IMPROVEMENTS IN OR RELATING TO METHODS AND APPARATUS FOR THE CONTINUOUS FORMATION OF AN EXTRUDED PRODUCT

PCT No. PCT/GB93/01122 Sec. 371 Date Dec. 2, 1994 Sec. 102(e) Date Dec. 2, 1994 PCT Filed May 28, 1993 PCT Pub. No. WO93/25372 PCT Pub. Date Dec. 23, 1993.A method and apparatus for continuously extruding a product, and forming it into a bend by applying a force to it at a point of application downstream of where its surface becomes solid. The force has a transverse component relative to the die axis, and performs work upon the extruded material, extra to the work that has already been performed to extrude it. Non-contact members of applying the force are described, and various ram-type contacting members are illustrated. Alternative means of operation are described in which the point of application of the force to the extrudate during bending varies relative both to the extrudate and to the die, relative to the extrudate only, and relative to the die only. Means to alter the direction of bending are described, and to diminish the necessary bending force by creating a fluctuating melt pressure within the die.