Accession Number:

ADA242396

Title:

Novel Vacuum Bag Processing Approaches to Void Reduction in Carbon/Epoxy Composites

Descriptive Note:

Final rept.

Corporate Author:

ARMY LAB COMMAND WATERTOWN MA MATERIAL TECHNOLOGY LAB

Personal Author(s):

Report Date:

1991-09-01

Pagination or Media Count:

25.0

Abstract:

Vacuum bag and autoclave cure methods for fabricating reproducible quality polymer composites are well established and standardized. As this field of composites processing continues to mature, the thrust of developmental work naturally shifts to areas of need. One current thrust area is an expanding effort to develop more cost effective processing methods that do not sacrifice part quality. Several novel void reduction techniques were investigated in this study. They are vibration-assisted vacuum composite processing VAVCP, porous scrim layering PSL, microporous membrane processing MMP, and Narmco Materials, Inc.s Thick Laminate Prepreg TLP. In VAVCP, low frequency vibration was applied during the pregelation period of the cure cycle of vacuum bag processed carbonepoxy laminates. This process affected only established gas bubbles. Decreased void content in excess of 50 and increased laminate densification of 0.8 were measured.d Data also indicated an approximate 10 increase in size of the remaining voids. The PSL process had no detectable effect on void content. MMP showed the ability to remove volatile water vapor from within the preform interior. Narmcos TLP lowered void content of vacuum bag processed laminates by 50. Volatile gas and mechanically entrapped gas bubbles respond to different methods of removal from the preform interior.

Subject Categories:

  • Laminates and Composite Materials

Distribution Statement:

APPROVED FOR PUBLIC RELEASE