The hottest food packaging is widely used. What re

Food packaging is widely used. What requirements should meat products packaging have?

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core tip: the purpose of packaging is to prevent bacterial contamination of products, so as to ensure product quality. Packaging can also play an advertising role and attract consumers' attention. In all stages of manufacturing, circulation, sales and consumption, that is, from the factory to the hands of consumers, products always have to contact hands, so pollution may occur at any time, so we should prevent bacterial pollution through packaging

[China Packaging News] the purpose of packaging is to prevent bacterial contamination of products, so as to ensure product quality. Packaging can also play an advertising role and attract consumers' attention. In all stages of manufacturing, circulation, sales and consumption, that is, from the factory to the hands of consumers, products always have to contact hands, so pollution may occur at any time, so we should prevent bacterial pollution through packaging

most of the packaging materials used in meat products are plastic. Plastic has a wider range of packaging properties than paper, metal and other packaging materials. A packaging material can have several properties at the same time. Moreover, the lamination and pasting or coating technology of plastic thin glands can also supplement the insufficient performance of single films, and the lamination/coating technology can be used to develop films for various purposes

oxygen isolation

is the permeability of isolating oxygen. Not only oxygen, but also other gases. The amount of gas passing through the plastic film has nothing to do with the molecular size of the gas. Usually, it is carried out in two steps: first, the gas is dissolved in the molecules of the film, and then infiltrated through diffusion. The oxygen resistance of the film is applicable to the packaging of all meat products except raw meat. Especially in vacuum packaging and inflatable packaging. Due to the role of oxygen, hemoglobin is changed into heme, causing product discoloration, promoting fat oxidation and the proliferation of aerobic microorganisms. Therefore, preventing the product from contacting with oxygen is extremely important for maintaining product quality and improving preservation

moisture resistance

is the property of blocking the passage of water vapor. When the film molecules do not contain hydrophilic hydroxyl and carboxyl groups, it is considered to have good moisture resistance. Moisture resistance changes greatly with temperature. The moisture resistance of the film is applicable to all meat products packaging. If the moisture of the product penetrates from the inside of the packaging film in the form of water vapor, or the product absorbs the water vapor from the outside, the flavor, organization and content of the product will also change. Especially for the packaging of dry sausages with little moisture, and to prevent the natural loss of quantitative products is extremely important

blackout

especially for the 320 ~ 380 nm wavelength light with optical effect in ultraviolet light. This property is very important for vacuum packaged sliced products, colored products and smoked products. The transparent film has no effect of blocking ultraviolet rays. Although HDPE has some shading properties, the film is opaque. There are many ways to prevent ultraviolet transmission, one of which is to add ultraviolet absorbent to packaging materials. However, in recent years, the use of UV absorbers in food packaging materials has been banned. Therefore, a method of shading by using the properties of light has been developed. This method uses printing ink to absorb or reflect light, or satin processing roller to mechanically extrude concave convex patterns on the film surface to reflect light. When using printing inks to promote the plastic industry to move towards the high end, black and white can absorb or reflect light. In addition, other inks, even with light and dark color difference, can not achieve the desired effect. Except for black, all light colors have almost no effect of absorbing light. Dark colors, according to black, blue, green and yellow, have poor shading in turn, while red and purple have no effect. Generally, when printing, the film with shading effect is opaque, and the disadvantage is that the products in the packaging bag cannot be seen. In order to make up for the defects of opaque films, a method of ultra micronization of ink has been developed recently, which uses the scattering of ultraviolet light with relatively short wavelength inside the film to block light, so that the longer wavelength visible light can pass through, and the printed film of the products in the packaging bag can be seen

impact resistance

in this case, △ e=[r1r2/(r1+r2) 2] △ r1/r1- △ r2/r2+ △ r3/r3- △ r4/r4) U properties are applicable to all packages. Especially for heavy things, tight packaging without gaps between casings and products is more important. The impact resistance of packaging materials can be ensured by the balance of tensile strength, tensile elongation and impact strength of materials. Such films include polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, stretched nylon, etc

cold resistance

even at low temperature, the film is not brittle, and can still maintain its strength and impact resistance. Generally, there is no problem in preserving meat products at -10 ~ 0 ℃, but if frozen meat products are preserved at -15 ℃, the cold resistance of the film must be considered, because it directly affects the sealing strength. Cold resistant packaging includes polyamide resin, polyethylene (low density), polyester, polypropylene (tensile), polypropylene (non tensile), etc

heat resistance

refers to the property that the softening point is high and does not deform even after heating, and the ownership of the power station can be transferred to the lessor (such as PVC). Since the product expands when heated, the heat-resistant strength of the film must be guaranteed. This property is suitable for packaging for secondary sterilization. Polyester, polyvinylidene chloride, polypropylene (no stretching), polypropylene (stretching) and polyethylene (high density) have good heat resistance

formability

refers to the nature of blowing the heated and softened film into shape (pneumatic forming) with air, or forming the film along the forming die (forming along the product in compact packaging) by suction (vacuum forming). Good formability means that the four sides of the heated film can be stretched evenly with a small force