Prepregs sheets

Fig. 8-67 Automated-integrated RP vacuum lay-up process that use prepreg sheets that are in the B-stage.

APC-2 is a semi-crystalline thermoplastic prepreg. The surface roughness characterization for two different batches of APC-2 prepreg are reported in Table 7.2. Batch I is a 152.4 mm (6in.)-wide prepreg sheet, whereas batch II is 304.8-mm wide. In addition, the... 

Figure 5.1 7 Automated-integrated RP vacuum hand lay-up process that usesTS polyester prepreg sheets...

To generate a quality composite, it is important for the resin from the prepreg sheets to mix and to flow into the copper interface. 

The polymer chosen in the UK for preliminary investigations was the PES, due to its ease of manufacture, its low out-gassing in space and light weight, Hollaway and Thome (1987). Prepreg sheets of the polyethersul-phone/carbon fibre (PES/CF) composite were moulded by the technique of film-stacking technology. 

The prepreg (preimpregnated materials) is then delivered to the lamination press. Here the required number of prepreg sheets is stacked between polished steel plates. The plates are further stacked together to form a pack that is then placed into the laminating press s platens. Each pack can consist of 10 laminations, and the press may have 24 platens, making a press load of up to 240 laminations per cycle. The press is closed, and the laminates are consolidated and polymerized (cured) at temperatures from 121 to 204°C, pressures from 200 to 3000 psi, and times from 3 to 120 min. Molded laminates are then trimmed to final size. Some laminates must be postcured by additional heating in ovens. 

Prepreg sheets preformed into a plate in the factory, elevated temperature cured, delivered to site and bonded onto the structure with an ambient cured adhesive. 

FIGURE 8.112 Basic manufacturing steps for MCM-Ls, using fiberglass/resin prepreg sheets as abasis. 

Lower raw material cost Loose sheet copper foil and prepreg sheets are more economical than clad laminate. 

Epoxy content was analyzed on white and black prepreg sheets using the EDAIT-l probe. Eaeh sheet was scanned at two orientations and averaged. Wavelengths chosen were 1254, 1268, and 2164 nm. The range of epoxy resin was 30 to 33% with an SEE of 0.2 and an of 0.991. Two distinct calibrations were required. 

When the textile fabric reinforcement is combined with the matrix to form the composite prepregs, a set of deformation modes are introduced, which may be referred to as top-level deformation modes since they involve the movements of the reinforcement (macro- and micro-level fabric deformation mechanisms) and the matrix. They are in fact the conformation modes of the composite prepreg sheet or group of sheets, as is usually the case, during the forming process. The hierarchy of the top-level deformation modes consist of transverse flow, resin percolation, interply shear and intraply shear, as summarized by Cogswell and revisited by Martin et... 

LCP/carbon-fibre composites have been developed and are used as secondary composites within the aerospace industry. LCP matrices offer low viscosity for the impregnation of the fibres, and excellent chemical resistance. Impregnation is achieved in a cross-head die, after which the composite panels are prepared by compression moulding the stacked prepreg sheets. 

Mitsubishi Chemical Co, 1999. Carbon Fiber Prepreg Sheet (Replark ). Available from http // www.m-kagaku.co.jp/engjish/aboutmcc/division/prod/carbonfiber/r-products.htm. 

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