Selection of the hottest soft can packaging materi

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Selection of soft can packaging materials

soft can packaging bag, also known as high-temperature cooking bag, is a soft packaging container made of multi-layer composite film composed of polyester, aluminum foil, polyolefin and other materials. With the improvement of the technical level, new materials are constantly emerging. At present, the high-temperature cooking bag composed of two layers and three layers is widely used. As for the three-layer composite bag, its inner layer is generally called the sealing layer. Polypropylene plastic

and polyethylene plastic are often used. These two kinds of plastics have the characteristics of low price and good sealing performance; The intermediate layer is a barrier layer to prevent the invasion of oxygen and harmful microorganisms. Aluminum foil, polyester plastic, nylon and other materials can be used; The outer layer is a reinforcing layer, which also plays the role of decoration and protection. Polyester plastic and

nylon can be selected. In fact, the high-temperature cooking bags currently used are the result of the combination of several film materials mentioned above. In terms of specific food, the following aspects should be considered when selecting the materials of high-temperature cooking bags

I. several factors to be considered in the selection of packaging materials

(I) shelf life. In order to prolong the shelf life of soft cans, good barrier property of bags is required. The former is used to block oxygen. The materials invaded by harmful microorganisms are mainly aluminum foil, polyester plastic and poly (acyl)

plastic. These three plastics have the best barrier property, followed by polyester plastic. If the shelf life of the product is less than one

month, any material can be selected. If the shelf life of the product is less than three months, only

aluminum foil and polyester plastic can be selected. If the shelf life is more than nine months, it is best to select aluminum foil as the barrier layer

theoretically, increasing the thickness of the plastic film can improve the barrier performance, but this increase is not

proportional, which cannot guarantee that the product has sufficient shelf life. If the thickness of the composite film is the same, the barrier property of the two

layers is not as good as that of the three layers, which is also a reason why we often use multi-layer composite films. For example, for the two combinations of polyester plastic/adhesive/polyethylene and polyester plastic/adhesive/polyester plastic/adhesive/polyethylene

olefin, if the thickness of the two composite films is the same, the barrier property of the latter is better than that of the former, and the latter should be preferred during use

(II) sterilization requirements. The plastic materials used in high-temperature cooking bags are different from the general metal materials under heating, because they do not have the melting point of fixed assets, but gradually soften with the increase of temperature. During the softening process, some plastic additives will melt out, affecting the quality of food. Therefore, high temperature resistance is an important indicator of plastic materials. The softening process of plastics is accompanied by the shortcomings of low strength drop and low sealing strength, which should be paid enough attention in use

the high-temperature resistance of the composite membrane material for high-temperature cooking bag is different. In the order from low to high, the recovery rate of low-pressure high-density polyethylene, modified polypropylene, polyester, polyamide and aluminum foil aluminum oxide is 93.05%. Different composite materials should be selected for different sterilization

temperatures. For high temperature sterilization less than 100 ℃, two-layer structure

should be selected, such as polyester/polyethylene; Nylon/polyethylene, etc. For high temperature sterilization below 120 ℃, three-layer structure can be selected, such as polyester/aluminum foil/modified polypropylene; Easy to overflow nylon/aluminum foil/modified polypropylene, etc

if the sterilization temperature is higher, a four-layer structure can be selected, such as polyester/aluminum foil/polyester/modified poly

propylene; Polyester/aluminum foil/nylon/modified polypropylene, etc

(III) price. The price of high-temperature cooking bags is made up of the prices of each layer of composite film. For composite bags that can meet both sterilization requirements and storage requirements, of course, the combination with lower price should be selected. For example, compared with the combination of polyester/adhesive/aluminum foil/adhesive/modified polypropylene and polyester/adhesive/

aluminum foil/adhesive/high-density polyethylene, the price of polyethylene is slightly lower than that of polypropylene, so the latter is often preferred in terms of price

the combination of different layers of materials will have different properties. Under the condition of meeting the sterilization and storage requirements

, the combination with less layers should be preferred

in addition, the same kind of plastic will have different high-temperature bearing capacity due to different additives or different processing technologies. If you do not pay attention to it during use, it is easy to cause quality accidents. For example, poly

ethylene plastic has four basic types according to different processing technologies. Only low-pressure high-density poly

ethylene has high-temperature resistance, and the rest cannot be used in high-temperature cooking bags

II. Selection of packaging materials for beverages

different high-temperature cooking bags should be selected for different beverage varieties. It is mainly determined by the above factors such as shelf life, sterilization temperature and price

(I) selection of packaging bags for acid drinks. Acidic drinks generally refer to

drinks with pH value below 4.5. Generally speaking, the pathogenic bacteria in the beverage can be basically killed after pasteurization of the acidic beverage.

during the storage period of the beverage, the pathogenic bacteria invading the beverage can not reproduce because the beverage is acidic, so the shelf life of the beverage can be extended from

. Therefore, the use of two-layer plastic composite bags for acid drinks can meet the requirements of

sterilization and preservation. The commonly used material combination of this bag is: Polyester/polyethylene; Nylon/polyethylene

ene; Polyester/polypropylene; Nylon/polypropylene, etc. Since the price of polyethylene is slightly

lower than that of polypropylene, the first two are preferred in use. Beverages suitable for these packages include blended yoghurt,

wild jujube juice, grape juice, sour soymilk, fruit tea, bayberry juice, etc. For drinks with long shelf life requirements,

the combination of polyester/aluminum foil/polyethylene can be used. Although the price is higher, the barrier property will be better

(II) selection of packaging materials for neutral beverages. The HP value of neutral drinks is above 4.5, so it is necessary to have a high sterilization temperature and good storage conditions. At present, the sterilization temperature of neutral drinks is mostly set at more than 120 ℃ when using domestic beneficiation facilities to produce lithium concentrate, which can basically kill the pathogenic bacteria in the drinks. If the oxygen and microorganisms are not invaded during storage, the purpose of long-term storage can be achieved. The packaging bags suitable for neutral drinks are: Polyester/aluminum foil/polypropylene; Polyester/aluminum foil/nylon/polypropylene; Nylon/aluminum foil/polypropylene; Polyester/aluminum

foil/polyester/polypropylene, etc

for neutral drinks with a shelf life of less than three months, some do not use aluminum foil as a barrier,

which can reduce the price of high-temperature cooking bags. Neutral beverages include: soymilk and soymilk, the selected beverage of Zhejiang Fengli waste plastic composite material recycling equipment, peanut milk, its peanut milk beverage, fresh milk and its beverage, sesame milk, etc

III. selection of packaging materials for meat food

there are many kinds of meat food and different processing technologies, which brings the diversity of high-temperature cooking bags, such as the packaging of ham sausage, the packaging of roast chicken, etc

for meat food, at present, aluminum foil and polypropylene or polyethylene are often used to make high-temperature cooking

bags. However, because aluminum foil is not suitable for printing, many enterprises often put a beautifully printed

bag outside the packaging bag to meet the needs of decoration. Although this packaging form has good display, it is not easy to prevent counterfeiting, and the cost is high. The best way is to use polyester/aluminum foil/polypropylene composite

bags, which not only have good printing performance, but also save costs

the selection of high-temperature cooking bag materials is a highly technical matter. There are many composite membrane materials that can be used for high-temperature cooking bags. There are many choices for different foods. Each material has its advantages and disadvantages. By combining two or more kinds of films, it can be obtained that can meet the requirements of sterilization and preservation

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