How to distinguish between food packaging bags unqualified?

 Food packaging bags more and more to the environment has brought a lot of problems, unqualified packaging bags will cause environmental pollution, how to distinguish between unqualified, from four aspects to reduce environmental pollution.
  First, look at the appearance
  Qualified food packaging bag appearance is the absence of bubbles, perforation and other defects. And the width, length of the deviation are within a certain range, if more than or there is a defect is the failure of the bag.
  Second, good performance
  Qualified in the use of the process can withstand a certain degree of stretching, the use of the process of rupture is unqualified.
  Third, look at health
  Unqualified can check out heavy metals, debris and other substances that are not conducive to human health, while the residue will also affect the quality of food, such a bag for the human body is often a great harm. Qualified food packaging bags tend to have a certain degree of health, to ensure the quality of food.
  Fourth, look at degradation performance
  According to the type of degradation, can be divided into light, biological, environmental degradation of three types. It can reflect the packaging bag is abandoned after the impact on the environment, good degradation can be in the light and other biological effects of the bag to become debris. This is a qualified food packaging bags must have, unqualified can not be decomposed easy to form pollution.
  The quality of food packaging bags for the environment and food is very important, you can distinguish from the above four aspects of qualified.www.nblinhua.com/