Techniques for coating pipes

A method of coating a joint of a pipe during fabrication of the pipe from pipe sections, comprising:

• positioning a mould tool around the joint to define a mould cavity around the pipe, the mould tool having first and second gates spaced apart from each other;
• injecting molten thermoplastics material through the first gate into a first portion of the mould cavity to advance a melt front in the mould cavity toward the second gate;
• subsequently injecting molten thermoplastics material through the second gate into a second portion of the mould cavity neighbouring the first portion;
• accelerating cooling of the injected material in the first portion of the mould cavity relative to cooling of the injected material in the second portion of the mould cavity;
• and
• removing the mould tool from the joint after the injected material in the mould cavity has cooled to a self-supporting extent.

Apparatus for coating a joint of a pipe during fabrication of the pipe from pipe sections, the apparatus comprising:

• a mould tool that may be positioned around the joint to define a mould cavity and that has first and second gates through which molten thermoplastics material may be injected into the mould cavity, those gates being spaced apart from each other;
• a means for providing molten thermoplastics material;
• a means for injecting molten thermoplastics material into the mould tool;
• and
• a control unit arranged to control a coating process involving the mould tool;
• and the apparatus being arranged to inject molten thermoplastics material through the first gate into a first portion of the mould cavity to advance a melt front in the mould cavity toward the second gate, and subsequently to inject molten thermoplastics material through the second gate into a second portion of the mould cavity neighboring the first portion;
• and to accelerate cooling of the injected material in the first portion of the mould cavity relative to cooling of the injected material in the second portion of the mould cavity.