1、 Technical principles and material characteristics
Material characteristics
CPP film: made of polypropylene material, with high transparency, low temperature resistance, and easy heat sealing properties, commonly used in food packaging and composite film substrates.
CPE film: made of polyethylene material, with good flexibility and chemical corrosion resistance, suitable for medical packaging, industrial protection and other fields.
Principles of Casting Process
After the plastic particles are melted and plasticized by an extruder, they flow out uniformly through the die to form a molten film, which is quickly cooled and shaped by contact with a cooling roller, and finally rolled into a roll.
2、 The entire process of the production line
raw material preparation
Plastic pellets (CPP/CPE) are mixed with additives to ensure material uniformity and stability.
Extrusion plasticization
Single/twin-screw extruder: plasticizes plastics at high temperatures (160-220 ℃) to form a uniform melt.
Screen changer and metering pump: filter impurities and stabilize extrusion pressure.
Tape Casting
Mold head design: T-shaped mold head or hanger mold head, controlling the width and thickness of the film.
Cooling roller: Teflon coated roller surface, quickly cools the molten film to a glassy state.
Roll up and slitting
Automatic thickness measurement and cutting: Cut waste edges according to preset specifications.
Tension control winding: Constant tension winding ensures that the film roll is flat.
3、 Core equipment composition
Extrusion System
Screw extruder: single screw or twin-screw design, suitable for different material characteristics.
Mold head: precision machining to ensure uniform film thickness (0.02-0.12mm).
Cooling and shaping
Cooling roller group: Multiple rollers work together to improve cooling efficiency.
Wind knife system: Positive and negative pressure wind knives optimize the flatness of the film surface.
Automated control
PLC control system: integrated monitoring of temperature, speed, tension and other parameters.
Online detection equipment: thickness gauge, defect detector to ensure product quality.

application area
Food packaging: CPP film is used for packaging pastries and fresh food trays; CPE film is used for packaging medical devices.
Industrial protection: CPE film is used for electronic dust-proof clothing and chemical protective clothing.
Special functional films: aluminum plated film, steaming film, barrier film, etc.