Hitco, Inc.

Richard J Larsen

Donald M Hatch

Robert W Mitchell

A carbon-organic resin composite which has been initially shaped as by molding and in which the resin binder has been at least partially precured is transformed into an all-carbon composite and substantially densified by a continuous process in which the composite is continuously heated at different temperatures and subjected to increased pressure. Initially, the composite is heated at a first rate to a temperature on the order of 1000.degree. F., the first rate and the increased pressure applied to the composite being selected to substantially decompose the resin rapidly but without delamination or other damage to the composite. Heating is then continued at a second rate until the composite undergoes substantial softening and becomes plastic, typically at a temperature in excess of 3500.degree. F. Thereafter the composite is maintained at a high temperature, typically in excess of 5000.degree. F., for a selected period of time while at the same time continuing the application of high pressure to provide substantial densification of the composite. The continuous process is carried out in 6-12 hours for composites within a given size range.

High temperature consolidation process

High temperature consolidation process for the production of a

The transverse properties of high modulus fabric such as graphite are significantly improved by continuously processing the material through a multiple roller unit under warp tension while restraining fill shrinkage by wrapping the material no less than 180.degree. around each roll and by minimizing unrestrained inter-roll travel by controlling the inter-roll span. Graphite precursor fabrics such as polyacrylonitrile (PAN) can be stretched as high as 45% in the warp direction with as little as 1-2% shrinkage in the fill direction. The invention also relates to simultaneous stretching and preoxidation of the precursor fabric under tension and while minimizing fill shrinkage.

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Torrance, CA, United States of America

Richard J Larsen