Effect of impregnation conditions on prepreg properties and honeycomb core crush

• Published in: Polymer composites Vol. 18; no. 1; pp. 90 - 99
• Main Authors: Martin, C. J., Putnam, J. W., Hayes, B. S., Seferis, J. C., Turner, M. J., Green, G. E.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.02.1997; Willey
• Subjects: Applied sciences; Composites; Exact sciences and technology; Forms of application and semi-finished materials; Polymer industry, paints, wood; Technology of polymers; Impregnation; Fiber reinforced materials; Composite materials; Mechanical properties; Prepreg; Processing parameter; Honeycomb structures
• ISSN: 0272-8397; 1548-0569
• DOI: 10.1002/pc.10264

The effects of fiber tension, line speed, and impregnation temperature and pressure in the prepregging process used to manufacture a commercial high temperature toughened epoxy prepreg were investigated in a Design of Experiments (DOE) to understand core crush in honeycomb composite structures. The prepregs developed in this DOE were characterized by tack, permeation, optical microscopy, and frictional resistance. Of these methods, frictional resistance was found to correlate with core crush. Tack, permeation, and optical microscopy provided a basis for understanding this relationship through impregnation and morphology. Prepregs manufactured with high fiber tension showed greater crush and less frictional resistance than prepregs with manufactured low fiber tension. These low tension prepregs were found to have more fibers at the prepreg surface, allowing them to grip the adjacent surface and resist slippage. By identifying the key factors influencing honeycomb core crush, the prepregging process was modified, producing a crush‐resistant prepreg for end use manufacture.