Film blowing machine manufacturers have high standards and requirements for the selection of films. Today, Hebei Ningjin Ruixing plastic machinery brings me the selection and characteristics of films.

1. The selected raw material should be polyethylene resin particles of blown film grade, containing an appropriate amount of smoothing agent to ensure the opening of the film.

2. If the melt index (MI) of the resin particles is too large, the viscosity of the molten resin is too small, the processing range is too narrow, the processing conditions are difficult to control, the film-forming property of the resin is poor, and it is not easy to process the film; in addition, if the melt index (MI) is too large, the relative molecular weight distribution of the polymer is too narrow, and the strength of the film is poor. Therefore, it is necessary to select the resin raw materials with low melt index (MI) and wide relative molecular weight distribution, which can not only meet the performance requirements of the film, but also ensure the processing characteristics of the resin. Polyethylene materials with melt index (MI) in the range of 2-6g / 10min are generally used for blown polyethylene film.

Key points of blow molding process control

The process flow of blown film is as follows:

Hopper feeding - material plasticizing extrusion → blowing traction → air ring cooling → herringbone splint → traction by traction roller → corona treatment → film winding

However, it is worth noting that the performance of blown film has a great relationship with the production process parameters. Therefore, in the process of blown film, we must strengthen the control of process parameters, standardize the process operation, ensure the smooth production, and obtain high-quality film products.