Electrostatic causes and elimination methods of BOPP, BOPET and BOPA films

BOPP tobacco packaging film is a kind of film with higher technical content in BOPP film. Compared with ordinary BOPP thin film, it has higher elastic modulus, tensile strength, stiffness, optical properties, heat sealing strength, antistatic properties, etc.

Antistatic property is a important standard to measure the quality of tobacco film. The film with static electricity is easy to absorb dust, so that the surface of the film is dirty: static electricity affects the normal operation of film production, serious will hurt the operator: electrostatic film affects the normal production of cigarette packaging machine, cigarette pack appears pulling line, borrowing, long Angle, packaging is not compact, serious flying bag phenomenon affects the normal production of tobacco factory. It can be seen that eliminating static electricity is of great significance for BOPP smoke film.

First, BOPP smoke film electrostatic mechanism:BOPP film and other commercial molecular materials, have excellent insulation performance. The chemical bonds of polypropylene molecules in the material are covalent bonds, which are not easy to ionize and cannot transfer electron ions, so that the surface of the film has a high surface resistance. When different materials touch and rub together, they accumulate a large amount of electrostatic charge on the surface. When two materials are separated, each material has a certain amount of positive (negative) charge.

Two, the principle and method of electrostatic elimination rod to eliminate static electricity:

Electrostatic eliminator has induction type, DC discharge type, AC discharge type, etc. BOPP production line, film cutting equipment, tobacco packaging machines will use electrostatic eliminator to eliminate static electricity. The advantages of electrostatic eliminator are convenient to use, low price and easy to operate: the disadvantage is that it is only applicable to the surface of the film electrostatic large, partial elimination of the surface static electricity.

1. Induction type electric eliminator: is a kind of grounded conductive electronic brush, through the electronic brush close to the charged film, the tip of the ionized air, generated and charged film electric type of the opposite charge and the film with the charge neutralization, and charged film electric charge is through the electronic brush into the ground, so as to eliminate static electricity. This type of static eliminator is commonly used in BOPP winders. Can release part of the film production process of static electricity.
2. Dc discharge electrostatic eliminator: is a needle electrode, the opposite electrode through the direct current between the needle electrode and the film corona discharge, produce ions of opposite polarity, neutralize the surface charge of the film. Some cigarette packaging equipment strip packaging part will use such electrostatic eliminator.
3. AC discharge electrostatic eliminator: It is widely used in film scutters by forming capacitive coupling body, periodically generating ions and attracting ions to eliminate static electricity.

Second, the influence of static electricity on the use of smoke film and emergency methods

There are two main ways of BOPP smoke film static electricity: 1, BOPP film production process due to the friction between the film and the equipment generated static electricity; 2. Static electricity generated by friction between finished cigarette film and cigarette machine packaging equipment in the process of use.

After the production of tobacco film is completed and sent to the tobacco factory, the sensitivity of the packaging process to static electricity is also different due to the differences in environmental changes and packaging equipment.

1. Impact of different environmental changes: geographical locations are different. Tobacco factories located in northern inland areas are often troubled by the problem of film static electricity due to the dry climate, especially in winter: tobacco factories located in coastal areas along the river are relatively humid, and the thin mold is not easy to produce static electricity. When the environmental conditions of smoke film production and use are very different, it is particularly important to control the temperature and humidity of smoke film storage and use. Cigarette materials are used more, cigarette paper, rosin paper and other requirements of drying conditions, and cigarette film requirements of large humidity conditions, more difficult to balance, generally with the temperature of 30C, 60% degeneration is appropriate.
2. Impact of equipment differences: At present, there are a variety of packaging equipment in the tobacco industry, including GD, BE, FOKER and other packaging equipment. The machine speed generally ranges from 180-400 packs/minute, and even some of the equipment can reach 600 packs/minute. Generally speaking, the faster the packaging speed, the more sensitive to static electricity. For example, GD is packaged at a slow speed, and the effect of static electricity on the packaging is reflected in the irregular sealing of the top and bottom of the cigarette pack. After the speed is increased to a certain extent, the phenomenon of flying bag begins to appear, and the film cannot be used on the machine.