(1) The temperature of each section of the plastic sheet production equipment cylinder is gradually increased from the feeding section to the connection between the cylinder and the molding mold.

(2) molding mold temperature is slightly higher than the cylinder temperature. The higher temperature is controlled at 5- - -10℃. The temperature at both ends of the mold is slightly higher than what temperature in the mold, and the temperature is controlled at 5-10℃.

(3) In the form of entry, the middle roll surface of the three rolls shall be as horizontal as the lower plane of the mold lip surface is parallel to the center line of the center roll, 50~100mm. apart

(4) The mold lip gap shall be slightly less than or equal to the thickness of the plate products, and the middle mold lip gap shall be slightly less than the end mold lip gap on both sides.

(5) Note that R roughness of three-roller working surface shall not be greater than 0. 2pm. When cleaning the roll surface, a copper knife shall be used to clean the residual material.

(6) The roller surface shall have some medium height; the gap between the three rollers shall be equal to or slightly greater than the thickness of the plate.

The temperature control of the (7) molding mold shall be stable. The melt flows faster in the die when the temperature is high; the melt flow speed slows down in the die when the temperature is low. Unsteady melt flow rate causes a large longitudinal thickness error of the plate (sheet) product.

(8) Pay attention to control the working surface temperature of the three rollers, the inlet roller temperature should be slightly higher and the outlet roller temperature should be slightly lower. Roll surface temperature is too high, the slab is not easy to roll off, the product surface can easily produce transverse lines; the temperature is low, the product surface is not shiny. According to this phenomenon, the roller surface temperature control should be adjusted in time.

The operation speed of the (9) three-rolls is slightly higher than the extrusion speed of the slab from the mold mouth, and the general speed difference does not exceed 10%. The working speed of the three rolls should be controlled smoothly, and the too fast or too slow running speed has a great impact on the thickness error of the plate.

When (10) polyolefin plastic extrusion molding sheet (sheet), the screw adopts a mutant structure, the compression ratio is (3-4): 1, the melt flow rate is: HDPE 0.  3~2.0g/10min,LDPE 0.1~0.3g/1Omin,PP 0.5~1. 5g/10min. The extrusion plate (sheet) (ABS) shall be selected with compression ratio (1.612.5): 1.

Exextrusion molding of (11) plastic plates (sheets), such as ABS, polyamide and polypropylene resin (etc.) shall be dehumidified and dry before extrusion. Otherwise, extrusion shall be made using an exhaust extruder.