How to solve the problem of bending deformation in the extrusion of u-PVC profile?
Bending deformation of PVC profiles is a common problem in the extrusion process, and its causes are mainly: uneven discharge of material from the mouth die; inadequate cooling of materials and inconsistent post-shrinkage when cooling and shaping; equipment and other factors.
1. Ensure the concentricity and level of the whole line of the extruder, and correct the concentricity and level of the extruder, mouth die, sizing die and water tank at each die change.
2. Assemble the mouth die carefully before starting the machine to make the gap of each part consistent. If the uneven material discharge from the mouth die is found when starting the machine, adjust the temperature of the mouth die according to the bending and deformation direction of the billet to ensure the uniform material discharge from the mouth die, if adjusting the temperature of the mouth die is not effective, the plasticization degree of the material can be increased appropriately.
3. Adjust the cooling system of the shaping mold and increase the cooling water on the side of the profile bearing tensile stress.
4. Adjust the method of mechanical offset center, that is, while producing, adjust the positioning bolt in the middle of the shaping mold, and make reverse micro adjustment according to the direction of profile bending (the method should be adopted with caution, and the adjustment amount should not be too large).
5. Pay close attention to the working quality of the mold, pay attention to the maintenance of the mold, and maintain and repair the mold at any time according to the actual situation.
