Casting film is widely used in different areas, here we list some as below:

　　- Flexible package: CPP cast film line, CPE cast film line.

　　-Sanitary product : PE breathable film, PE emboss film, PE perforate film.

　　-EVA/POE film for encapsulating solar modules, PVDF film for

　　-High barrier film, PVC cling film, PE cling film, PEVA glove film, TPU cast film, PVB/EVA glass film.

　　Different application require different equipment, so each cast film line is customized.

　　Nantong Sanxin Plastics Equipment Technology Co.,Ltd is started to make cast film line since 2000, before then, the machines are mostly imported from Europe or America. We are willing to share the technology with you.

　　The cast film line is consisted of extrusion platform, extruder, screen changer, gear pump, feed block, die, air knife, vacuum chamber, edge pin, cast system, MDO system, corona treater, thickness gauge, defect detector, edge recycling, winder and unloading.

　　Today we share the knowledge of extrusion platform.

　　When talking about the extruder system, mostly we will think about screw and barrel, while platform is also very important.

　　Common extrusion platforms are cement platform and steel structure platform.

　　Cement platform

　　Advantages: The foundation is very solid. We can understand the cement platform as the ground. It’s necessary if the machine with extremely high stability requirements.

　　Disadvantages: Once the machine is relocated, it has to be abandoned.

　　Steel structure platform

　　The cost is very high, lots of points should be considered, such as uniform force distribution, reasonable maintenance space, solid foundation and so on. If there are four extruders, then it will take at least RMB200,000. But, still lots of customers will ignore the value that a good steel platform will bring.

　　The difference of platform will cause different machine stability especially after several years. The coordination between the steel platform foundation and the ground is also very important, which are limited by ground concrete thickness, the level, floor board specifications, fixation of expansion screws and so on.

　　Normally, the cast film line requires a minimum thickness of 20cm for workshop concrete. To achieve better stability, the manufacturer will provide the foundation diagram, and the customer will lay an iron plate under the column foot and guide rail as a load-bearing pad according to the diagram.

　　It’s necessary to calibrate the equipment level within 3 months. If there is a deviation, slightly adjusted by the anchor bolts.

　　Another problem is resonance.

　　Sometimes, there is shaking when machine reaches a certain speed even the platform is solid and no problem of the motor assembly. When over this certain speed, the shaking will decrease or disappear. This is called as resonance.

　　Resonance nodes are different on each machine, even same machine possibly with different resonance nodes. There is no good solution for resonance nodes. Usually, we will start the machine by missing this resonance node in the early stage. And after long-term working, the resonance nodes will disappear or decrease a lot .

　　High barrier cast film line has high requirements for platform. If there are defects of the platform at the design stage, then it would be difficult to finish this project.

　　Since there are EVOH, PA, PP and some other material, and related to different film structures, so there are many extruders. If it is 11 layers co-extrusion high barrier film, there will be around 10sets extruders. It’s a challenge for the engineers to make layouts for so many extruders. There is big difference of the extruder volume and weight. The force points are staggered, engineers should consider the overall gravity distribution of the whole extrusion system.

　　Also engineers should consider maintenance space. The space should be reasonable used, meanwhile shorten the melt pipeline as much as possible.

　　Besides, high barrier film line will be equipped with very complicated material feeding system, such as weighing, mixing and drying. How can the extruder cooperate well with the feeding system It is also very important and we will talk about this in future articles.

　　If you want to learn more about cast film line, don’t hesitate to contact us.