CONTROL OF INNER AND OUTER DIAMETERS OF THERMOPLASTIC RESIN TUBULAR FOAM

摘要

PURPOSE:To obtain tubular foam bodies with various outer diameter without changing dies by a method wherein a tubular foam obtained by being taken off at the takeoff speed giving the minimum to the inner diameter or smaller is taken off at a speed exceeding the takeoff speed giving the minimum to the inner diameter. CONSTITUTION:The outer diameter of a tubular foam reduces with the increass of takeoff speed as shown by straight line 1 and the inner diameter shows the minimum at takeoff speed Vb as shown by curved line 2. When takeoff is conducted at takeoff speed V1 smaller than the takeoff speed V0, if takeoff is conducted at takeoff speed V2 greater than the takeoff speed V0 with the same die as a die giving a tubular foam with outer diameter L1 and inner diameter l1, a tubular form with outer diameter L2(