Bending deformation of plastic profile is the most common quality failure in its extrusion production process. Its severity is often different due to the different plastic material structure and die wear. If the corresponding measures are not taken, the profile products with qualified quality cannot be produced. Analysis of the causes of bending deformation of plastic profiles and related solutions:
I. Prerequisites for solving the bending deformation of plastic profiles: the concentricity and horizontality of the extruder, extruder, die, shaping die, and traction machine. If the alignment is not performed before production, it will cause concentricity among several people. After the plastic profile is extruded from the die, the plastic profile is gradually transformed from the molten state to the highly elastic and glassy state. Under the action of its bending stress, bending deformation will inevitably occur.
Second, the key to solving the bending deformation of plastic profiles is to deal with the uneven discharge of the die. First of all, the die should be carefully assembled before the extrusion is started to ensure that the die is shunted and centered. The gaps between the parts are uniform. When tightening the bolts between the joint die plate, the head and the die, the force should be uniform. If the die is not uniformly discharged when the extrusion is started, the die temperature should be adjusted accordingly according to the bending deformation direction of the parison. That is to reduce the bending deformation of the parison and the temperature on the side subjected to the tensile stress. If the adjustment is invalid, it should be stopped and re-disassembled, assembled or repaired the die according to the situation. According to the direction and speed of material deflection, the method of "blocking" and "grooming" should be used to repair the die, and the angle of the partial flow of the die is appropriately adjusted. Repairing the die should be progressive in order, and do not rush to achieve success, excessive repair. The working quality of the mold is closely related to the bending deformation of the plastic profile. The quality of the mold working force is a dynamic index. It changes gradually with the length of the production cycle, the number of mold replacements, the amount of wear, and the quality of maintenance and repair work, which is not static. As a plastic profile production and management staff,
In the daily production process, you should understand and be familiar with the work and wear characteristics of the mold, pay close attention to the quality of the mold work, and make good monitoring records.