The blowing film process in plastic molding wholesale is generally as follows:

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

However, it is worth noting that the performance of blow molding 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 the operation, and ensure the smooth progress of production to obtain high-quality film products. In the production of polyethylene blow molding wholesale film, the following process parameters need to be controlled effectively:

Extruder temperature

During blow molding of low-density polyethylene (LDPE) film, the extrusion temperature is typically maintained between 160℃ and 170℃, and it is crucial to ensure uniform die head temperature. Excessive extrusion temperature can lead to resin decomposition and脆化的film, particularly 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, with possible wood grain-like 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 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, with an increased blow-up ratio enhancing the film's lateral strength. However, the blow-up ratio should not be too high, as it can lead to unstable bubbles and the film may wrinkle easily. Therefore, the blow-up ratio 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 produce pollutants.

During the blow molding and wholesale processing, plastic pellets may emit a small amount of organic waste gas due to high temperatures, primarily composed of non-total hydrocarbons.