Blow molding film processing wholesale process generally involves the following steps:

Hopper feeding of material → Plasticizing extrusion → Blowing and stretching → Air ring cooling → V-plate → Roller traction → Corona treatment → Film winding

However, it is worth noting that the performance of blow molding processed bulk film is highly related to the production process parameters. Therefore, during the film blowing process, strict control over process parameters must be enforced, standardized process operations must be followed, and the smooth progress of production must be guaranteed to obtain high-quality film products. In the production of polyethylene blow molding bulk film, the following process parameters should be well-controlled:

Extruder temperature

During the blow molding process for low-density polyethylene (LDPE) film, the extrusion temperature is generally maintained between 160℃ and 170℃, and it is essential to ensure uniform die head temperature. Excessive extrusion temperature can cause resin decomposition, making the film brittle and significantly reducing its longitudinal tensile strength. On the other hand, too low a temperature results in poor resin plasticization, preventing smooth expansion and stretching, leading to lower tensile strength of the film. Additionally, the film's surface will have poor luster and transparency, and may even exhibit wood grain patterns and unmelted crystal nuclei (fish eyes).

2. Blow-up Ratio

Blow-up ratio is one of the key control points in the production process of blown film for plastic processing wholesale, referring to the ratio between the diameter of the film bubble after blowing and the diameter of the unblown tube ring. The blow-up ratio represents the lateral expansion multiple of the film and, in essence, is a form of lateral stretching that exerts a certain degree of orientation on the plastic molecules. As the blow-up ratio increases, the lateral strength of the film also improves. However, the blow-up ratio should not be too high, as it may cause the film bubble to become unstable and lead to wrinkles in the film. Therefore, it should be properly coordinated 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 generate pollutants.

During the blow molding and wholesale processing, plastic pellets may volatilize at high temperatures, producing a small amount of organic waste gas, primarily composed of non-methane total hydrocarbons.