Parallel Distributed Processing Volume 1: Foundations

1,227,914. A die for laminated films. NORTHERN PETROCHEMICAL CO. 25 April, 1969 [26 April, 1968], No. 21298/69. Heading B5B. [Also in Division F2] A die for the extrusion of laminated plastic tubing is shown in Fig. 1. Material for the inner ply is supplied through tube 18, the conduit 19 the axial tube 20 and the four radial tubes 21 to the annular chamber 22 and material for the outer ply is supplied through the tube 28 and the feed hole 31 to the chamber 30. From chambers 22 and 30 the inner and outer ply materials are delivered to the annular conical chamber 43, in a molten state and flow under conditions of laminar flow to the die mouth 44. A molten laminate is produced in chamber 43 by virtue of the ring 42. Air from the supply 35 is delivered to the interior of the tube so formed via the hydraulic coupling 33, the tube 32, the hydraulic coupling 34 and the outlet 36 in order to inflate and hence support the extruded tubing. A mandrel 14, the rear end of which threadably engages a nut 15 and the forward end of which threadably engages mandrel head 25, fits slidably in the cylindrical die casing 10. The chambers 22, 30, 43 and the ring 42 are formed by shaping of the mandrel, the die casing and the mandrel head. As can be seen from Fig. 1 the thickness of the film, and the relative thicknesses of the plies can be varied by relative axial movements of the mandrel 14, mandrel head 25 and the die casing 10. Other features of the die include a nut 15 for adjusting the mandrel position, holes 26 in the mandrel head to engage a spanner to facilitate the adjustment of the mandrel head and an adapter head 17. A modification of the above die is shown in Fig. 2 (not shown) having the following features: a sleeve (54) which separates the mandrel from the die casing; the use of 0-rings for producing seals and an adjustment which allows the eccentricity of the die head to be varied.