Food must be sterilized when it is packaged. Different sterilization methods have different requirements for packaging materials. The commonly used sterilization method is thermal sterilization. For low temperature, high temperature and ultra high temperature sterilization.
Low-temperature sterilization (also known as pasteurization): sterilization conditions 61-63 ° C / 30min or 72-75 ° C / 15-20min, this sterilization method can kill most pathogenic bacteria, if stored with other Means such as freezing, refrigeration, and deoxidation can meet the requirements of achieving a certain shelf life.
High-temperature short-term sterilization method: The sterilization conditions are 85-90 ℃ / 20-30min or 95 ℃ / 5-15min, which can mainly kill yeast, mold, lactic acid bacteria, etc.
Ultra-high temperature instant sterilization method: 121-125 ℃ / 15-30min.
The first two sterilization methods are commonly known as “boiled water”, which is a relatively simple sterilization method. It has the characteristics of stable sterilization effect, simple operation, and small equipment investment. The structure of conventional boiling-resistant packaging includes PET / AL / PA / PE, PET / AL / PE, PET / CPP, PET / PE, PA / CPP, PA / PE, OPP / VMPET / PE, etc. The basic requirement of the material is that the thermal shrinkage of each substrate under boiling conditions should be the same or similar.
The ultra-high temperature sterilization method is currently the most widely used sterilization method. It uses a high-pressure steam sterilizer to sterilize, and uses a high-pressure saturation and water vapor to heat the closed container to obtain a higher temperature, which usually reaches 121.3 ℃, can kill all microorganisms including bacterial spores, the conventional retort-resistant packaging structure is PET / AL / PA / RCPP, PET / AL / RCPP, PET / RCPP, PA / RCPP, PET / RCPE, PA / RCPE, etc.