Blow molding film processing wholesale process generally includes:
Hopper feeding of one material → plasticizing extrusion → blowing and stretching → air ring cooling → V-shaped plate → roller traction → corona treatment → film winding
However, it is worth noting that the performance of blow molding processed wholesale film is greatly related to the production process parameters. Therefore, during the blowing film process, it is essential to strengthen the control of process parameters, standardize process operations, ensure the smooth progress of production, and obtain high-quality film products. In the production of polyethylene blow molding processed wholesale film, the main aspects of process parameter control include:
Extruder temperature
When extruding low-density polyethylene (LDPE) film in blow molding, the extrusion temperature is generally maintained between 160℃ and 170℃, and it is essential to ensure uniform die head temperature. Overheating can cause resin decomposition, making the film brittle and significantly reducing its longitudinal tensile strength. On the other hand, if the temperature is too low, the resin will not be properly plasticized, preventing smooth expansion and stretching. The film will have lower tensile strength, poor surface luster and transparency, and may even exhibit wood grain patterns and unmelted crystal nuclei (fish eyes).
2. Blowing Ratio
Blow-up ratio is one of the key control points in the blow molding process for wholesale film production, referring to the ratio between the diameter of the film bubble after inflation and the diameter of the un-inflated tube ring. The blow-up ratio represents the lateral expansion multiple of the film and, in fact, involves stretching the film laterally, which exerts a certain degree of orientation on the plastic molecules. As the blow-up ratio increases, it enhances the lateral strength of the film. However, the blow-up ratio should not be too high, as it may lead to unstable film bubbles and more frequent wrinkling. Therefore, it is necessary to coordinate the blow-up ratio with the draw ratio appropriately. Generally speaking, the blow-up ratio for low-density polyethylene (LDPE) film should be controlled between 2.5 and 3.0.
Blow molding wholesale products generate pollutants.
During the blow molding processing and wholesale processing, plastic pellets generate a small amount of organic waste gas due to high temperatures, with the main component being non-total hydrocarbons.
