The blow molding process for wholesale film production generally follows this workflow:

Hopper feeding one material → plasticizing extrusion → blowing and stretching → wind ring cooling → V-shaped clamp → traction 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 focus is on controlling the following process parameters:

Extruder temperature

During the blow molding process of low-density polyethylene (LDPE) film, the extrusion temperature is generally maintained between 160℃ and 170℃, and it is crucial to ensure uniform die head temperature. Excessive extrusion temperature can lead to resin decomposition and脆化 of the film, particularly causing a significant decrease in longitudinal tensile strength; conversely, too low a temperature results in poor resin plasticization, preventing smooth expansion and stretching. The film's tensile strength is lower, and its surface gloss and transparency are poor, sometimes even developing wood grain patterns and unmelted 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 stretching of the film. This stretching exerts a certain degree of orientation on the plastic molecules, with an increased blow-up ratio enhancing the film's lateral strength. 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 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 generate pollutants.

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