Complex vacuum external calibration system for plastic extrusions, avoiding costly and inconvenient block construction methods

摘要

The block comprises tightly stacked plates connected together. Passages through the plates combine to form the calibration channel (6). Further passages form cooling channels. Vacuum channels are formed by a third set of passages. These different passages in the block, are so formed that they remain separate. Preferred Features: Second and third sets of openings are vertical or transverse with respect to the longitudinal axis. Some of the plates have auxiliary channels in fourth sets of recesses, introducing sealing water into the main channel (6). Third and/or fourth recesses discharge into the first recesses forming the calibration channel. The plates are transverse with respect to the latter. The foregoing principles are further elaborated, salient features being use of plates of differing type. They are all metal or are of different materials. Hard plates may alternate, comprising e.g. wear-resistant steel. Plates of a third type may act as separators between the others. Close-fitting location bolts align the plates.