Richard H Larsen

US Patent:

41661451, Aug 28, 1979

Filed:

Feb 28, 1977

Appl. No.:

5/772750

Inventors:

Donald M. Hatch - Huntington Beach CA
Richard J. Larsen - Torrance CA

Assignee:

Hitco - Irvine CA

International Classification:

B32B 900
B32B 904
B32B 3120
B32B 3126

US Classification:

428283

Abstract:

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.

US Patent:

44090480, Oct 11, 1983

Filed:

Mar 10, 1975

Appl. No.:

5/556889

Inventors:

Donald M. Hatch - Huntington Beach CA
Richard J. Larsen - Torrance CA

Assignee:

Hitco - Newport Beach CA

International Classification:

B32B 3100

US Classification:

156155

Abstract:

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.

US Patent:

39450937, Mar 23, 1976

Filed:

Jun 10, 1974

Appl. No.:

5/477599

Inventors:

Richard J. Larsen - Torrance CA
Robert W. Mitchell - Hawthorne CA

Assignee:

Hitco - Irvine CA

International Classification:

D06C 300

US Classification:

26 68

Abstract:

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.