Usually, polyethylene PE and polypropylene PP plastic additives are used in film products and select special raw materials. Because the plastic melt of these two resins has good fluidity, it is easier to extrude and injection mold. As long as the process conditions (temperature, pressure, speed, etc.) are reasonably controlled, the production can be smoothly produced.
In order to prevent the resin from oxidation and degradation in the process of production and molding, plastic additives have been added before leaving the factory.
Therefore, for products with no special use requirements, there is no need to add any plastic additives to the resin during the production process. When there are special requirements for the working environment of the product, the following plastic additives should be added.
1. Select plastic auxiliaries according to their use
PE and PP products are used in working environments where they are often exposed to sunlight (UV). In order to prolong the use time and prevent rapid degradation and aging, a small amount of UV absorbent is added to the resin before production.
The commonly used UV absorber is 2-hydroxy-4-n-octanoxy benzophenone (UV531), adding 0.1% to 1.0%(mass fraction).
2. Antistatic masterbatch can eliminate the hidden danger of detonation
For PP or PE pipe used for conveying inflammable and explosive chemical articles, antistatic agent conductive carbon black or SN, HZ14, etc., should be added into the resin before production; The volume resistance of finished PE and PP tube should be less than 10∧9Ω·cm, in order to eliminate the hidden danger of ignition and detonation due to static electricity.
3. Some products require added flame retardants
Flammable PE and PP products. If the product is used in a special environment, flame retardants should be added before resin production to ensure safe use.
Common flame retardants include chlorinated paraffin with a mass fraction of more than 70% antimony trioxide (antimony white) and an equal amount of chlorine.
4. Slip masterbatch helps production
In order to reduce the friction between the molecules of the material in the extrusion cylinder and the excess heat generated by the friction between the plasticized melt and the cylinder and the die, a slip masterbatch and lubricant should be added to the formula.
But attention should be paid to the reasonableness of the amount added: excessive addition of Slip masterbatch will affect the plasticizing quality of the material; Excessive addition of external lubricants will not only affect product quality and output but also lead to precipitation of external lubricants at mold exit.