Apparatus and method for pultruding reinforced plastic articles

Claim 1

An apparatus for pultruding reinforced plastic parts, said apparatus comprising: supply means for supplying a plastic resin-impregnated reinforcing material; first forming means for partially consolidating said material and for shaping the partially consolidated material to an oversized form, said first forming means being heated and comprising a tapered portion which is tapered from an entry side thereof to a constant cross-section portion, said constant cross-section portion opening at an exit side of said first forming means, wherein an intersection of said tapered and constant cross-section portions is nearer said exit side than said entry side of said first forming means for minimizing frictional buildup between said material and said first forming means; second forming means, spaced from said first forming means, for finally consolidating said material and for shaping the finally consolidated material to a final form, said second forming means being cooler than said first forming means and comprising a tapered portion which is tapered from an entry side thereof to a constant cross-section portion, said constant cross-section portion opening at an exit side of said second forming means, said tapered portion of said second forming means being shorter than said tapered portion of said first forming means for providing fast consolidation of said material without cooling said material too quickly before said material enters said constant cross-section portion of said second forming means; and pulling means for pulling said material from said supply means and through said first and second forming means.

Claim 2

An apparatus for pultruding reinforced plastic parts, said apparatus comprising: supply means for supplying a plastic resin-impregnated reinforcing material; first forming means for partially consolidating said material and for shaping the partially consolidated material to an oversized form, said first forming means being heated and comprising a tapered portion which is tapered from an entry side thereof to a constant cross-section portion, said constant cross-section portion opening at an exit side of said first forming means, wherein an intersection of said tapered and constant cross-section portions is nearer said exit side than said entry side of said first forming means for minimizing frictional buildup between said material and said first forming means; second forming means, spaced from said first forming means, for finally consolidating said material and for shaping the finally consolidated material to a final form, said second forming means being cooler than said first forming means and comprising a tapered portion which is tapered from an entry side thereof to a constant cross-section portion, said constant cross-section portion opening at an exit side of said second forming means, said tapered portion of said second forming means being shorter than said tapered portion of said first forming means for providing fast consolidation of said material without cooling said material too quickly before said material enters said constant cross-section portion of said second forming means; and pulling means for pulling said material from said supply means and through said first and second forming means.

Claim 9

A method of pultruding plastic articles comprising the steps of: making a reinforced plastic material by resinimpregnating a fiber string; partially consolidating said reinforced plastic material by passing said reinforced plastic material through a heated first die such that said material is rough formed and shaped oversize with respect to a final, desired form, said step of partially consolidating comprising: passing said material through a tapered first portion of said first die; and passing said material through a constant cross-section portion of said first die which is relatively shorter than said tapered portion thereof; whereby friction is minimized in said first die; and finally consolidating said material by passing said material through a second die such that said material is shaped to said final, desired shape, said second die being cooler than said first die, said step of finally consolidating comprising: passing said material through a tapered portion of said second die which is relatively shorter than said tapered portion of said first die, thereby quickly consolidating said material and preventing premature cooling thereof; and passing said material through a constant cross-section portion of said second die which is relatively longer than said tapered portion of said second die.

Claim 10

A method of pultruding plastic articles comprising the steps of: making a reinforced plastic material by resinimpregnating a fiber string; partially consolidating said reinforced plastic material by passing said reinforced plastic material through a heated first die such that said material is rough formed and shaped oversize with respect to a final, desired form, said step of partially consolidating comprising: passing said material through a tapered first portion of said first die; and passing said material through a constant cross-section portion of said first die which is relatively shorter than said tapered portion thereof; whereby friction is minimized in said first die; and finally consolidating said material by passing said material through a second die such that said material is shaped to said final, desired shape, said second die being cooler than said first die, said step of finally consolidating comprising: passing said material through a tapered portion of said second die which is relatively shorter than said tapered portion of said first die, thereby quickly consolidating said material and preventing premature cooling thereof; and passing said material through a constant cross-section portion of said second die which is relatively longer than said tapered portion of said second die.

Claim 14

A method of continuously forming reinforced plastic articles comprising the steps of: pulling a fiber strand from a fiber supply means; impregnating said strand wth a plastic resin to form an impregnated strand of reinforced plastic material; rough forming said material into a rough shape oversized with respect to a final shape by passing said material through heated first forming means having a tapered portion, sized for minimizing friction which can cause ball-ups in said material, followed by a constant cross-section portion which is shorter than said tapered portion; and final forming said rough shape into said final shape by passing said material through second forming means having a tapered portion shorter than said tapered portion of said first forming means for providing fast consolidation of said material while preventing premature cooling thereof.

Claim 15

A method of continuously forming reinforced plastic articles comprising the steps of: pulling a fiber strand from a fiber supply means; impregnating said strand wth a plastic resin to form an impregnated strand of reinforced plastic material; rough forming said material into a rough shape oversized with respect to a final shape by passing said material through heated first forming means having a tapered portion, sized for minimizing friction which can cause ball-ups in said material, followed by a constant cross-section portion which is shorter than said tapered portion; and final forming said rough shape into said final shape by passing said material through second forming means having a tapered portion shorter than said tapered portion of said first forming means for providing fast consolidation of said material while preventing premature cooling thereof.