Parison separation assembly

摘要

A separate parison separation assembly for each parison in a multiple parison blow molding apparatus. Each assembly has a shear plate secured in a recess machined into the mold in order to provide a positive and repeatable location of the shear plate. The shear plate is square and provides eight cutting edges; each of the four sides of the shear plate by rotating the shear plate as an edge wears, and by turning it over. The shear plate has a useful life up to eight times that of the prior art designs. The cut-off knife for each assembly is secured to the other half of the mold, directly on its surface, with a compression pocket cut into the face of this half of the mold to contain and to compress the parison between the mold halves. The design eliminates open space at the edge where the flash forms, reducing the mass of polymer at the edge and thus the temperature of the flash edge.