Rotomolding and Rotolining Processing Conditions

This section provides examples of temperature and time cycles for rotomolding select fluoroplastics. The most frequently molded fluoroplastics, by this technology, are PFA, FEP, PVDF, ETFE, and ECTFE. Rotation ratios for these resins follow the general guidelines that have been listed in Table 6.31. In summary, the rotation ratio ranges from 1 5 for cylinders to 8 1 for oblongs. A typical rotation ratio for a medium part is 4 1. The exact value of rotation ratio for each resin must be determined experimentally. 

The mold was charged with a free-flowing PFA powder comprised of two separate distributions. The fine cut powder had a particle size of500 pm or lower. The coarsely divided PFA powder, which formed the chips, had a size range of 3.2-6.2 mm. After 

Shapes Rotation Ratio Rotation Speed of Major Axis 

Horizontally mounted oblong articles and straight tubes 8 1 8 

Rectangular shapes with more than two or thin sides when run at a ratio of 4 1 2 1 8 

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