 wherein said spacer fabric outer fibrous layers are at least in part composed of polyester, polyolefin, glass or carbon fibers, or mixtures thereof.
14. The method of any one of claims 1 or 7 wherein the said resilient spacer fibers are at least in part composed of polyester, polyolefin, or glass fibers, or mixtures thereof.
15. The method of claims 2 or 3 wherein said additional fibrous layers are composed of polyester, polyolefin, glass or carbon fibers, or mixtures thereof.
16. The method of claims 8 or 9 wherein said additional fibrous layers are composed of polyester, polyolefin, glass or carbon fibers, or mixtures thereof.
17. A vacuum-infused product as produced by the process of any of claims 1 , 2 , 3 , 4 , 7 , 8 , 9 , 10 or 11 .