Thermoset plastic pellets and method and apparatus for making such pellets

A method of making filled thermoset plastic pellets comprising:

• mixing thermoset resin and micropheres to form a homgeneous mixture;
• extruding said mixture to form at least one continuous strand;
• depositing said strand on an endless belt conveyor moving at a speed substantially equal to the rate said strand is extruded;
• gelling said moving strand on said moving conveyor by exposing said strand to heating means positioned adjacent said moving conveyor to form a solid strand having a percent tensile elongation of more than 10% which is less than B-staged;
• and
• forming said strand into further curable pellets of thermoset resin filled with microspheres by chopping said gelled strand with chopping means to form said further curable pellets.

A method of making filled thermoset plastic pellets comprising:

• mixing thermoset resin and microspheres to form a homogeneous mixture;
• extruding said mixture to form at least one continuous strand;
• depositing said strand on an endless belt conveyor moving at a speed substantially equal to the rate said strand is extruded;
• curing said moving strand on said moving conveyor by subjecting said strand to ultraviolet radiation to form a solid strand having a percent tensile elongation of more than 10% which is less than B-staged;
• and
• forming said strand into further curable pellets of thermoset resin filled with microspheres by chopping said gelled strand with chopping means to form said further curable pellets.

A method of making filled thermoset plastic pellets comprising:

• mixing thermoset resin and microspheres to form to homgeneous mixture;
• extruding said mixture to form at least one continuous strand;
• depositing said strand on an endless belt conveyor moving at a speed substantially equal to the rate said strand is extruded;
• curing said moving strand on said moving conveyor by subjecting said strand to microwave radiation to form a solid strand having a percent tensile elongation of more than 10% which is less than B-staged;
• and
• forming said strand into further curable pellets of thermoset resin filled with microspheres by chopping said gelled strand with chopping means to form said further curable pellets.

A method of making filled thermoset plastic pellets comprising:

• mixing thermoset resin and microspheres to form to homogeneous mixture;
• extruding said mixture to form at least one continuous strand;
• depositing said strand on an endless belt conveyor moving at a speed substantially equal to the rate said strand is extruded;
• curing said moving strand on said moving conveyor by subjecting said strand to radio wave radiation to form a solid strand having a percent tensile elongation of more than 10% which is less than B-staged;
• and
• forming said strand into further curable pellets of thermoset resin filled with microspheres by chopping said gelled strand with chopping means to form said further curable pellets.

An apparatus for making uncured microsphere-filled thermoset pellets comprising:

• a container defining an interior opening for receiving liquid thermoset plastic resin and microspheres;
• means operatively connected to said container for mixing said resin and said microspheres at a low speed to form a homogeneous mixture;
• means operatively connected to said container for compressing said mixture;
• an extrusion die in fluid communication with said container, said die having a plurality of openings for forming continuous stands of said mixture;
• a conveyor having an endless belt disposed below said die;
• said plurality of openings comprising linear bores extending at an oblique angle relative to a top surface of said belt;
• said belt being rotated below said die wherein said top surface passes said plurality of openings at substantially the same rate of speed as said mixture issues from said die whereby belt receives said mixture thereon without substantially pulling or compressing said mixture;
• a radiation source being disposed adjacent said conveyor and directing radiation at the mixture on the endless belt to gel the strands of the mixture at an accelerated rate into a solid form within from about 10 seconds to 180 seconds from the time at which said strands are extruded onto said belt;
• means contiguous with said conveyor for unloading said strands and dividing said strands into pellets of uncured thermoset plastic pellets filled with microspheres.