Biaxially oriented polypropylene film
DATE：2021/9/6 8:49:40 / READ： / SOURCE：This station
Biaxially oriented polypropylene film
Biaxially oriented polypropylene film (BOPP) has the advantages of light weight, transparency, non-toxicity, moisture resistance, and water resistance. It has good thermal stability, chemical stability and electrical properties, so it is used in food, candy, cigarettes, tea, medicine, It is widely used in the packaging of juice, milk, textiles, etc., as well as in the production of electrical appliances and adhesive tapes. In recent years, the production of BOP adopts a new seven-layer co-extrusion technology, which enables BOP to be evenly distributed in the central gas barrier layer with propylene-butadiene copolymer, effectively blocking oxygen, carbon dioxide, water vapor and other corrosive substances. Entering people has greatly increased the anti-corrosion ability of the packaged objects and prolonged the storage period of the objects. Therefore, people gave this BOPP film with a gas barrier layer the reputation of "Packaging Queen".
1. Main raw materials
BOPP film is made of isotactic PP as the main raw material, according to different products and uses, with 3% to 5% of additive masterbatch. The raw material should be sea film P homopolymer, and should have the following characteristics: ①Melt flow rate is 1.5-4.0g/0min; ②Isotacticity is 5%～98%; ③Water content <0.03%; ④Ash content < 0.2×10-3. Additives are auxiliary components for film making, and erucamide type lubricants, ethylenediamine type antistatic agents and antifreeze agents containing silicon oxide particles are generally used to improve the surface properties of the product.
2. Main equipment and basic process flow
The equipment is mainly manufactured by a professional company of BOPP automatic production line. Companies that can provide a complete set of BOPP equipment technology include: Japan's Mitsubishi Heavy (MT-SUBISHI) and Toshiba (TOSHIBA); France (CELLIER); German Bruckner (BRUCKNER), Lenzing (LENZING) and Guan Guo Ma Su (MARSALI) )Wait. Among these competitive technologies, Mitsubishi Heavy Industries and Bruckner are more advanced in technology. Mitsubishi Heavy Industries' technology is characterized by Shenlian twin-screw extrusion and multi-roll cooling molding; Bruckner is known for its multi-machine co-extrusion, dual-cylinder filter large roll water bath chilling, and rational use of additives. Mitsubishi Heavy Industries' twin-screw joint extrusion has good plasticization, uniform and stable pressure, small lateral shrinkage of thick sheets, and good tolerances of thick sheets. However, the multi-roll cooling process conditions are narrow, the cooling is slow, and large-scale high-speed production is restricted. Bruckner's multi-machine co-extrusion, using different extruder combinations and matching die heads, can produce light film and multi-layer film; adopts double-cylinder filter device, which can replace the filter during production; adopts large roller internal cooling In addition to water dissolution, the molten material can quickly pass through the crystallization temperature zone and be quenched to room temperature, which is conducive to high-speed and large-scale production; using additives to adjust the formula, the product has great variability and good film performance.
3. The production of BOPP film is carried out according to the following basic process
PP→Extrusion→Filtration→Die head forming→Quick cold casting→Thickness measurement→Longitudinal stretching→Horizontal stretching→Edge trimming→Film thickness measurement→Corona treatment→Rewinding aging treatment→Slitting and packaging.
Author：admin