Common mistakes in condiment packaging bags in daily life
Today, Xiaobian wants to share with you: there are still some misunderstandings in the production and application of condiment bags.
For example, some soft bag factories produce incorrect material selection or composite material combination and unreasonable size of condiment bags for customers, causing complaints from customers, and customers may never trust the quality level of this soft bag factory.
'In order to avoid the occurrence of similar situations, Xiao Bian summarized the five major application misunderstandings in the production of food plastic flexible packaging.
First, polyethylene film should not be used as vegetable oil fried food or seasoning packaging bag PE (Polyethylene)
Plastic film is usually mixed with high pressure polyethylene, low pressure polyethylene and linear polyethylene in proportion to enhance or supplement the performance of the film in actual casting or blow molding. Although PE (Polyethylene)
Cling film has good air permeability, But PE will quickly penetrate, expand and change color after contacting vegetable oil.
For example, packaging food containing vegetable oil will not only greatly shorten the shelf life of food, but also contact vegetable oil for a long time. PE (Polyethylene)
Naphthalene in the film will precipitate and dissolve in vegetable oil, which is harmful to human health.
Therefore, PE film should not be used for packaging fried food and food containing vegetable oil, nor should it be used for packaging food containing oil, such as melon seeds, dried fruit seeds, nut seeds, etc.
Second, the five-layer co-extruded PE plastic film is not suitable for making milk seasoning bags co-extruded PE (Polyethylene)
Plastic film packaging is typical of Coextruded Plastic film packaging, such as milk packaging, dairy packaging, soy sauce and vinegar packaging, which are very popular in the current market, transparent non-printing vacuum or cooking packaging bags are also co-extruded plastic film packaging.
At present, although the milk packaging uses black and white co-extruded plastic film, the outside is white, the inside is black, but the shelf life has been extended.
However, if three layers of co-extruded plastic film are used, the shelf life shown on the package will rarely be reached due to the lack of barrier layers. With evoh (Ethylene/vinyl alcohol copolymer)Barrier layer and coated with PVA (Polyvinyl alcohol)
The plastic film co-extrusion of the barrier layer can prolong the shelf life, but the cost is higher.
Three, plastic flexible packaging vacuum aluminized film can not replace aluminum metal aluminum foil, metal aluminum foil has shiny metallic luster, non-toxic and tasteless, good shading performance, reflectivity stable at 95 ℃ and low temperature, at 73-Does not expand or shrink at 371 ° C;
Good barrier property, gas barrier property, oxygen barrier property, moisture resistance and fragrance preservation property are excellent intermediate layer base films for high-grade packaging.
It is mainly used for advanced packaging and blister packaging of medicines, advanced packaging of chocolate, sealing and covering film of instant noodle bowls, paper/aluminum/plastic composite packaging of milk, dairy products and fruit juice, food and condiments high-grade fragrance packaging, cooked meat products, cooking packaging of braised chicken and roast duck, moisture-proof and antistatic packaging of integrated circuit boards, etc.
Although the aluminized plastic film has good mechanical properties, the surface is smooth and bright, it is not easy to produce pinholes, it has strong decoration, and has certain gas resistance, light protection and shielding functions, it can make up for the defects of low strength, easy tearing, easy cracking when folding, easy pinhole formation and poor acid and alkali resistance of vacuum aluminized plastic film aluminum layer, which will fall off when wet, and dealuminization will lead to the opening of the composite packaging bag.
In addition, the aluminum layer is too thin, that is to say, only about 50,000 of high-purity aluminum is needed for a plastic film plated with 1 kg, and its shading and shielding properties are far lower than those of rolled aluminum foil (Pure metal aluminum foil).
Therefore, in the use of plastic composite packaging substrates, aluminized films cannot replace rolled aluminum foil. Fourth, pet (Polyester)Film cannot replace pa (Nylon)
The film is used for cooking and packaging. The Function of cooking and packaging is to kill fungi in the packaged food through high cooking temperature and extend the shelf life of the packaged food.
Fungi can only be killed when high temperature is transferred to food in the package through the package. Pa (Nylon)
The film has high water vapor transmission rate, and the metal aluminum foil is a good heat conductor.
However has excellent insulation performance and good gas barrier performance of pet (Polyester)
Films do not have good thermal conductivity and their water vapor permeability is very low, which can prevent the introduction of some or lower cooking temperatures. In addition, pet (Polyester)
The film has high hardness and is not easy to discharge air.
Although they have excellent barrier properties, they weaken the cooking and sterilization effects. Therefore, pet (Polyester)
The film can only be vacuum packed and cannot be cooked and packaged.
Five, paper-plastic composite film packaging is not necessarily environmentally friendly paper-plastic composite film packaging is paper-plastic composite packaging, usually through paper-plastic PE (Polyethylene)And PP (Polypropylene)Composite processing technology is compounded (Dry compound processing cost is higher).
Paper-plastic packaging is superior to plastic packaging in terms of air permeability, water resistance and barrier property, so it is often used for packaging items that need to release and absorb moisture, such as camphor inner packaging and moisture-proof agent (Desiccant)Packaging.
Paper can only be heat sealed and made into bags after being compounded with plastic, but it is not easy to recover or decompose naturally after being compounded with plastic.
In addition, the raw material for papermaking is wood, which is also a waste of natural resources.
Therefore, some people think that paper-plastic composite packaging is more environmentally friendly than plastic packaging.