Introduction:

PVC Casting film is produced by casting forming system with evenly compounded PVC polymer resin, plasticizer, stabilizer and etc. additives, and it is wildly applied in Various  packing material areas. Normal forming equipment for this PVC casting film is conical twin screw extruder or single screw extruder, yet each of the above extruders has its limitation:

1. Conical twin screw extruder can provide certain compounding effect and can produce the film by direct extrusion. However, its compounding ability is weak, cannot produce high quality casting film and usually be used for low level product. For improving the final product quality, better formulation with higher cost can be applied but the final profit is reduced.

2. Sigle screw does not possess compounding effect for PVC polymer resin and the additives, so it can only be used with compounded PVC polymer pellet and form the film by melting extrusion. PVC is a thermosensitive materials, multiple times melting will increase its decomposition, thusly lowering the casting film product performance. This single extruder method can only be applied for high plasticizer content non-transparent film product, less scope of application

Characteristics of the PVC casting film produced by CENMEN:

Regarding the compounding effect is the key for producing high quality PVC casting film, CENMEN using two stages extrusion technic to complete the compounding process for PVC polymer resin and additives. This method is capable of applying Various  PVC film formulation, and the final film product has a wide range of applications.

1. Up stage twin screw extruder for heating the raw material to melt, and through the interaction of screw, the components are dispersed sufficiently and evenly, and finally a melt with good plasticization is formed. Fine compounding effect of the twin screw extruder improves the physical properties of the final casting film product, the exhaust vacuum system is also equipped with the extruder for effectively removing water vapor and volatile matter.

2. Lower stage single screw extruder mainly provides transition and compress effect for the compounded melt from the up stage, then the melt will be extrusion casting formed to film by the forming system. Cooling water through the screw core shaft and the barrel provide temperature control for the melt, preventing high temperature causing material decomposition, effectively increasing the performance and appearance for the final film product.