Thermosetting plastics , adhesives polyurethane

SCRIMP process This Seeman Composites Resin Infusion Process (SCRIMP) is described as a gas-assist resin transfer molding process. As an example glass fiber fabrics/ thermoset vinyl ester polyester plastic and polyurethane foam panels (for insulation) are placed in a segmented tool. A vacuum is pulled with a bag so that a huge amount of plastic can be drawn into the mold (Marco process approach). Its curved roof is made separately and bonded to the box with mechanical and adhesive fastening. It is similar to various reinforced plastics molding processes. 

Thermosetting plastics (e.g., epoxies diaUyl phthalate polyesters melamine, phenol and urea formaldehyde and polyurethanes) are joined either mechanically or by adhesives. Their thermosetting nature prohibits the use of solvent or thermal welding processes however, they are easily bonded with many adhesives. 

Thermoset plastics are undamaged by the liquid adhesive, and these include Glass fibre polyester composite. Epoxies, Polyurethanes, and Bakelite materials based on phenolic resins. 

Factors most likely to influence adhesive selection are listed in Table 7.13. However, thermosetting adhesives such as epoxies, polyurethanes, or acrylics are commonly used for structural application. The adhesive formulations are generally tough, flexible compounds that can cure at room temperature. The reasons that these adhesives have gained most popularity in bonding of plastics are summarized in this section. 

Polyurethane adhesives currently used to bond most thermosets, including glass fibre reinforced plastics (GRP), sheet moulding compound (SMC), glass fibre reinforced epoxy (GRE), and thermoplastic composites including ABS, PVC, acrylics, polycarbonates, etc., are pre sented in Table 20. 

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