Packaging development has experienced four distinct phases: the original bags, big bags, small bags, now gradually into the environmental protection (
A new stage of packaging bags.
With the development of commodity economy, the commercial of packaging itself also more and more significantly, it has become a no longer attached to the commodity production of special products, a kind of all the goods cannot leave, widely used products.
Chinese scientists developed a green plastic bags made of electrolyte, the environmental protection plastic bags can not only be harmless decomposition, and the environmental protection bags can dissolve in the water.
according to the scientists explain, in the life of common plastic polymer materials products, need hundreds of years of time to completely break down, there will be earth for hundreds of years.
According to the actual figures show that 80% after using plastic bags, and eventually generally be shipped to the same withdrawn dump trash, only seven percent of the plastic recycling use.
this kind of new environmental protection plastic bags in the decomposition process will not release harmful substances, and even into insect natural substances, and to protect the natural environment played a great help.
Packing bags of category: according to the material is often divided into plastic bags, composite bags.
plastic bags including plastic woven bag with a plastic film bag.
The former has characteristics such as light weight, high strength, corrosion resistance, after adding plastic film inner lining, is moistureproof prevent wet;
Light bag weight in 2.
Below 5 kg, medium-sized bag weight in 25
Heavy bags, 50 kg load - 50
The latter's light bag weight above 1 kg;
Medium-sized bag weight 1 -
10 - load heavy bag
More than 1000 kg bag container load.
Composite bags properties of different materials together, to improve the permeability of packaging materials, moisture permeability, oil resistance, water resistance and drug resistance, make it play a insect-resistant, dustproof, prevent microbes, such as light, sweet, smelly smell of isolation, as well as heat, cold resistant, impact resistance, better mechanical strength and processing performance, and have good printing and decoration effect.
- special packing
Insect-resistant packaging technology: bags insect-resistant packaging technology can be divided into the following five kinds: inflatable product, inflatable packaging packaging is use the inert gases such as carbon dioxide or nitrogen replacement packaging container in the air of a method of packaging technology therefore also known as the replacing packing.
This kind of packing method is based on aerobic microbial characteristics of aerobic metabolism, changes in the sealed container the composition of the gas, reduce the concentration of oxygen, inhibit the physiological activities of the microorganism, enzyme activity and the respiration intensity of fresh goods, achieve the goal of mouldproof, antisepsis and keeping fresh.
In the international packing standard residual oxygen index to limit, production index and on the shelves of index also is different, the former is less than 3% commonly, the latter is less than 1%.
2, vacuum packaging vacuum packaging is packed the goods into air tightness after container, the container before sealing process of pumping air into vacuum state, make basic without air sealed container after a packing method.
General commodities, grain processing meat and some easy oxidation of goods can be using vacuum packaging, vacuum packaging not only can avoid or reduce fat oxidation, and inhibit the growth of certain fungi and bacteria.
In carries on the heating sterilization at the same time, because the container internal gas has been ruled out, thus speeding up the heat conduction.
Improve the efficiency of the high temperature sterilization, also avoid the heating sterilization, packaging container cracking due to the expansion of gases.
3, packaging contraction packaging is to use shrink film wrapping package items (
Or the inner packing)
And then to appropriate heat treatment of thin film, shrink film and close to the goods,
Or the inner packing)
Methods of packaging technology.
Shrink film is a kind of specially polyethylene film of the drawing and cooling process, due to shrinkage film produced when directional tensile residual stress, the stress under a certain heat will be eliminated, so that the transverse and longitudinal contraction, at the same time increase the thickness of the film, shrinkage rate is 30% ~ 70%, usually reach maximum contraction force in the cooling phase, and can keep for a long time.
4, stretch packaging stretch packaging is adopted in the seventy s a new packaging technology, it is developed by shrink wrap, stretch packaging relied on mechanical devices at room temperature is elastic thin film around the package drawing, tightly wrapped, and in the end to sealing a packing method.
Due to the stretch packaging need not be heated, so the consumption of energy is only about one over twenty of the contraction packaging.
Stretch packaging can strapping singletons, also can be used for the collection of pallet packaging such as packaging.
5, DNA packaging deoxidized packing is following vacuum packing and filling method of a new type of oxygen packaging.
DNA packaging is in sealed container, can use with oxygen deoxidizer in one of the chemical reaction, so as to remove oxygen in the packaging container, in order to achieve the purpose of protection of built-in objects.
DNA packaging method is suitable for some particularly sensitive to oxygen, is used in those even trace oxygen can also lead to bad quality of food packaging.
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