Thermoforming hot-compacted semifinished plate products

In regard to molding self-reinforced thermoplastic composites, two different methods can be differentiated. For one, there is thermoforming for previously hot-compacted, plain semifinished plate products. Second, there is compression molding, which is used for layered semifinished textile products or high precision construction parts. 

Thermo forming hot-compacted semifinished plate products 

FVom a process-technological point of view, thermoforming previously hot-compacted semifinished PP-plate products proves to be the simpler option. The semifinished plate pro- 

Depending upon the machinery, preheating is either carried out using an infrared radiator or a convection oven [34,55,66]. As in the case of hot-compaction, a shrinking of the self-reinforced material should be prevented by prestressing the semifinished product on a tenter or blank holder [55]. 

A clear, processing-technological differentiation to the previous hot-compaction can be made and is based upon the tempering of the shaping tool, which possesses a temperature that is far below the hot-compaction temperature or that is at room temperature. The preheated, self-reinforced semifinished plate products are inserted into a cold cavity and formed under pressure. This procedure allows relatively short cycles at low molding ratios. 

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