Honeycomb from paper having a high melt point thermoplastic fiber
View Patent ↗This invention relates to a honeycomb including articles such as a panel or aerodynamic structure comprising matrix resin and paper, the paper comprising 50 to 80 parts by weight fibrous material having a modulus of 600 grams per denier (550 grams per dtex) or greater, 0 to 50 parts by weight powdered inorganic material, and 20 parts by weight or greater thermoplastic fiber, the improvement comprising the thermoplastic fiber is a binder for the paper and has a melting temperature above the curing temperature of the matrix resin; a glass transition temperature of greater than 100° C., and the weight average molecular weight of the thermoplastic polymer in the thermoplastic fibers changes 20% or less after being maintained for 10 minutes at the melting temperature.
1. A honeycomb comprising matrix resin and paper, the paper consisting of 50 to 80 parts by weight high modulus fibrous material having a modulus of 600 grams per denier (550 grams per dtex) or greater, 0 to 50 parts by weight powdered inorganic material, and 20 parts by weight or greater thermoplastic fiber, wherein
the thermoplastic fiber is a binder for the paper during the formation and calendering of the paper and has
i) a melting temperature above the curing temperature of the matrix resin,
ii) a glass transition temperature of greater than 100° C.; and
wherein the weight average molecular weight of the thermoplastic polymer in the thermoplastic fibers changes 20% or less after being maintained for 10 minutes at the melting temperature.
2. The honeycomb of claim 1 wherein the thermoplastic fiber is present in an amount of from 20 to 40 parts by weight.
3. The honeycomb of claim 1 wherein the high modulus fibrous material comprises para-aramid fiber.
4. The honeycomb of claim 3 wherein the para-aramid fiber is poly (paraphenylene terephthalamide) fiber.
5. The honeycomb of claim 1 wherein the high modulus fibrous material is selected from the group of polybenzazole fiber, polypyridazole fiber, carbon fiber, and mixtures thereof.
6. The honeycomb of claim 1 wherein the thermoplastic fiber comprises polyethylene naphthalate.
7. The honeycomb of claim 1 wherein the thermoplastic fiber comprises polyamide.
8. The honeycomb of claim 1 wherein the thermoplastic fiber is selected from the group consisting of polyolefin, polyimide, polyetherketone, polyamide-imide, polyether-imide, and mixtures thereof.
9. The honeycomb of claim 1 wherein the powdered inorganic material is mica, vermiculite, silica, or glass.
10. An article comprising the honeycomb of claim 1 .
11. An aerodynamic structure comprising the honeycomb of claim 1 .
12. A panel comprising the honeycomb of claim 1 and a facesheet attached to a face of the honeycomb.