Core-crush resistant fabric and prepreg for fiber reinforced composite sandwich structures
US6261675A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 23, 1999 |
| Grant date | Jul 17, 2001 |
| Priority date | — |
| Expiry date | Mar 23, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T442/322
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A core crush resistant prepreg for use in making a fiber reinforced composite panel structure is provided. The prepreg comprises a woven fabric consisting essentially of carbon fiber tow strands impregnated with a hardenable polymeric resin composition. Typically the fabric has an areal weight of from about 180 to about 205 grams per square meter. The prepreg has an average fiber tow aspect ratio of less than about 15.4, a prepreg thickness of at least about 0.245 mm, and a prepreg openness of at least about 1.2 percent but less than about 6.0 percent. Preferably, the resin composition is predominantly viscous in nature and has a tan .delta. value of between 0.9 and 2.0 at an elevated temperature between 70.degree. C. and 140.degree. C., and an average epoxy functionality of greater than 2.0. A method for evaluating core crush resistance properties of a prepreg is also provided. The method includes determining a fiber tow average aspect ratio of the prepreg, determining a prepreg thickness, and comparing said average fiber tow aspect ratio and prepreg thickness to a set of predetermined values.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.