A plastic sheet extrusion machine is a type of thermoforming packaging equipment, primarily used for processing plastic materials such as PP, PE, PS, and PET. These products are widely used in stationery, blister packaging, and advertising. The production line consists of core components such as the main extruder, molds, and a three-roll calender, supporting single-layer or multi-layer co-extrusion processes.
This equipment uses a nitrided steel screw and barrel, equipped with a forced lubrication system. Sheet forming is achieved by controlling the melt temperature, mold gap, and roll pressure parameters. During production, the temperature gradient must be strictly controlled, with the mold and three-roll temperature deviation controlled within the range of 5-10℃, and the roll surface roughness required to be below 0.2μm. In terms of technological development, the equipment improves energy efficiency and biodegradable material processing capabilities through electromagnetic dynamic extruders and dual-stage single-screw technology, and enhances functionality through multi-layer composite co-extrusion technology. Domestically, environmentally friendly biodegradable sheet extrusion production lines have been developed, exploring the application of nanomaterials, while simultaneously reducing production costs through direct extrusion of powder using twin screws, adapting to the demand for high-barrier and high-transparency materials.
Precautions
(1) The temperature of each section of the barrel in the plastic sheet production equipment gradually increases from the feeding section to the connection between the barrel and the molding die.
(2) The temperature of the molding die is slightly higher than the temperature of the barrel. The temperature difference should be controlled within 5-10℃. The temperature at both ends of the die is slightly higher than the temperature at the center of the die, with the temperature difference controlled within 5-10℃.
(3) For sheet feeding, the upper surface of the middle roller of the three rollers should be on the same horizontal plane as the lower plane of the die lip; the end face of the lip should be parallel to the center line of the middle roller, with a distance of 50-100mm.
(4) The die lip gap should be slightly less than or equal to the thickness of the sheet product, and the gap between the middle and side lip edges should be slightly less than the gap between the two end lip edges.
(5) Note that the surface roughness R of the three rollers should not exceed 0.2 μm. When cleaning the roller surface, do not use a hard steel knife to scrape the roller surface; use a copper knife to clean the residual material on the roller surface.
(6) The roller surface should have some medium height; the gap between the three rollers should be equal to or slightly greater than the thickness of the sheet.
