Process for the continuous manufacture of spacers for coaxial pipe systems.

摘要

A pipe (8) for carrying a gas or liquid is thermally insulated with plastics foam (10) and enclosed in an outer co-axial pipe (9). The inner pipe is held co-axially to the outer pipe (9) by a strip of plastic foam, which is wound in a spiral around the inner pipe. This plastic foam strip is made by forming a strip of rectangular cross-section in a U shaped mould. The strip so formed is then cut almost right through along equally spaced transverse lines to form a chain of blocks (6) joined together at their bases but with a slot (5) between consecutive blocks. Each block (6) may be cut through on a diagonal line or these diagonal cuts may be restricted to alternate blocks. This system of cuts facilitates the winding of the strip around the pipe.