Abstract: Self venting ablative carbon or graphite composite materials are prepared by interspersing low temperature degradable thread within the woven carbon or graphite cloth prior to impregnation with a phenolic or resin matrix. The degradable threads do not degrade during composite curing, but do degrade at a temperature less than the thermal decomposition (char) temperature of the cured composite material. Thus, as the threads decompose, they leave pores throughout the cured composite which are available to vent gaseous decomposition products produced as the resin matrix approaches the char temperature. Venting the resin decomposition products reduces internal pressure within the composite material thereby reducing the likelihood of spalling and ply lifting.

Abstract: A strong, light-weight flexible bearing, particularly suitable for use in mounting a movable thrust nozzle to a rocket case, is made by stacking reinforced plastic shims, having the forms of concentric, spherical zones, alternately with layers of elastomer and bonding them together. A protective heat and flame barrier is formed by providing an especially refractory outer edge on each shim, which extends beyond the layers of elastomer. Each shim is made by:preparing a mold surface that forms a spherical zone of unique radius; filling a refractory cloth with a curable, liquid resin; placing segments of the cloth on the mold surface in an overlapping arrangement until the desired shim thickness is attained; preparing a second mold surface substantially parallel to the first: clamping this over the cloth segments on the first mold surface; and applying heat and pressure to the cloth segments until the resins are cured.