Compression molding typical presses

By analogy with compression molding, thermosetting resins plus fibrous reinforcement can be pressed between matching mold halves, with heat and moderate pressure, and cured directly into finished products. Typical cure cycle is about a minute. Half of all reinforced thermoset products are made in this way. Major applications are in the automotive, electrical/electronics, appliance, and business machine industries. 

Figure 4 Typical Iso-lntenslty Contour Patterns oC Compression Molded 40/60 PET/POB Copolyester A) 255 c, Press Cooled B) 285 C, Ice Water Quenched.

Some polyurethane materials (e.g., flexible foams with a small degree of crosslinking or monolithic thermoplastic polyurethanes) can be processed by methods typical of thermoplastic polymers. Compression molding in a hydraulic press is most often used to this purpose. At high temperature and pressure, the crosslinks are broken and the material flows in the mold. In this way,... 

Figure 18 A typical compression press molding line.

Molding is the process where a pattern is pressed or embedded into special sand to the desired shape or form. Alternatively, the pattern can be placed on a molding board, and the sand rammed or compressed around the pattern. Figure 4.4 shows the typical molding flow. The sand and binder are first... 

In a typical molding procedure the molding powd is heated in a steam oven at 112° for 2—4 hrs, then pressed to shape at 120° using 30000psi with 5mins dwell time under a vac of at least 4mm. A billet of PBX is thus produced with a compressive strength of at least lOOOOpsi (Refs... 

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