Abstract: A method of repairing or reinforcing worn-out underground buried drainpipes by a resin transfer molding process using both flexible tubes and bagging films is disclosed. In the method of this invention, a reinforcement is primarily inserted into a desired position within a target worn-out drainpipe buried underground. The reinforcement consists of a fiber preform internally having a flexible tube, such as a silicon tube, axially extending along the central axis of the preform and wrapped with an adhesive-coated flexible film as a bagging film to provide protection from sewage or underground water. The flexible tube is, thereafter, expanded to bring the fiber preform into close contact with the interior surface of the target drainpipe. The opposite ends of the reinforcement are sealed with two lids. Thereafter, thermosetting resin is transferred into the fiber preform, thus allowing the fiber preform to be impregnated with the thermosetting resin.

Abstract: A hybrid shaft adapted to be used as a drive shaft of an automobile transmission system comprises a unitary cylindrical hybrid stem formed from a metal tube and a composite material layer adhered to the metal tube. The metal tube provides torque-transmission strength to the hybrid shaft while the composite material layer increases a specific modulus of the hybrid shaft. The hybrid shaft is produced by stacking a composite material layer on a metal tube, putting a thermal shrinkage tube on the composite material layer, and co-curing the metal tube and the composite material layer while exerting a longitudinal compression force on the metal tube to prevent it from being thermally expanded.

Abstract: The present invention provides a method for fabricating spindle and roller empying rotation axes made of a composite material, which comprises a step of inserting a front metal part and an end metal part into a front and an end of a rotation axis made of a composite material. In accordance with the present invention, spindle and roller with easy control of balancing and less inertia on rotation, can be fabricated, by employing rotation axes made of a composite material which has a high stiffness, superior torque transfer capability and natural frequency.