Packaging for food , maintaining the original taste and freshness for the best, but for the present to do this , and most products are achieved by freezing it, in order not by freezing is necessary from the proceed on the packaging , the current in the packaging machinery industry , and some equipment has been done at that point , it adopted advanced production technology and a gas-permeable material combines manufacturing outsourcing will breathe packaging.
Want to make the product packaging will exhale , we must make the first oxygen , food packaging, built- in desiccant , preservatives or oxygen scavenger , fruit and vegetables can be removed so that the release of water vapor and other unfavorable storage preservation of ethylene gas substances. This is mainly through the gas bag outside the preservative penetration or bag , desiccant or deoxidizer revealed , hair life science reactions or a combination of physical adsorption effect to be achieved. To achieve this effect will make the bag has a certain permeability or to prevent leakage of bag material effect. In between, the permeability of the paper bag is an important physical parameters , may decide to use different wrapping machine uses, such packaging materials in the packaging machinery industry is rare, is a kind of new things.
With the idea , followed by that specific practical work , then they would pick up from the packaging material , for this can be controlled atmosphere packaging, necessary according to the actual product characteristics, package material permeability reasonable choice . Typically, for the MAP gases are oxygen, nitrogen, carbon dioxide mixed gas , or oxygen, carbon dioxide mixed gas , for which , in the choice of packaging material when the oxygen permeability of the material , the carbon dioxide through the resistance, nitrogen permeability for accurate testing , not favoritism for various gases , to be allocated proportionally . If you assign unreasonable packaging materials into packaging machinery production line will cause serious consequences.
Current test permeability testing in two ways: equal pressure method and arithmetic method . Equal pressure method than a single detection target , only check the permeability of oxygen and carbon dioxide , nitrogen gas permeability can not be detected , and the arithmetic method is somewhat different , it is not selected test gas , in addition to oxygen and carbon dioxide can outside the detection of nitrogen gas , and the test low cost can be realized since the temperature of the test environment . Therefore, in the packaging machinery industry , where there are engaged in modified atmosphere packaging have adopted this approach .