WPC extrusion and co-extrusion: process and cap layers

Shaping the material #

Wood–polymer products can be manufactured by extrusion, co-extrusion, injection moulding and thermal moulding. The route depends on the product geometry and material system. Long profiles and individual moulded parts need different production approaches.

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A cap is a separate layer #

Capped WPC products have a polymer-rich outer layer around some or all of the composite core. Capping is intended to help protect the core and manage surface performance. Coverage, layer integrity and exposed ends still deserve attention.

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Questions for a production review #

Ask how raw materials are checked, how process conditions are recorded and how profile dimensions are verified. Request the acceptance criteria for the cap, surface finish and finished product. Keep retained samples linked to batch records.

Validate the finished profile #

A successful trial run is a starting point. Agree which product tests and manufacturing checks must pass before release. Treat a change to the formulation, cap or geometry as a reason to review whether existing evidence still applies.

Practical comparison checklist

Common questions