1. Add nucleating agent to the PE protective film particles.
The nucleating agent can replace the crystal nucleus during the processing of the crystalline polymer, so that the polymer molecules can grow into crystals on the nucleating agent. Due to the addition of the nucleating agent, the melt of the PE protective film and the PP protective film is at the melting point The number of crystal nuclei available for crystallization is greatly increased, the crystallization speed is accelerated, and the crystalline particles are refined, so that the crystal does not affect the transparency of the film, thereby increasing the crystallinity of the PE and PP films and improving the strength of the film, while increasing the transparency.
Nucleating agents are divided into two categories: organic nucleating agents and inorganic nucleating agents. Organic nucleating agents include benzoic acid and sodium benzoate, and inorganic nucleating agents include talc and sodium carbonate. The added amounts are sodium benzoate 0.25PHR, benzoic acid 0.4PHR, Na2CO30.2PHR, and talc 0.05PHR. For example, adding 0.3-0.7% calcium stearate nucleating agent to HDPE can increase the transparency of HDPE film from 67% to 73.5%.
2. Add 0.5-1% of homogeneous oil to the PE protective film particles.
This homogeneous oil can have good compatibility with PVC, PE, PP, PU, PC, PS, HIPS, ABS, AAS, PMMA, PET, PBT, etc., can be dyed with direct pigment powder to achieve uniform transparency. The colored plastic, and the homogeneous oil is non-toxic, only high-speed stirring at 50-70 ℃ can be used for molding processing.
3. The polyolefin transparent additive DBS can be added to the PE protective film.
It is a dibenzylidene sorbitol synthesized from sorbitol and benzaldehyde as raw materials. It is a nucleating agent specially used for polyolefins. It can reduce the haze of PP by 60% and LLDPE by 61%, and can improve Rigidity 8-10%, can also increase the heat resistance 9-10 ℃, increase the crystallization rate of PO more than twice, and also improve the film gloss and brightness.
4. In the production process of PE protective film, appropriately increase the processing temperature of the barrel and adopt the method of poly-cooling.
Can improve the transparency of the film. In fact, to produce transparent PP film, water quenching method must be used. If air cooling is used, the PP blown film produced is fuzzy and translucent due to poor cooling effect. For this reason, appropriately increasing the processing temperature in production and adopting high-efficiency cooling means are effective ways to improve transparency.
(5) Add a small amount of polyacrylate resin with good compatibility to PE protective film and PP protective film with good compatibility.
Understanding the method of improving the transparency of the protective film, we should also pay attention to such as; PE protective film does not cool quickly after crystallization, otherwise it will cause the original transparency of the protective film to be significantly reduced.