The Design Optimisation of the Co-extrusion of a Wood-like Grain Surface Composite Polymer Profile

A wood-like grain surface composite polymer profile (or wood-like profile) was fabricated by the extrusion moulding of melting multi-component polymers through a co-extrusion die, with two extruders feeding the co-extrusion die simultaneously. To improve the extrusion velocity uniformity of melting composite polymers, and decrease the distortion of wood-like grain profiles, this study treats the velocity equality among sub-regions in the wood-like profile cross-sections at the exit of the co-extrusion die as its optimisation objective. Meanwhile, the compression section gap, which exerts a significant influence on flow uniformity is selected as the design variable. Finite element numerical simulation and an ERP system are adopted to optimise the design in combination with a CAD/CAE network system co-extrusion die expert database of concurrent engineering. The optimisation design of case studies confirms that the velocity uniformity of the optimised wood-like grain profile melts presents a significant improvement in each sub-region at the exit of the co-extrusion die. Moreover, the distortion of composite profiles is decreased. The structural dimensions and performance of the composite profiles meet industrial demands.