High shear strength pultrusion
AssigneeEbert Composites Corporation
InventorsDavid W. Johnson, W. Brandt Goldsworthy, George Korzeniowski
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Abstract
To produce a pultrusion which can be machined without undue strength loss bidirectional woven fiber fabric is modified to be pultrudable into a high shear strength composite member. In a preferred form of the invention the fabric is pleated in the pultrusion process to create an endless wall of stacked switch-back pleated layers which defines a box beam wall in one example, and the shaft of a bolt in another. Products produced by this process have improved isotonic strength qualities over currently produced pultrusions, which are limited to unidirectional fibers, continuous fiber mats, or alternating layers of non-woven 0.degree. and 90.degree. cloth and do not have the shear strength inherent in the pleated configuration.
Claims5
A method of pultruding composites to define a monlithic pultruded stack of switchback bidirectional woven fiber cloth layers using a pultrusion machine having a resin bath, a die, and means for pulling bidirectional woven fiber cloth through said bath and said die, comprising the following steps:
- (a) with a jig that folds bidirectional woven fiber cloth fed therethrough from a roll of flat bidirectional woven fiber cloth stock into a configuration having consecutive switchback pleats with longitudinally extended fold lines, the step of drawing bidirectional woven fiber cloth from a roll of flat bidirectional woven fiber cloth stock and feeding same through said jig to form same into a pleated ribbon;
- and,
- (b) passing said pleated ribbon through said bath and die to compress same into a monolithic stack comprised of the consecutive switchback pleats of said ribbon bonded together by solidified resin from said resin bath.
Dependencies are inferred from the claim text.