Abstract: A coextrusion die for extruding multilayer thermoplastic material in the form of a tube. The die is of the type known as a spiral mandrel die wherein the die mandrels are provided with helical grooves on their peripheries. At least one spiral mandrel has helical grooves of opposite hand than those of the remaining mandrels.

Abstract: A drive for a flying transfer winder wherein a continuously traveling web is transferred from a fully wound roll to a new core. A single winder drive motor is selectively connected to the winding cores and the motor speed is controlled by a dancer roll upstream of the winder. An auxiliary drive is provided to bring up the peripheral speed of the new core at the time of transfer to a speed which is somewhat less than the web speed. Drive means, including overrunning clutches, are provided in the winder drive and auxiliary drive to allow a smooth and controllable movement of the dancer roll during transfer of the web and transfer of control to the winder drive motor.