Polymer fiber composite with mechanical properties enhanced by particle size distribution

A composite composition, capable of extrusion into a dimensionally stable structural member, which composition comprises:

• (a) about 40 to 70 wt-% of a polymer comprising vinyl chloride;
• (b) about 30 to 50 wt-% of a mixed fiber, the mixed fiber comprising a first fiber collection comprising a cotton fiber, a glass fiber, a synthetic polymer fiber, or mixtures thereof, having a thickness of less than about 0.5 mm and a minimum aspect ratio of about 50 and a second fiber collection comprising wood fiber having a maximum dimension of less than about 10 mm and an aspect ratio of about 1.8 to about 10;
• wherein the mixed fiber is dispersed throughout a continuous polymer phase;
• and
• (c) less than about 10 wt-% water;
• wherein the mixed fiber is dispersed throughout a continuous polymer phase.

A composite pellet, capable of formation into a structural member, which pellet comprises a cylindrical extrudate having a radius of about 1 to 5 mm, a length of about 1 to 10 mm, the pellet composition comprising:

• (a) a continuous phase of a thermoplastic polymer;
• and
• (b) about 5 to 60 wt-% of a mixed fiber comprising a blend of a collection of a first fiber having an aspect ratio of greater than about 20 with a collection of a second fiber having an aspect ratio of about 1.8 to 10 wherein said second collection is present in an amount greater than that produced through breakage of said first collection in the extrusion processing of the composite pellet;
• wherein the mixed fiber collections are dispersed throughout a continuous polymer phase.