Press moulding prepreg

Quality-control tests and important process variables 

Typical systems include polyester/glass-fibre sheeting. 

Hou (1986) presented a resin-flow model for long-fibre-reinforced-composite prepreg lamination processing. The model includes the following chemorheological model  

Overall the model combines mass and force balances incorporating the chemorheological model (above), considerations for viscous flow and flow through flbre bundles, to simulate loss of resin during prepreging, the fibre volume fraction, the pressure distribution, temperature effects and part dimensions. Verification experiments show that the model predicts experimental results to within 8%. 

---

A 177 C curing low micro-cracking/low moisture absorbing cyanate resin with a -128 to +121 C service temperature range (without post cure), formulated for press and autoclave moulding. Prepregs in all available fibres and fabrics can be manufactured via hot-melt or solution techniques, a. 1.19 j. 0.96 /o Tg (no post cure) 206"C (with post cure) 258 C... 

A 177 C cure toughened epoxy with a 126-138 C dry and 104 C, wet service temperature. Available in a broad range of tape, fabric and roving prepregs for the manufacture by press moulding or autoclave of... 

For very large parts that cannot be accommodated in ordinary presses, the autoclave process can be used in conjunction with a vacuum bag [3]. In one example, prepreg is encased in a flexible plastic bag, which is situated in an autoclave (Fig. 2.2). A vacuum is applied to draw the bag against the mould surface and heat is applied. The process can be used to produce very large articles, but it can also be scaled down and has advantages for short... 

---