The high-temperature cooking bag is a composite plastic film bag that can be heated. It has the advantages of both canned containers and boiling water-resistant plastic bags. Therefore, it is also called “soft cans”. After more than ten years of use, it is proved to be an ideal packaging container for sales. The cooking bag is mostly made of three layers of materials. The typical structure of the cooking bag is: the outer layer is polyester film for reinforcement; the middle layer is aluminum foil for light, moisture and air leakage; the inner layer is polyolefin Film (such as polypropylene film) for heat sealing and food contact.
Today, the editor of Zekun will take you to popularize science about several materials and applicable fields of high-temperature cooking bags:
Can be used as a material for cooking bags
1. PET film
BOPET film is made of PET resin extruded by T film and then biaxially stretched. It has excellent performance.
(1) Good mechanical properties. The tensile strength of BOPET film is the highest among all plastic films. Very thin products can meet the needs, with strong rigidity and high hardness.
(2) Cold resistance and excellent heat resistance. The applicable temperature range of BOPET film is from 70 to 150°C, and it maintains excellent physical properties in a wide temperature range, which is suitable for most product packaging.
(3) Good barrier performance. It has excellent comprehensive water and gas barrier properties. Unlike nylon, which is more affected by humidity, its water blocking rate is similar to PE, and the air permeability coefficient is extremely small. It has extremely high barrier properties to air and odor, and is one of the fragrance-preserving materials.
(4) Chemical resistance, grease resistance and most solvents, dilute acids, dilute alkalis, etc.
2. BOPA film
BOPA film is a biaxially stretched film, which can be made by simultaneous biaxial stretching by a blow molding method. The film can also be biaxially stretched step by step by T-die extrusion method, and can be made by simultaneous bidirectional stretching by blow molding method. The characteristics of BOPA film are as follows:
(1) Excellent strength and toughness. The tensile strength, tear strength, impact strength and rupture strength of BOPA film are among the best plastic materials.
(2) Outstanding flexibility, pinhole resistance and not easy to pierce the contents are a major feature of BOPA. It has good flexibility and makes the packaging feel good.
(3) Good barrier properties, good fragrance retention, and resistance to chemicals other than strong acids, especially oil resistance.
(4) The temperature range is wide, the melting point is 225℃, and it can be used for a long time between -60~130℃. The mechanical properties of BOPA remain stable at low and high temperatures.
(5) The performance of BOPA film is greatly affected by humidity, especially dimensional stability and barrier properties. When BOPA film is damp, except for wrinkles, it generally stretches laterally. Longitudinal shortening, the elongation rate can reach up to 1%.
3. CPP film
CPP film is a cast polypropylene film, which is a non-stretched, non-oriented polypropylene film. According to the raw materials, it is divided into homo-CPP and copolymer CPP. The main raw material of cooking-grade CPP film is block copolymer impact-resistant polypropylene. The performance requirements are: the Vicat softening point temperature is greater than the cooking temperature, the impact resistance is good, the medium resistance is good, and the fish eyes and crystal points should be as few as possible.
4. Aluminum foil
Aluminum foil is the only metal foil among flexible packaging materials, used for packaging items that have a long application time. Aluminum foil is a metal material, and its water-blocking, gas-blocking, light-shielding and taste-preserving properties are unmatched by any other packaging material. It is a packaging material that cannot be completely replaced so far.
5. Ceramic Evaporated Film
Ceramic evaporation film is a new type of packaging film. It is a film obtained by using plastic film or paper as the substrate and vaporizing and vaporizing metal oxides on the surface of the substrate in a high vacuum equipment. The characteristics of the ceramic evaporation film are mainly:
(1) Excellent barrier properties, almost comparable to aluminum foil composite materials.
(2) Good transparency, microwave permeability, high temperature resistance, suitable for microwave food.
(3) Good fragrance retention. The effect is the same as glass packaging, and it will not produce peculiar smell after long-term storage or high temperature treatment.
(4) Good environmental protection. Low combustion heat, less residue after incineration.
6. Other films
(1) PEN film
The structure of PEN is similar to PET. PEN has various properties of PET, and almost all properties are higher than PET. Excellent comprehensive performance, high strength, good heat resistance, good barrier properties, transparency, and excellent UV barrier properties are PEN’s The biggest highlight, PEN’s barrier to water vapor is 3.5 times that of PET, and its barrier to various gases is four times that of PET.
(2) BOPI film
The operating temperature range of BOPI is extremely wide, reaching -269~400℃. The film that has been reacted has no melting point, and the glass transition temperature is between 360~410℃. It can be used continuously for more than 15 years at 250℃ in the air, and there is little change in performance. . BOPI has excellent comprehensive properties, high physical and mechanical properties, radiation resistance, chemical solvent resistance, dimensional stability, softness and folding resistance.
(3) PBT film
PBT film is one of thermoplastic polyester films, namely, butylene terephthalate film. The density is 1.31~1.34g/cm, the melting point is 225~228℃, and the glass transition temperature is 22~25℃. PBT film has better performance than PET film. PBT has excellent heat resistance, oil resistance, aroma retention and heat sealability, and is suitable for the production of microwave food packaging bags. PBT film has good barrier properties and can be used to package flavored food. PBT film has excellent chemical resistance.
(4) TPX film
TPX film is made by copolymerization of 4-methylpentene-1 and a small amount of 2-olefin (3%~5%). It is the lightest specific gravity among all plastics, only 0.83g/cm, and other properties are also very excellent. In addition, TPX has good heat resistance and is the material with the best heat resistance among polyolefins. It has a crystalline melting point of 235°C. It has good weak mechanical properties, high tensile modulus and low elongation, strong chemical resistance, oil resistance, and high acid resistance. , Alkali, water, resistance to most hydrocarbons, solvent resistance temperature up to 60℃, surpassing all other transparent plastics, high transparency, light transmittance of 98%, crystal clear appearance, strong decoration, and microwave penetration powerful.
Application field of high temperature cooking bag
To1. The packaging of various cooked meat products (vacuum bag packaging, heating stretch forming packaging, inert gas bag filling), the shelf life can be more than one month when stored at room temperature.
To2. Used for aseptic packaging of fresh milk, stored at room temperature, with a shelf life of 3 months.
To3. It does not use an aseptic packaging machine, but uses an ordinary liquid packaging machine for filling, and uses secondary sterilization of various fresh milk packaging, and the shelf life can reach more than 1 month at room temperature.
To4. Concentrated fruit juice, jam and vacuum aseptic packaging for long-term storage.
To5. Vacuum fresh-keeping small packages for fresh livestock and poultry meat, air-filled fresh-keeping small packages, and storage at room temperature for up to half a month.
To6.Packaging of various condiments with unique fragrance.
To7. Containing high protein and high fat, it has the properties of fragrant, crisp, puffing and brittle. During storage and circulation, no oxidative deterioration and no hygroscopicity and deliquescence are allowed in food packaging, such as baked food, coffee, and oatmeal. , Fried foods, especially fried fruits, etc.
To8. Packing of purified water, especially purified water for field operations and field operations.
To9. Packaging of medicines.
To10. Packaging of cosmetics.
To11. Packaging of precision industrial products such as machinery and electronics, especially the packaging of products that cannot be used for oil rust prevention stored in the sea and coastal areas.
Tol2. Packaging of chemical products and pesticides.
Tol3. It is combined with paper and cloth to make packaging with special performance and used in special occasions.
If you want to know more about food packaging bags, welcome to visit our company website：https://www.zekunpackaging.net or https://www.zekunpackaging.com