Blown film line schematic

Figure 5.6 Blown film line schematic with more details...

Fig. 3-23. (a) Schematic of a basic (vertical-up) blown film line, (b) Geometry of collapsing bubble. 

Figure B.4 Schematic of blown film line. (Ref Barry, C.M.F., and Orroth, S.A., Processing of Thermoplastics , Modern Plastics Handbook, C.A. Harper, ed., McGraw-Hill, New York, 20(X))...

The spiral die, commonly used to extrude tubular blown films, eliminates weld line effects and produces a thermally and geometrically homogeneous extrudate. The polymer melt in a spiral die flows through several feed ports into independent spiral channels wrapped around the circumference of the mandrel. This type of die is schematically depicted in Fig. 3.18. 

Fig. 3 Schematic of spiral mandrel blown film die operation (1) ring-shaped melt distribution (2) die body (3) spiral flow mandrel (4) sizing ring (5) spreader (6) film bubble (7) frost line (8) solidified film (9) bubble collapsing rollers (10) nip rollers (11) external bubble cooling air (12) internal bubble cooling air inlet (13) internal bubble cooling pipe and (14) heated internal bubble air return.

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