Method and apparatus for molding structural foam articles

An apparatus for molding flowable plastic material, comprising:

• a source of said flowable plastic material;
• mold means defining a cavity within which said plastic material is received;
• means for cyclically driving a quantity of said plastic material received from said source into said mold means;
• and
• mixing means operatively positioned between said driving means and said mold means through which said plastic material flows as it is driven into said mold means, said mixing means including movable blade means operatively positioned in the flow path of said plastic material so that cyclically driven movement of said plastic material by said driving means causes said plastic material to act against and drive said blade means to move said movable blade means to effect mixing of at least a portion of said plastic material as it flows through said mixing means.

An apparatus for cyclically molding flowable plastic material, comprising:

• a source of said flowable plastic material;
• mold means defining a cavity within which said plastic material is received;
• accumulator maans for cyclically receiving a quantity of said material from said source and for cyclically driving the material received into said mold means;
• and
• mixing means operatively positioned between said accumulator means and said mold means through which said plastic material flows as the material is driven by said accumulator means into said mold means, said mixing means including movable blade means disposed for rotation in the flow path of said plastic material through said mixing means so that cyclic driven flow of said plastic material through said mixing means acts against and drives said movable blade means for rotation thereof to mix at least a portion of said plastic material.