What material is the food vacuum bag?
Food vacuum bag is to maintain the quality of food, so that food will not deteriorate in the process of preservation, circulation and sales, prevent microbial contamination, prevent super chemical and physical changes, and facilitate the preservation and storage of food. Food packaging bags are packages that are in direct contact with food. The correct choice of packaging bag materials directly affects people's health.
So,What material is the food vacuum bag?
The main materials of food vacuum bags are: PVDC (polyvinylidene chloride), PE (polyethylene), PA (nylon), EVOH (ethylene/vinyl alcohol copolymer), aluminized film (aluminum + PE), etc., among which PE (Polyethylene) material is a commonly used material for making food packaging bags.
Food vacuum bag material polyethylene
Polyethylene (PE) is one of the five major synthetic resins. Polyethylene is a typical thermoplastic and is an odorless and tasteless flammable white powder. The molded PE resins are all extruded and granulated waxy granules with milky white appearance. The melting point of polyethylene is 100-130C. Its low temperature resistance is excellent. It can still maintain good mechanical properties at -60 °C, but the operating temperature is 80~110 °C.
Polyethylene has good chemical stability and is resistant to dilute nitric acid, dilute sulfuric acid and any concentration of hydrochloric acid, hydrofluoric acid, phosphoric acid, formic acid, acetic acid, ammonia water, amines, hydrogen peroxide, sodium hydroxide, potassium hydroxide, etc. solution. But it is not resistant to strong oxidative corrosion, such as the mixture of oleum, concentrated nitric acid, chromic acid and sulfuric acid. At room temperature, the above-mentioned solvents will slowly erode polyethylene, while at 90-100 °C, concentrated sulfuric acid and concentrated nitric acid will rapidly erode polyethylene, causing damage or decomposition.
Under the action of the atmosphere, sunlight and oxygen, polyethylene will age, discolor, crack, become brittle or powder, and lose its mechanical properties. At the molding temperature, the degree of melt will decrease due to oxidation, discoloration and streaks will occur, so attention should be paid to the molding process and use process or material selection.