The CPP film is a polypropylene (PP) film produced by a cast extrusion process in the plastics industry. This type of film is different from a BOPP (bidirectional polypropylene) film and is a non-oriented film. CPP film has the characteristics of good transparency, high gloss, good stiffness, good moisture resistance, excellent heat resistance, and easy heat sealing. CPP film has been printed and bagged, and is widely used in clothing, knitwear and flower packaging bags, document and photo album films, food packaging and metallized films suitable for barrier packaging and decoration. In addition, there is an increasing demand for food packaging, candy packaging (twisted film), pharmaceutical packaging (infusion bags), self-adhesive tapes, business card holders, and ring folders.
CPP film is excellent in heat resistance. Since the softening point of PP is approximately 140°C, this type of film is used in hot filling, cooking bags, aseptic packaging and other fields. The combination of acid resistance, alkali resistance, and excellent grease resistance make it the preferred material for bread packaging or laminates. It is safe in contact with food, demonstrating excellent performance, does not affect the flavor of the interior food, and can select different grades of resin to obtain the desired characteristics.
China's CPP film started in the 1980s and has just begun to introduce single-layer casting equipment from abroad. Its width is only 1m to 1.5m, and its annual production capacity is about 1,000 tons/tablet to 1,500 tons/set. In the 1990s, a multi-layer coextrusion cast film line was introduced from the Austrian Lansing Company, Mitsubishi Heavy Industries Japan, Reifenhauser Germany, W&H, Colines, Italy, Dolci, Battenfeld, USA, etc., with a width of 2m to 2.5m and an annual production capacity of 3,000 tons. / Taiwan ~ 4000 tons / Taiwan. Since 2000, the company has been making rapid progress and has introduced more advanced production lines, mainly multi-layer co-extruded cast film production lines with a width of 4m to 4.5m and an annual production capacity of 5,000 tons/table to 6,000 tons/tablet. Among them, Foshan Plastics Group Co., Ltd. introduced the standard production line of David in the United States with a width of 5.4m and an annual production capacity of 11,000 tons. At the same time, domestic equipment has also developed rapidly. According to incomplete statistics, by the end of 2006, China's CPP film introduction production line exceeded 77, with a production capacity of more than 390,000 tons; domestic production lines exceeded 150, with a production capacity exceeding 260,000 tons, and the total production capacity exceeded 650,000 tons. According to the industry survey, the demand for CPP film nationwide in 2006 was close to 400,000 tons, and the demand in 2008 was 500,000 tons.
We are facing a market environment with severe oversupply and fierce competition. Each company needs a good attitude and knows itself to choose its own correct competition strategy. In response to a variety of competitive forces, some CPP companies have explored three major successes. Strategy: Total cost leadership strategy, product differentiation strategy and product specific strategy. The author believes that large companies with multiple production lines or small companies with strong research and development capabilities may consider adopting product differentiation strategies. The following is a brief description of the differentiated products and their development direction of CPP films.
1. Application of composite membrane: According to the sealing temperature (conditions: 0.18MPa, 1S, ≥1N/15mm), it can be divided into normal composite membrane (<140°C), low-temperature heat sealing composite membrane (<115°C), and ultra-low temperature heat. Seal the composite membrane (<100°C). The BOPP/CPP (or BOPET/CPP) two-layer film is generally compounded with a printed BOPP film or a BOPET film for packaging of clothing, dried foods, and puffed foods. Its development direction is: (1) high transparency, good opening performance, high smoothness (COF<0.2 after aging), low heat sealing temperature, etc. to meet the requirements of high-speed bag making and packaging; (2) maintaining the film The surface wetting tension is up to 38 dyne for 6 months to extend the shelf life of the product.
2. Aluminized film substrate uses: With its low cost, the aluminum-plated product has excellent properties such as excellent shading, decorative, barrier properties, etc., and has good adaptability in post-processing such as printing, compounding, etc. It meets the requirements of heat resistance, chemical resistance, wear resistance, oxygen resistance, high barrier, etc. It is widely used in food packaging and other decorative fields. Its development direction is: (1) to improve the stiffness to improve the quality of the product's aluminum plating; (2) the adhesion of the aluminum layer after plating is up to 2N/15mm to meet the needs of large packaging; (3) to improve the aluminum layer after plating Temperature resistance, adapt to 300°C extrusion compounding requirement (currently only reach 240°C or so), increase peel strength 1N/15mm or more; (4) reduce heat sealing temperature, less than 110°C, heat seal strength ≥ 1N /15mm, to meet the requirements of high-speed automatic packaging; (5) to improve the opening and smoothness to meet the requirements of high-speed bag and packaging, because can not add slip agent, etc., the current general product COF is about 0.75; ( 6) How to maintain the wetting tension on the surface of the aluminum layer up to 38 dyne for 6 months to extend the shelf life of the product is a problem; (7) With the large-scale aluminum plating machine, the ultra-long ultra-wide aluminum plated substrate becomes inevitable The development direction of the company, such as part of a product with a width of 2500mm and a length of 24000mm, has been normalized. 3. Cooking film uses: According to the temperature conditions can be divided into: ordinary cooking film (105 °C ~ 115 °C, time 20min ~ 30min), medium temperature cooking film (about 121 °C, 30min ~ 40min), high temperature cooking film (135 °C, 30min); compounded with barrier films such as PET, PA, aluminum foil, etc., used to package products that require high-temperature cooking, such as meat, juice, agricultural products, and medical supplies. The important performance index of CPP cooking film is heat sealing strength, impact strength, composite strength, etc., especially the above indicators after cooking. In addition, the film is odorless or contains a very low odor is its direction of development, such as chestnut bags and other odor requirements for CPP film is very strict.
4. Audio and video products, album membrane use: CPP film with its low cost, environmental protection, transparency, heat seal, tear resistance and other properties are widely used in audio and video products packaging and photo albums, folders, business card holders and other production. High transparency, high gloss and abrasion resistance are the direction of its development.
5. Use of paper towel film: CPP film is widely used for square, small, strip, paper roll and copying of sanitary tissue because of its stiffness, wear-resistance, transparency and printability superior to that of PE film for high-speed printing and packaging. Automatic packaging of paper and other products. Increasing the stiffness to reduce the thickness, improve the wear resistance and maintain the surface tension is its development direction.
6. Table printing single-layer food packaging film uses: mainly used for bread, biscuits and other foods of various small packaging; high stiffness, high transparency, smooth, wear, high surface wetting tension and adapt to high-speed automatic packaging is Direction of development.
7. Self-adhesive film use: According to the demand can produce transparent, white, paper or other color film, mainly for stickers, products or aviation signs, baby diaper labels, etc.; high stiffness, high surface finish Wet tension and easy die cutting are the direction of its development.
8. Twisted conjunctiva use: CPP film because its density is much smaller than PVC, PET, PS and cellophane, much less equipment investment, so the cost per unit area is lower; can be surface printing, aluminum plating, can also be directly heat sealed , Plus environmental hygiene, is an ideal material for kink packaging such as candy, chocolate, and beef jerky. Improve the kink, stiffness, transparency and gloss is its direction of development.
9. Use of protective film: Due to its advantages of low cost, transparency, high stiffness, etc., it partially replaces PET and BOPP films as protective films for inkjet advertising, cold laminating films and other products.
10. Breathable cling film purpose: CPP film has superior moisture resistance and oxygen permeation rate of 2000cm3/m2. d. Bar, the moisture resistance reaches 5000cm3/m2 through modification. d. Bar~6000cm3/m2. d. Bar, plus its ability to heat seal, single-layer use as an ideal packaging material for vegetables, fruits and a variety of edible fungi. According to the different contents of the package, adjusting the 02/C02 permeation and antibacterial is its development direction.
11. Non-transparent microporous breathable film Application: In the production of CPP film, appropriate pore-forming additives are added and stretched at a certain temperature. The CPP film becomes a gas-permeable film with a certain pore size. At present, films with different breathability have been widely used in medical and health care films (such as sanitary napkins, sterile protective film), microfiltration membranes, and papermaking for people.
12. Antistatic film purposes: CPP antistatic film can be divided into moisture-absorbing antistatic film and permanent antistatic film, surface resistivity of 108Ω ~ 1010Ω, can be applied to a variety of electronic components packaging. The annual sales of China's electronic information industry is 2.4 trillion yuan, which requires a variety of anti-static films. This is a broad market. The surface resistivity reaches 1010 Ω to 1012 Ω, which is suitable for high-speed powders that are not automatically packaged.
13. Anti-fog film use: used for fresh fruits, vegetables, salads, edible fungi and other packaging, clearly see the contents when refrigerated, and prevent food spoilage. CPP thin requires good anti-fog effect (cold and hot state can prevent fog), high heat seal strength and good low-temperature flexibility, etc. No odor or low odor is its development direction.
14. Packaged flower film Application: CPP film can be individually used for packaging of flowers after printing and bag making, and the properties such as film transparency, antistatic property and customer specified friction coefficient can be adjusted as needed.
15. Use of medical membranes: The production line is required to be installed in a sterile room to prevent the product from being contaminated in any form, and does not contain hygienic properties such as the generation of harmful substance migration. After aluminizing, it is combined with BOPP, PET, BOPA, etc. as a packaging for tablets or powders; it is co-extruded with high-barrier materials such as EVOH to produce infusion bags and blood collection bags.
16. Use of pesticide coating: Through the use of special materials for modification, the solvent resistance, heat-sealing strength and impact resistance of CPP film are greatly improved. It is applied to the packaging of pesticides such as emulsifiable concentrates. The usual flexible packaging structure is CPP/AL/BOPET. And CPP/PET aluminum/BOPET.
17. Use of high barrier co-extruded film: The use of PP with good water-blocking properties and PA, EVOH, etc. with oxygen barrier properties for the co-extrusion production of high barrier films are widely used in meat frozen products, cooking meat food packaging Its good oil resistance, organic solvent resistance, can be widely used in edible oil, convenience foods, dairy products, rust-proof hardware products, packaging; its good moisture barrier moisture, can be used for alcohol, soy sauce and other liquid packaging.
18. Co-extruded film with PE Use: Through the modified CPP film, LDPE and other film materials can be directly used for extrusion compounding, which not only ensures the fastness of extrusion composite, but also reduces the cost of compounding.
19. Highly transparent and flexible film. Use: Through the use of co-extrusion and blending technology, CPP film has high transparency, high impact resistance, has a very soft hand, excellent resistance to puncture and low temperature performance, is mainly used Food packaging frozen and stored after cooking is also used in packaging such as high-grade clothing, T-shirts and underwear, and can also be used for other heavy packaging.
20. Straight easy tear film Application: The CPP film produced by the modified PP and special production process has straight-line easy-tear properties, and is made into a variety of straight-line tear-away bags with other materials to facilitate consumers' use.
21. Easy-peel film use: As the usual CPP film has a high heat-sealing strength, the heat-sealed flexible pouch is not easy to open. Generally, it is necessary to mark the edge of the pouch to open the package. Through the modification of the heat seal layer PP, the easily peelable CPP film can be combined with BOPP, BOPET, BOPA, aluminum foil and other packaging materials to become easily peelable packaging. After heat sealing, it can be pulled directly from the heat sealing edge, which is very convenient. The consumer's use is now commonly used in jelly lids and dairy products.
22. Matte Film Application: The surface gloss of CPP matt film is ≤10%. It has a matte glass-like surface optical effect. After printing, the color is saturated, the feel is comfortable, and the appearance is elegant. It can be used for heat sealing, and can also be used for compounding. It is suitable for packaging high-quality sanitary napkins and foods.
23. The use of biodegradable membranes: The CPP degradation film made from the production of degradable masterbatch is added to PP, and it can be degraded into inorganic substances and absorbed by the soil in about 7 months to 12 months under natural conditions. At present, some European companies have successfully developed such mothers.