The most popular packaging materials that hinder f

Packaging materials that hinder food safety in the market not long ago, the Teflon incident caused a great uproar in China. At present, there is no final conclusion about the outcome. However, through this incident, we should not only pay attention to the safety of Teflon materials, but also the safety of food packaging

whether the nonstick pot produced with Teflon paint will cause cancer when used improperly has been debated for a long time. One side of the debate is DuPont, the producer of Teflon, while the other side is difficult to find in China. If we insist on saying who is the opponent of the debate, we can only say that it is the media and the public. Regardless of the outcome of the debate, this debate is a big blow to domestic non stick pot manufacturers. The food packaging safety problems caused by this incident should also attract the attention of industry insiders

Teflon is a kind of plastic, which is the general name of all fluorocarbon resins developed by DuPont company of the United States. The main raw material is polytetrafluoroethylene. In the process of Teflon processing, various additives should be added to obtain better processability and usability. Ammonium perfluorooctanoate (PFOA) is an additive used in the processing of Teflon, which is still blindly controlled if the control effect is not clear. This additive is used as a surfactant. It has been proved that ammonium perfluorooctanoate (PFOA) has carcinogenic effect, but as an additive for the production of Teflon, there is no conclusion whether it will produce conversion and reduction after use

various additives should be added to plastics in the processing process. Some of these additives are non-toxic, some are toxic, and some are toxic only after a variety of additives are combined. Some additives are relatively stable and some are more active. When plastic decomposes at high temperature, some additives may be 3 Fasten the inclined sample with the fastening screw with the stirring piece on the main shaft to release harmful components and cause harm to human body. At present, the dispute over Teflon is whether ammonium perfluorooctanoate (OA under the trend of PF consumption upgrading) will be released when the temperature exceeds 250 ℃, affecting people's safety. Generally speaking, the plastic raw materials used for direct food packaging are safe, and the chemical stability, heat resistance and self lubrication at room temperature can meet the safety requirements. However, whether the food packaging materials at the time of melting are still safe should be tested and determined by authoritative departments

the problem of Teflon was first caused by the relevant authorities in the United States, which shows the importance they attach to public safety. However, in China, we do not attach great importance to similar safety problems caused by this phenomenon. The current liquid flexible packaging can explain this problem. At present, the packaging bags of liquid flexible packaging products need to undergo several processes, such as plastic melting into single film, printing, compounding into packaging film, bag making and filling, and each process has safety problems. In the melting film making process, some small factories often add waste plastic films to reduce costs. This kind of film is easy to be identified by color, so some manufacturers add some additives to change the color and feel of the film. These old films and additives form the first step safety problem of packaging film; To print words and patterns on plastic film, in order to make it easy to color and look bright, it is often necessary to add various additives, some of which are toxic, and the better the effect, the more toxic the additives are, which forms the second step safety problem of packaging film; In the process of compounding two or more kinds of plastic single films together, we also need to use various adhesives and additives. Most of these adhesives and additives are chemical products, and the amount of use is strictly limited. However, in small factories with imperfect technology and equipment, it is difficult to control the amount of these products, which will lead to pollution and safety problems. This is the third step safety problem of packaging film

the biggest safety problem of liquid packaging films lies in the fourth step, that is, these films are in direct contact with liquid in the molten state, causing serious pollution and quality safety problems of liquid food. Taking the soft packed soy sauce as an example, can the melting cut-off soft packed soy sauce cause safety problems? Let's look at the packaging process of soft packed soy sauce. Soft packed soy sauce uses low-cost polyethylene as the packaging bag, and uses printed and laminated roll of polyethylene film to directly make bags, fill, seal and cut. This cutting adopts eagerness, that is, to pull the molten plastic under the action of gravity, that is, to melt the cylindrical bag filled with soy sauce from the middle, and form the sealing of the upper and lower bags by pressure and soy sauce cooling. In the process of melting and heating, not only the plastic bag reaches the melting temperature, but also the soy sauce is locally heated and even vaporized at the same time. The molten plastic and the heated soy sauce are intertwined to form the seal of the bagged soy sauce. Now it is hard to say that this packaging method must be harmful to human body, but it can be said that anyone who understands this packaging process will be afraid of this product

the temperature of heat sealing and cutting is also different according to the material and thickness of the packaging film. For single film packaging bags, the heating temperature is relatively low, about 120 ℃; For the packaging bag of composite film, the heating temperature is relatively high, about 140 ℃; For some plastics, these temperatures cannot be sealed at all, and satisfactory sealing effect can be obtained only when the temperature of the film reaches about 200 ℃. Under the action of these temperatures, in addition to the melting of the packaging film, the soy sauce at the melting point of the packaging film is also completely vaporized and carbonized. The higher the temperature is, the more serious the carbonization is, which can be seen from the carbon collection on the heating sealing tool of the packaging machine. Flexible packaging soy sauce has a large market in China. Most of the packaging materials used are polyethylene, from medical equipment to auto parts. When processing polyethylene, we also need to add a variety of additives. Whether these additives will volatilize harmful gases when polyethylene plastic melts should attract our attention. In fact, this problem is the same as the Teflon problem. There are many similar examples, such as some soft packaged milk, beverages, etc., using the same packaging machine and roughly the same packaging film, which have the hazard of additives after melting. The degree of harm depends on the detection of authoritative departments

Teflon is waiting for a ruling, which is also a problem under the specified service temperature; And polyethylene plastic has been used in the molten state. Should it also attract the attention of relevant departments

there is nothing trivial about food safety. Judging from the Teflon incident, there are still many problems in domestic food packaging safety. For example, hawkers selling breakfast often use plastic bags to pack hot fried dough sticks, which often results in the melting of plastic bags; Another example is the problem of using plastic bags to pack rice on bowls. Although it may prevent bacterial pollution, it is not enough to prevent the additive pollution of the plastic bags themselves

there are many similar examples. It is not that these problems cannot be solved or are difficult to solve, but that we pay attention to them. First, we should strengthen scientific research and draw scientific conclusions. Second, we should speed up the implementation of the conclusions