BOPP is known as the packaging queen in the plastic film industry and plays a pivotal role in the plastic flexible packaging industry. Since the late 1970s, the categories of BOPP have also been continuously enriched, adding luster to the plastic world. BOPP product classification is divided into light film, dull film, pearlescent film, aluminized film, laser film and so on. Light film: BOPP ordinary film, also known as light film, is the largest amount of BOPP products. The light film itself is a waterproof plastic film, and through the coating film, the surface of the label material that is not waterproof can be turned into waterproof; The light film makes the surface of the label stickers more bright, more high-end and attractive; The light film protects the printed ink/content, making the label surface scratch-resistant and more durable. Therefore, light film is widely used in all kinds of printing, food, goods packaging.
Features: 1. The light film has the characteristics of waterproof; 2. The light film makes the surface of the label bright; 3. Light film can protect the printed content.
Use: 1. Printing articles; 2. Packaging of food and articles.
Matte film: also known as matte film, mainly through the absorption and scattering of light to achieve the effect of extinction, generally can improve the quality of the printed appearance, but the price is relatively high, and there are fewer domestic manufacturers, so it is often used in boxed food or high-end packaging. The matting film often has no heat sealing layer, so it is used in combination with other films (such as CPP, BOPET).
Features: 1. Can make the film show matte effect; 2. The price is relatively high; 3. No heat sealing layer.
Usage: 1. Boxed video; 2. High-end packaging.
Pearlized film: more than 3 layers of co-extruded stretch film, the surface will generally have a heat sealing layer, common such as chopsticks bag, often the pearlized film has its own heat sealing layer heat sealing, so there will be a hot sealing section. The density of the pearlescent film is mostly controlled below 0.7, which is conducive to cost saving; And the common pearlescent film presents a white, opaque pearlescent effect, has a certain ability to block light, and has a protective effect on products that need to avoid light. Of course, pearlescent film is also often combined with other film used in food and daily necessities, such as ice cream, chocolate packaging and beverage bottle labels.
Features: 1. The surface generally has a heat sealing layer; 2. The density is mostly below 0.7; 3. White, translucent pearlescent effect; 4. Has a certain ability to block light.
Uses: 1. Food packaging; 2. Beverage bottle label.
Aluminum plating film: Aluminum plating film is a kind of composite flexible packaging material formed by using a special process to coat the surface of the plastic film with an extremely thin layer of metal aluminum, of which the most commonly used processing method is vacuum aluminum plating method, so that the surface of the plastic film has a metallic luster. Because it has the characteristics of plastic film, but also has the characteristics of metal, is a cheap and beautiful, excellent performance, practical packaging materials, mainly used in biscuits and other dry, puffed food packaging and some medicine, cosmetics on the outer packaging.
Features: 1. The surface of the film has an extremely thin layer of metal aluminum; 2. The surface has a metallic luster; 3. It is a cheap, beautiful, good performance and practical composite flexible packaging material.
Uses: 1. Biscuit and other dry, puffed food packaging; 2. Outer packaging of medicine and cosmetics.
Laser film: Using computer dot matrix lithography, 3D true color holography, multiple and dynamic imaging and other technologies, the holographic image with rainbow dynamic, three-dimensional effect is transferred to the BOPP film, which is resistant to ink erosion, high water vapor blocking ability, and better anti-static. Laser film in the domestic production is relatively small, the production technology has certain requirements, generally used for high-end goods anti-counterfeiting, decorative packaging, such as cigarettes, drugs, food and other packaging boxes.
Features: 1. Resistance to ink erosion, high water vapor blocking ability;
2. Better anti-static.
Use: 1. Anti-counterfeiting packaging of high-end products;
2. Cigarette, medicine, food and other packaging boxes.
Advantages: BOPP film colorless, tasteless, non-toxic, and has high tensile strength, impact strength, rigidity, toughness and good transparency and other advantages. Corona treatment is required for BOPP films before gluing or printing. After corona treatment, BOPP film has good printing adaptability, can be color printing and get exquisite appearance effect, so it is commonly used as the surface material of composite film.
Shortcomings: BOPP film also has shortcomings, such as easy to accumulate static electricity, poor heat sealing performance. In addition, the initiation tear strength of the BOPP film is increased after stretching, but the secondary tear strength is very low, so the two ends of the BOPP film can not leave any incision, otherwise the BOPP film is easy to tear when printing and composite.
1. On the general packaging machine, static electricity can be transferred through the rapid conduction of metal or static eliminator;
2. Add antistatic agent and antistatic masterbatch in BOPP film production process;
3. The high humidity environment is also conducive to the elimination of static electricity on the surface of the film.
In the case of relatively large electrostatic film or dry season (such as winter), enterprises can put the film into the packaging workshop in advance, adjust the humidity of the packaging workshop, and also use water to wet the workshop floor or wet towel applied to the end face of the film roll to improve the humidity of the environment and eliminate the static electricity on the surface of the film.
1. Wide heat sealing temperature range, so that the film has a good heat sealing adaptability, can ensure its smooth operation in various packaging machines. Therefore, the heat sealing temperature of BOPP film should generally be controlled between 85 and 110℃.
2. The special heat sealing materials used by film production enterprises are generally ethylene-propylene binary copolymer, ethylene-ethylene-butyl terpolymer and their mixtures, and different heat sealing materials should be selected at different packaging speeds when the film production formula is designed.
3. The heat sealing strength of BOPP film is also related to the thickness of the heat sealing layer, and the thickness of the heat sealing layer should be controlled according to the use needs in actual production.