Plunger molding machine with tapered bore and thermal transfer fins

A plunger molding machine for forming a composite polymer from a mixture of base polymer material and reinforcing particles having an aspect ratio greater than 1:1, comprising:

• a barrel assembly having a first end and a second end opposite said first end, said barrel assembly including,
• a barrel bore extending through said barrel assembly, said barrel bore having an inner surface, an input end at said first end, an output end at said second end and a longitudinal axis extending from said first end to said second end, and
• longitudinal fins, each of said fins having a height, a proximal end and a distal end, said fins disposed on said inner surface, said fins protruding into said barrel bore from said inner surface and being substantially aligned with said longitudinal axis, wherein each of said proximal ends is connected to the interior surface, each of said distal ends extending inwardly thereby defining a central unobstructed region in said bore;
• a plunger housing having a plunger bore extending therethrough, defining an initial melt chamber and in communication with said first end of said barrel bore;
• and
• a plunger within with said plunger bore, said plunger being reciprocatable within said plunger bore and into said first end of said barrel bore.