The blowing film process for plastic extrusion manufacturing is generally as follows:

Hopper feeding one material → plasticization extrusion → blow molding and stretching → air ring cooling → V-shaped plate → 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 blow molding and wholesale 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 a significant drop in longitudinal tensile strength; whereas, too low a temperature results in poor resin plasticization, inability to smoothly expand and stretch, lower film tensile strength, and poor surface gloss and transparency, even with 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 blowing film production process for wholesale film manufacturing, 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, and as the blow-up ratio increases, it enhances the film's lateral strength. However, the blow-up ratio should not be too high, as it can lead to instability in the film bubble and cause 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' generated pollutants

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