MANUFACTURING METHOD FOR STRUCTURAL MEMBERS FROM FOAMED PLASTIC COMPOSITES CONTAINING WOOD FIBER OR FLOUR

摘要

Structural members for doors and the like can be manufactured from plast ic foamed composites containing wood flour. These structural members are formed by dry mixing a blend of powders including PVC powder, wood flour, powdered thermal stabilizers, powdered foaming agent and a powdered gelatinization agent; adding the mixed powder to a thermal stirring mixer to obtain a homogeneous dispersion of the several powders; transferring the homogeneous dispersion of powders to a col d stirring mixer and stirring at speeds sufficient to avoid agglomeration of the homogeneous dispersion of the several powders; and placing the non-agglomerated homogeneous dispersion of the several powders in a feeding hopper of an extrusion machin e and extruding shapes for the desired components. Vacuum venting of the extrusion machine can be controlled to achieve components with more desirable surface features . Lubricants can be added to the homogeneous dispersions of the several powders to aid in the extrusion process.