Blow molding film processing wholesale process generally includes:

Hopper feeding of 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 blown film processing in bulk is greatly related to production process parameters. Therefore, during the blowing film process, it is essential to strengthen control over process parameters, standardize process operations, and ensure smooth production as well as high-quality film products. In the production of polyethylene blown film processing in bulk, the control of the following process parameters is mainly focused on:

Extruder temperature

During the blow molding process for low-density polyethylene (LDPE) film, the extrusion temperature is typically maintained between 160℃ and 170℃, ensuring uniform die head temperature. Excessive extrusion temperature can cause resin decomposition and make the film脆，significantly reducing the longitudinal tensile strength. On the other hand, insufficient temperature leads to poor resin plasticization, preventing smooth expansion and stretching. The film's tensile strength is lower, with poor surface luster and transparency, and may even exhibit patterns resembling wood grain as well as unmelted crystal nuclei (fish eyes).

2. Blowing Ratio

Blow-up ratio is one of the key control points in the production process of blowing film for bulk wholesale, referring to the ratio of the diameter of the blown film bubble to the diameter of the unblown tube ring. The blow-up ratio represents the lateral expansion multiple of the film, which is essentially a lateral stretching of the film. This stretching exerts a certain degree of orientation on the plastic molecules, increasing the lateral strength of the film as the blow-up ratio rises. However, the blow-up ratio should not be too high, as it can lead to instability in the film bubble and the film may wrinkle easily. Therefore, the blow-up ratio should be appropriately matched with the draw ratio. 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' generated pollutants

During the blow molding and wholesale processing, plastic pellets volatilize at high temperatures, producing a small amount of organic waste gas, the main component of which is non-total hydrocarbons.