3 Fundamentals of press design

Sheet metal forming lines
larly stringent requirements on the pressing process (Fig. 4.4.40). The
major difference between pressing glass fiber-reinforced plastics and
sheet metal forming lies in the material behavior, the wall thickness of
the produced components and the forming speed.
In sheet metal forming, the thickness of the part depends on the
starting blank. The material thickness of a plastic part, in contrast, is
determined by the parallelism and the cavity of the tool. Furthermore,
plastic is inserted in the press in a malleable condition. It is shaped,
when using the SMC process, by the application of heat and when
using the FRTP process by the dissipation of heat to form a stable com-
Fig. 4.4.40 Hydraulic plastic press for SMC and FRTP parts
nominal press force: 18,000 kN; maximum stroke: 1,300 mm
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