What is the reason for the relaxation of the film in the blowing machine
Uneven thickness of the film: If the thickness of the film is uneven over the entire length or width, it can cause tension in some areas to be greater than in other areas during the winding process, resulting in local uneven tension. This is usually related to the performance of the extruder, the configuration of the screws, and the distribution of raw materials.
Improper cooling of the bubble cooling air ring: During the blowing process, a cooling air ring is used to quickly cool the thermoplastic bubble. If the cooling effect of the wind ring is uneven, it may cause certain parts of the film bubble to cool too quickly or too slowly, affecting the physical properties and uniformity of the film material.
Local cooling of the membrane bubble before entering the clamp: If the membrane bubble cools locally in a certain area before coming into contact with the clamp, it will cause inconsistent performance of the material in this area, resulting in uneven tension during winding.
Inconsistency between the mold mouth and the center of the traction roller: If the mold mouth of the blowing machine (i.e. the plastic film outlet) is not aligned with the centerline of the traction roller, the film will be subjected to uneven tension during the traction process, resulting in relaxation or deformation.
When cutting the edge with the cutting blade, the cutting edge and angle are inconsistent: In the film production process, the cutting operation needs to be very precise. If the cutting edge of the cutter is worn unevenly or the angle is set improperly, the cutting edge will be uneven, affecting the overall flatness of the winding.
Inconsistent pressure on the pressure roller during winding: The winding pressure roller is used to ensure the tightness and flatness of the film during the winding process. If the pressure setting of the pressure roller is uneven or there is a malfunction, it can cause the film to relax or become too tight.
Uneven seam of the stabilizing plate: The stabilizing plate is used to maintain the stability of the film before it enters the winding process. If the seam is uneven, the film may be subjected to uneven force when passing through the stabilizing plate, thereby affecting the final winding quality.
