Four-in-one film and multi-layer heavy bag film were successfully developed

Gansu Jinchang Jinchuan Wanfang Industrial Co., Ltd. made use of its own advantages and the successful development of four-in-one membranes and three-seven-layer composite bag membranes in a number of universities and national research institutes within the United Nations.

Heavy bags made of these two kinds of films have been successfully used to package Jinchuan Group's salt products and Nickel's nickel sulfate and nickel oxide.

According to reports, the four-in-one film is made of plastic braided cloth, PE film, BOPP film, and calendered film by casting a double film head coating process. The outer laminated film is printed first and then combined with a pearlescent film. This film can be used to make high-grade bags.

The 3-7-layer composite heavy bag film is made of PE, PP, EVA, PVDC for each layer of material, using a multi-layer co-extrusion blowing process made of multi-layer co-extruded film. In particular, the co-extrusion process of PVDC resin as an intermediate layer with other types of resins overcomes the difficulty of PVDC alone extrusion molding.

The main development results of Jinchuan Wanfang Company's four-in-one high-grade bag membranes and 3-7-layer composite heavy-bag membranes are: First, the selected coating resin meets the requirements for a solid composite with the plastic-woven cloth. Second, the best process parameters for temperature control in each zone of the single-screw extruder and the T-die are obtained. Third, the front and back of the film are accurately positioned at high speed. Fourth, PP woven fabric flat yarn specifications and ratio preferred. Fifth, the selection of dry composite adhesives resistant to 280 °C high temperature. 6. Selection of leakproof bottom materials and development of back cover equipment.

Jinchuan Wanfang Company also cooperated with Reifenhauser GmbH in Germany to introduce advanced technologies and components. In the co-extrusion blown film equipment, multi-layer coextrusion taper superimposed streamline die, IBC internal cooling, rotary traction and other high-tech devices were used.

Co-extrusion blowing equipment developed by the company can produce multi-layer high barriers with symmetrical and asymmetrical structures. At the same time, the company also designed and manufactured a back-sealing device suitable for both types of membranes.

According to the company, both films have a 30% reduction in production costs compared to conventional dry compound films, and they all achieve solvent-free residue and cleanliness.