APC-2, laminates

Surface treatment of the composite can have a significant effect on adhesion. Surface treatment enhances one or more of the mechanisms described previously. Wu et al. [15] studied the effects of surface treatment on adhesive bonding for AS-4/APC-2 laminates. They found that the greatest bond strength was achieved from acid etching and plasma etching the composite surface. Table 1 summarizes the various surface treatments that were evaluated. 

Effects of various surface treatments on AS-4/APC-2 laminate for adhesive bonding [15]... 

Figure 7.13 Typical scanning acoustic microscopic image obtained from a [0/90.0]r APC-2 laminate processed at 370°C with 276 kPa for 50 s...

Very few studies have appeared in the literature that specifically address the intimate contact of an angle ply [+0/—0] interface. In a study reported by Li and Loos [22], APC-2 laminates,... 

The Li-Loos intimate contact model was verified for compression molded unidirectional graphite-polysulfone and graphite-PEEK (APC-2) laminae and graphite-PEEK (APC-2) cross-ply laminates. The degrees of intimate contact of the unidirectional and cross-ply specimens were measured by optical microscopy and scanning acoustic microscopy, respectively. The predicted degrees of intimate contact agreed well with the measured values for both the unidirectional and cross-ply specimens processed at different temperature and pressures. 

The intimate contact data shown in Figure 7.16 were obtained from three-ply, APC-2, [0°/90o/0o]7- cross-ply laminates that were compression molded in a 76.2 mm (3 in.) square steel mold. The degree of intimate contact of the ply interfaces was measured using scanning acoustic microscopy and image analysis software (Section 7.4). The surface characterization parameters for APC-2 Batch II prepreg in Table 7.2 and the zero-shear-rate viscosity for PEEK resin were input into the intimate contact model for the cross-ply interface. Additional details of the experimental procedures and the viscosity data for PEEK resin are given in Reference 22. 

An advanced reinforcements system identifies QBT. It is the name for a biaxial thermoplastic (PA, PBT, PET, PP/PPS, PEI, APC-2, Radel), carbon, aramid, and glass pre-impregnated tape. It is unidirectional, interlaced in biaxial form, in continuous lengths and very large width (up to 10 ft). It maintains and improved properties of unidirectional cross-ply laminates, giving the benefit of unidirectional tape in larger and more easily processed formats. It is claimed to be first real alternative to a woven composites compromise, with good drape. 

Keywords squeeze flow, Plytron , full-slip condition, full-stick condition, unidirectional continuous-fiber reinforced composites, shear thinning fluid, Carreau fluid, APC-2, composite laminate, UD laminate. 

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