Application and development of the hottest CPP fil

Application and development of CPP film

CPP film is a polypropylene (PP) film produced by tape casting and extrusion process in the plastic industry. This kind of film is different from BOPP (bidirectional polypropylene) film and belongs to 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. After printing and bag making, CPP film is widely used in clothing, knitwear and flower packaging bags, document and album films, food packaging and metallized films suitable for barrier packaging and decoration. In addition, the demand for food packaging, candy packaging (twisted film), drug packaging (infusion bags), self-adhesive tapes, business cards, ring folders and other aspects is increasing

cpp film has excellent heat resistance. Since the softening point of PP is about 140 ℃, this kind of film is used in hot filling, cooking bags, sterile packaging and other fields. In addition, it has excellent acid, alkali and grease resistance, making it the preferred material in the field of bread product packaging or laminating materials. It is safe to contact with food, has excellent demonstration performance, and will not affect the flavor of the inner food. Different grades of resins can be selected to obtain the required characteristics

China's CPP film started in the 1980s, and has just introduced single-layer casting equipment from abroad. It is only 1m ~ 1.5m wide, and the annual production capacity is about 1000 ~ 1500 tons/set. In the 1990s, multi-layer coextrusion casting film production lines with a width of 2m ~ 2.5m and an annual production capacity of 3000 ~ 4000 tons/set were introduced from Lanjing company in Austria, Mitsubishi Heavy Industry in Japan, reifenhauser in Germany, W & H, colines in Italy, Dolci, Battenfeld in the United States, etc. Since 2000, more advanced production lines have been introduced, mainly multi-layer coextrusion casting film production lines with a width of 4m ~ 4.5m and an annual production capacity of 5000 ~ 6000 tons/set. Among them, Foshan Plastics Group Co., Ltd. introduced the American David standard production line width of 5.4m, with an annual production capacity of 11000 tons. At the same time, domestic equipment has also developed rapidly. According to incomplete statistics, by the end of 2006, China had introduced more than 77 CPP film production lines with a production capacity of more than 390000 tons; There are more than 150 domestic lines, with a production capacity of more than 260000 tons, and a total production capacity of more than 650000 tons. According to the industry survey, the national demand for CPP film was close to 400000 tons in 2006 and 500000 tons in 2008

we are facing a serious oversupply and competitive market environment. Every enterprise needs to choose its own correct competitive strategy with a good attitude and know its own enemy. In the fight against a variety of competitive forces, some CPP enterprises have explored three successful strategies: total cost leadership strategy, product differentiation strategy and product specialization strategy. The author believes that large enterprises with multiple production lines or small enterprises with strong R & D capabilities can consider adopting product differentiation strategies. The following is a brief description of the differentiated products of CPP film and its development direction

1. Application of composite membrane: according to the sealing temperature (the condition is 0.18mpa, 1s, 1n/15mm), it can be divided into: ordinary composite membrane (140 ℃), low temperature heat sealing composite membrane (115 ℃), ultra-low temperature heat sealing composite membrane (100 ℃). Generally, it is combined with the printed BOPP film or BOPET film to form BOPP/CPP (or BOPET/CPP) two-layer film, which is used for the packaging of clothing materials, dry food and puffed food. Its development direction is: (1) high transparency, good opening performance, high smoothness (COF 0.2 after ripening), low heat sealing temperature to meet the requirements of high-speed bag making and packaging; (2) Keep the wetting tension of the film surface for more than 38 dynes for 6 months. The strain extensometer is composed of elastic elements and strain gauges pasted on it to extend the shelf life of the product

2. Application of aluminized film base material: with its low cost, aluminized products have excellent shading, decoration, barrier and other unique properties, and have good adaptability in printing, composite and other post-processing. It can meet the requirements of heat resistance, chemical resistance, wear resistance, oxygen resistance, high barrier and other applications, and is widely used in food packaging and other decorative fields. Its development direction is: (1) improve the stiffness to improve the aluminum plating quality of products; (2) The adhesion of the aluminum layer after plating is more than 2n/15mm, which meets the needs of large packaging; (3) Improve the temperature resistance of the aluminum layer after plating, meet the needs of 300 ℃ extrusion compounding (at present, it can only reach about 240 ℃), and improve the peel strength to more than 1n/15mm; (4) Reduce the heat sealing temperature, and the heat sealing strength is 1n/15mm under the condition of less than 110 ℃ to meet the requirements of high-speed automatic packaging; (5) Improve the opening and smoothness to meet the requirements of high-speed bag making and packaging. Due to the inability to add slippery agents, the COF of general products is about 0.75 at present; (6) How to maintain the surface wetting tension of aluminum layer for more than 38 dyne for 6 months to extend the shelf life of products is a difficult problem; (7) With the large-scale aluminizing machine, the ultra long and ultra wide aluminizing substrate has become an inevitable development direction. For example, some enterprises have normalized the production of products with a width of 2500mm and a length of 24000mm. 3. Purpose of cooking film: according to the temperature resistance, it can be divided into: ordinary cooking film (105 ℃ ~ 115 ℃, time 20min ~ 30min), medium temperature cooking film (about 121 ℃, 30min ~ 40min), high temperature cooking film (135 ℃, 30min); It is compounded with barrier films such as pet, PA, aluminum foil, etc., and used to package products that need high-temperature cooking and disinfection, such as meat, pulp, agricultural products and medical supplies. The important performance indexes of CPP cooking film are heat sealing strength, impact strength, composite strength, etc., especially after cooking. In addition, the film has no smell or contains very low smell, which is its development direction. For example, chestnut bags have very strict requirements on the smell of CPP film

4. Application of film for audio-visual products and Photo Albums: CPP film is widely used in the packaging of audio-visual products and the production of photo albums, folders, business cards, etc. because of its low cost and the ability to provide customers with a variety of high-performance products and services that can meet the future national policies and regulations on carbon dioxide emissions, such as protection, transparency, heat sealing, tear resistance, etc. High transparency, high gloss and wear resistance are its development direction

5. Application of tissue film: CPP film is widely used in the automatic packaging of square bags, small bags, strip bags, paper rolls, copy paper and other products of sanitary napkins because it is better than PE film in stiffness, wear resistance, transparency and printing performance, and is suitable for the requirements of high-speed printing and packaging. Increasing stiffness, reducing thickness, improving wear resistance and maintaining surface tension are its development direction

6. Application of surface printed single-layer food packaging film: mainly used for various small packages of bread, biscuits and other foods; High stiffness, high transparency, smoothness, wear resistance, high surface wetting tension and adaptability to high-speed automatic packaging are its development direction

7. Application of self-adhesive film: it can produce transparent, white, paper or other color films according to demand, which are mainly used for self-adhesive labels, products or aviation signs, baby diaper labels, etc; High stiffness, high surface wetting tension and easy die cutting are its development direction

8. The use of twisted film promotes the construction of intelligent manufacturing service platform: CPP film has a lower cost per unit area because its density is much smaller than PVC, pet, PS and cellophane, and the equipment investment is less; It can be printed on the surface, aluminized, or directly heat sealed. With environmental protection and sanitation, it is an ideal material for kink packaging of candy, chocolate, beef jerky and so on. Improving kink, stiffness, transparency and gloss is its development direction

9. Application of protective film: due to its low cost, transparency, high stiffness and other advantages, it partially replaces pet and BOPP film as the protective film of spray painting advertising, cold mounting film and other products

10. Application of breathable fresh-keeping film: CPP film has excellent moisture resistance, with an oxygen transmission of 2000cm3/m2.d.bar. Through modification, its moisture resistance reaches 5000cm3/m2.d.bar ~ 6000cm3/m2.d.bar. Coupled with its heat sealing properties, it can be used as an ideal packaging material for vegetables, fruits and various edible fungi in a single layer. According to the different contents of packaging, the development direction is to adjust the permeability of 02/C02 and antibacterial

11. Application of non transparent microporous breathable film: when adding appropriate pore forming additives in the production of CPP film and stretching at a certain temperature, CPP film becomes a breathable film with a certain aperture. At present, films with different permeability have been widely used in medical and health care films (such as sanitary napkins, sterile protective clothing films), microporous filtration films and artificial paper

12. Application of antistatic film: CPP antistatic film can be divided into hygroscopic antistatic film and permanent antistatic film, with a surface resistivity of 108 ~ 1010, which can be applied to the packaging of various electronic components. The annual sales volume of China's electronic information industry is 2.4 trillion yuan, and various antistatic films are needed, which is a broad market. The surface resistivity reaches 1010 ~ 1012, which can meet the requirements of automatic packaging of high-speed powder

13. Application of antifogging film: it is used for the packaging of fresh fruits, vegetables, salads, edible fungi, etc. the contents can be seen clearly when refrigerated, and it can prevent food from spoilage. CPP thin requires good antifogging effect (antifogging in cold and hot state), high heat sealing strength and low softness, etc. no odor or low odor is its development direction

14. Application of wrapping film: after printing and bag making, CPP film can be used separately for the outer packaging of flowers, etc. according to needs, the transparency, antistatic and customer specified friction coefficient of the film can be adjusted

15. Application of medical film: the production line is required to be installed in the sterile room to prevent the product from being polluted in any form, and does not contain sanitary properties such as the migration of harmful substances. After aluminizing, it is combined with BOPP, pet, BOPA, etc. as the packaging of tablets or powder drugs; Co extrude with high barrier materials such as EVOH to produce infusion bags, blood collection bags, etc

16. Application of pesticide coating: by modifying and using special materials, 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 soft packaging structure is CPP/Al/BOPET and CPP/Pet aluminized/BOPET

17. Application of high barrier coextrusion film: PP with good water resistance and PA, EVOH and other materials with oxygen resistance are used for coextrusion. The high barrier film is widely used in the packaging of frozen meat products and cooked meat food; Its good oil resistance and organic solvent resistance can be widely used in the packaging of edible oil, convenience food, dairy products and rust proof hardware products; With good water and moisture resistance, it can be used for liquor, soy sauce and other liquid packaging in case of range jump

18. Application of coextrusion film with PE: CPP film produced by modification can be extruded and compounded directly with LDPE and other film materials, which not only ensures the fastness of extrusion compounding, but also reduces the cost of compounding

19. Application of high transparent and flexible film: by using coextrusion and blending technology, CPP film has high transparency, high impact resistance, extremely soft hand feel, excellent puncture resistance and low temperature resistance. It is mainly used for food packaging after cooking and frozen storage, as well as packaging of high-grade clothing, T-shirts and underwear, as well as other heavy packaging

20. Application of linear tear film: CPP film produced by modified PP and special production process has linear tear property. It is compounded with other materials to make various linear tear bags, which is convenient for consumers

21. Application of easy peel film: because the usual CPP film has high heat sealing strength, the heat sealed soft packaging bag is not easy to open, and it is generally necessary to make a notch on the edge of the packaging bag to open the package. Through the modification of the heat sealing layer PP, the CPP film that is easy to peel is produced, which is combined with BOPP, BOPET, BOPA and aluminum