Film blowing machine manufacturers have high standards and requirements for the selection of film, and today Guangdong Yuesen Machinery has brought me the choice and characteristics of film.
1. The selected raw material should be a blown film grade polyethylene resin particle, containing an appropriate amount of smoothing agent to ensure the opening of the film.
2. The melt index (MI) of the resin particles can not be too large, the melt index (MI) is too large, the viscosity of the molten resin is too small, the processing range is narrow, the processing conditions are difficult to control, the film formation of the resin is poor, and it is not easy to process into film; In addition, 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, a resin raw material with a smaller melt index (MI) and a wider relative molecular weight distribution should be selected, so that the performance requirements of the film can be met and the processing characteristics of the resin can be ensured. Blow molded polyethylene film generally uses polyethylene raw materials with melting index (MI) in the range of 2 ~ 6g/10min.
Blow molding process control points
The blown film process is roughly as follows:
Material plasticizing extrusion → blowing traction → air ring cooling → herring-shaped splint → traction roll traction → corona treatment → film winding However, it is worth pointing out that the performance of blown film has a great relationship with the production process parameters, therefore, in the process of blowing film, it is necessary to strengthen the control of the process parameters, standardize the process operation, and ensure the smooth progress of production. And obtain high quality film products.