Wuhan modern extrusion casting film
日期：2021/3/22 8:30:37 / 阅读： / 来源：本站
Wuhan modern extrusion casting film
Hollow board production line www.handern.com
The performance of plastic packaging film is not only related to the raw and auxiliary materials and the ratio used, but also has a great relationship with the production process of the film. Using the same resin and formula, the film produced by different processes has great differences in performance. In order to obtain high-performance packaging materials, it is necessary to adopt appropriate production process according to different use conditions. Hollow board production line www.handern.com
The processes of producing plastic packaging film include expansion film, castfilm, solution cast film, orientation film and calender film. Generally speaking, we call the film whose thickness is less than 0.3mm, sheet whose thickness is 0.3 ~ 0.7mm and plate whose thickness is more than 0.7mm. Hollow board production line www.handern.com
The characteristics of film and sheet production by extrusion tape casting are as follows: first, high yield, which can reach 120 ~ 150m / min, because the cooling rate is faster than other methods (blowing method); Secondly, generally speaking, the film produced by extrusion tape casting has good transparency, because the film is immediately quenched with water bath or quench roller after it is cast from T-die, which reduces the crystallinity of crystalline polymer and improves the transparency; Thirdly, the tape casting film is the best one in the film for heat sealing. Because there are no directional molecules in the film, the film will lose its heat sealing property. Therefore, as the inner sealing material of the composite film, the tape casting film is the best choice; Fourth, in principle, the tape casting film is not stretched by the traction force in the production process, so the performance of the film in the longitudinal and transverse directions is balanced or relatively balanced; fifth, the uniformity of the size and thickness of the tape casting film is better. Hollow board production line www.handern.com
In order to improve the adhesion of hot silver to plastics, besides corona treatment, the surface of plastic film should also be pre treated with primer. The materials used for primer are very common, such as natural and synthetic rubber, all kinds of resins with medium and high polarity. Some units use ink to carry out vacuum lead plating after printing, and the effect is also very good. However, due to the high temperature, it is easy to mix with the oxygen in the resin containing oxygen In order to protect the aluminum surface after vacuum plating, the top coating of two-component polyurethane adhesive should be carried out on the aluminum, and the complete aluminum plating process can be completed.
PE (oriented and non oriented), PP (oriented and non oriented), pet, rigid PVC, PC, PS, nylon (biaxially oriented), Eval, polyethylene, quanjiasheng and synthetic paper can be used as vacuum aluminized substrates. In addition, the paper should be treated under vacuum to recover its toughness.
The characteristics of vacuum aluminizing film are as follows: first, it has beautiful metallic luster, good decoration effect, the correct choice of substrate film and primer can get the coating of light selective mirror; second, it improves the gas and humidity resistance of the original substrate film, and improves the fragrance retention; third, it can block ultraviolet and visible light; fourth, due to the conductivity of aluminum. It can reduce all kinds of hazards caused by static electricity and improve the operability of vegetable coating: fifth, it has good printing and lamination adaptability; sixth, it improves the bending resistance of the film and reduces the pinhole caused by bending.