PROCESS AND EQUIPMENT FOR MAKING COMPOSITE TUBES

摘要

A process and equipment for making seamless composite tubes. Composite material is applied on a mandrel which includes an inflatable bladder and inserted in a single piece mold. The bladder is pressurized for pressing the composite material against the mold wall for molding and curing thereof. In order to prevent seizing of the tube by the mold and thus allow easy removal of the cured tube, the mold is composed of a composite of resin impregnated carbon fiber material wherein the carbon fiber material has a negative coefficient of thermal expansion along the length thereof and is oriented at an angle of between about 15 and 40 degrees relative to a radial plane of the mold. In order to eliminate the use of inefficient and inconvenient cure ovens, an heat generating element is disposed internally of the mandrel for curing of the composite material.