NOVELTY - A pipe molding apparatus has a mold tunnel including upstream mold block (3) and downstream mold block(s) (7). Each mold block has a hollow pipe forming region (14, 30) which is decreased in both diameter and length relative to the hollow pipe forming region of the upstream mold block.
USE - For molding plastic pipes.
ADVANTAGE - The invention compensates for the shrinking of the pipe such that even with the downsizing, the same pipe profile is found in each of the mold blocks.
DETAILED DESCRIPTION - A pipe molding apparatus has a mold tunnel including upstream mold block and downstream mold block(s). Each mold block has sections which close to form the pipe and open to release the pipe. The mold blocks move together downstream of the apparatus when forming the pipe. The pipe cools and shrinks in both diameter and length when moving through the mold tunnel. The mold blocks move separately upstream of the apparatus when releasing the pipe. Each mold block has a hollow pipe forming region which is decreased in both diameter and length relative to the hollow pipe forming region of the upstream mold block.
DESCRIPTION OF DRAWING(S) - The figure shows the interior hollow regions of the mold blocks.
Upstream mold block (3)
Intermediate mold block (5)
Downstream mold block (7)
Hollow pipe forming regions (14, 22, 30)
