Hybrid pultruded products and method for their manufacture
AssigneeWeyerhaeuser Company
InventorFrank C. Beall
Life of this patent
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Abstract
The present invention is a composite pultruded product and the method for its manufacture. The product is made with a plurality of longitudinal glass roving strands. In addition, a cellulosic mat is used in association with the roving. The mat serves as a filler, or reinforcing filler, to ensure uniform resin distribution within the product even when the glass content is significantly reduced. The method can be carried out on convention pultrusion equipment with little or no modification. The cellulose fiber mats may be either air laid or wet laid and should have an ultimate moisture of 3% or less before being incorporated into the pultruded product.
Claims21
A composite pultruded product consisting essentially of a plurality of longitudinally oriented essentially parallel glass roving strands;
- and a parallel oriented cellulosic mat interlayered between the roving strands, both the roving strands said cellulosic mat having a moisture content of 3% or less, and cellulosic mat being completely saturated with and enclosed within a resin matrix, wherein the glass roving strands comprise from 10-45%, the cellulosic mat from 4-40%, and the resin 40-70 % of the product, all measured by volume.
A method of making a composite pultruded product which comprises:
- providing a heated pultrusion die;
- supplying a plurality of essentially parallel continuous glass roving reinforcing strands to the die;
- further supplying in parallel a cellulosic mat to the die, said mat having a density no greater than about 0.45 g/cc and a basis weight in the range of about 100-600 g/m.sup.2 ;
- drying said cellulosic mat to a moisture content of 3% or less;
- impregnating the roving and dried cellulosic mat with a thermosetting resin;
- supporting said cellulosic mat on and enclosing said cellulosic mat within said roving strands;
- and
- drawing the impregnated materials through the heated die to form a pultruded product whereby the cellulosic mat reduces the density of the product while serving to maintain uniform resin distribution throughout the pultruded product.
Dependencies are inferred from the claim text.