The causes of food vacuum bag smell

Nearly period of time, many people ask why food vacuum bags always have peculiar smell, because be packaged foods, so this problem is very serious. Underneath, small make up for all detailed analyze the causes of food vacuum bag smell, hope will be helpful to you. 我。 Odor source film, all kinds of printing ink, adhesives, organic solvent will bring all sorts of peculiar smell. There are many different kinds of packaging materials produced by the peculiar smell and complex, there are sweet, sour, sulfur, medicine, jiao, wax, oil, ink, soap, tar, solvents and so on, bad breath is not only caused by a substance, and it is caused by a mixture of substances. Describe the smell is particularly difficult, because small changes in the mix ingredients can lead to the differences of odour. Thin film in the odor comes mainly from the two parts: resin itself various additives and low molecular substances; The peculiar smell in the process of flexible packaging processing. 2 Source analysis of the heat sealing layer of PE film is commonly used in composite bags and CPP is easy to produce peculiar smell. Detection: prepare 5 1 l wide mouth bottle, 0. 1 ㎡ BOPP, PE, CPP, PET film and the finished composite membrane, dry in 60 ℃ oven for 30 minutes, remove the cooling 30 minutes, and judgment. 2. Flexible packaging peculiar smell in the process of 1) Thermal decomposition in polyethylene decomposition odor material, can be roughly divided into aliphatic hydrocarbon and aromatic hydrocarbon. According to research, thermal decomposition into 3 - 28 carbon saturated or unsaturated hydrocarbons which produce 3 - short branched chain Six carbon compounds, greater influence on its content. Because of low volatility and low polarity, the material can be stored in membrane medium and long term. 2) Odor when plastic caused by thermal oxidation under high temperature and high shear processing, in addition to the thermal decomposition, after extrusion die, it will be hot with oxygen in the air oxidation reaction, which produce peculiar smell. In order to make the ink or adhesive has better viscosity, need to deal with different plastic film by corona or flame. Due to oxidation, offset surface tension, and in the subsequent will encounter in the process of the coating used in producing a set of material ( Alcohol, aldehyde, ketone and carboxyl) 。 If increase the processing strength, not only increases the surface tension, and polymer degradation degree will increase, resulting in a volatile small molecules ( Aldehydes and ketones) These volatile aldehydes and ketones, produce peculiar smell. 3) Heat sealing of smell when composite membrane heating at high temperature, material will decompose, additives can be separated, components of ink adhesive will volatilize and decompose, produce peculiar smell. In the process of processing and forming, in order to improve the machinability of products or performance, will join the various additives, types and composition of these additives each are not identical, this is one of the main factors that cause bad breath. For example, plasticizer, heat stabilizer, antioxidant, anti-uv agent, lubricant, opening agent, antistatic agent, antifoggant, etc; In addition, the functional inorganic additives, such as calcium carbonate, kaolin, talc, silica, etc. , as well as a large amount of dispersant, coupling agent, etc. ; In addition, all kinds of organic pigment masterbatch, titanium white masterbatch, etc. , will join in the heating process. Have a lot of volatile substances. If you add pigment can promote the decomposition of the polymer, have serious odor when heat sealing. 4) Printing ink and adhesive residue solvent ink and adhesive residue solvent in composite flexible packaging materials caused by the smell, the main factor causing the smell is the residue solvent ink and adhesive, especially in dry compound, can't completely avoid residual solvents. At present, the international demand for residual solvents is 5 mg / ㎡, benzene can not be detected. The above is the cause of food vacuum bag smell is analyzed, everyone know? Vacuum packing bag for food, if you have any other questions, we will ask professional engineers to provide you with advice.