Blow molding processing wholesale film production process is generally as follows:

Hopper feeding of material → plasticizing extrusion → blowing and stretching → air ring cooling → V-shaped clamp → traction roller traction → corona treatment → film winding

However, it is worth noting that the performance of blown film in the blow molding process is highly related to the production process parameters. Therefore, during the blowing process, strict control of process parameters is essential, standardized operation is required, and smooth production must be ensured to obtain high-quality film products. In the production of polyethylene blown film for wholesale, the main aspects of process parameter control include:

Extruder temperature

During blow molding processing of low-density polyethylene (LDPE) film, the extrusion temperature is typically maintained between 160℃ and 170℃, ensuring uniform die head temperature. Excessive extrusion temperature can lead to resin decomposition and脆 film, particularly with a significant decrease in longitudinal tensile strength; whereas, too low a temperature results in poor resin plasticization, preventing smooth expansion and stretching. The film's tensile strength is lower, and its surface luster and transparency are poor, possibly developing patterns resembling wood grain and unfused crystal nuclei (fish eyes).

2. Blowing Ratio

Blow-up ratio is one of the key control points in the production process of blown film for blow molding wholesale, referring to the ratio between the diameter of the blown film bubble after inflation and the diameter of the unblown tube ring. The blow-up ratio represents the lateral expansion multiple of the film, which is essentially a lateral stretch that 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 cause instability in the film bubble and lead to wrinkles in the film. Therefore, it should be properly coordinated with the draw ratio. Generally, the blow-up ratio for low-density polyethylene (LDPE) film should be controlled between 2.5 and 3.0.

Blow-molding wholesale products produce pollutants.

During the blow molding and wholesale processing, plastic granules emit a small amount of organic waste gas due to high temperatures, with the main component being non-total hydrocarbons.