Waterproof Greaseproof PE Coated Cup Stock Paper Raw Material Bottom Lamination Paper Roll

This is a highly automated continuous production process that typically includes the following key steps:

• Unwinding: A huge roll of raw paper is installed on the unwinding rack, smoothly unfolded, and fed into the production line.
• Corona treatment: This is a crucial step. The chemical properties of polyethylene and paper differ greatly, and direct composite adhesion is poor. Corona treatment is the process of generating micro roughness and polarity on the surface of paper through high-voltage discharge, greatly increasing the surface energy of the paper and allowing the melted PE to better "wet" and "grasp" the surface of the paper.
• Extrusion plasticization: Food grade polyethylene resin particles are added to the hopper of the extruder. The extruder has a heating zone and a rotating screw inside, which heats, pressurizes, and melts PE particles into a uniform, viscous fluid. This process is called "plasticization".
• Mold head coating: Molten PE is transported to a long, precise T-shaped mold head. The slit opening of the mold head can be adjusted as needed to control the coating thickness. PE flows out evenly from the narrow slit of the mold like a curtain.
• Compression and cooling:
  • Compression: The PE melt film flowing down from the die is pressed together with the surface of the paper that has undergone corona treatment in the gap between the cooling roller and the pressure roller.
  • Cooling: The cooling roller (usually with circulating ice water inside) quickly cools the PE from a molten state above 200 ° C to a solid state, making it firmly adhere to the paper.
• Roll up: After completing single-sided film coating, the paper can be fed into the second film coating machine for coating on the other side (to produce double-sided PE paper), or rolled up directly to become a huge PE film coating paper mother roll.