30-50 μ m thick food grade acid resistant aluminum foil film must be selected. It is recommended to use modified polypropylene or special PE formula for the heat sealing adhesive layer to ensure that it can resist the acid environment and salt corrosion of Fermented bean curd. All materials must comply with the GB 4806 standard for food contact materials to ensure food safety. 

The control of process parameters is particularly crucial. The sealing temperature should be strictly controlled between 150-170 ℃, the pressure should be maintained at 0.3-0.4MPa, and the heat sealing time should be 1.5-2 seconds. For glass bottle packaging, the pressure needs to be reduced by 20% to avoid bottle mouth damage. Vacuum degassing treatment before packaging is essential. It is recommended to control the residual oxygen level below 1% and add food grade oxygen absorbers to further reduce the residual oxygen level to below 0.5%. 

The quality verification process needs to focus on three tests: the 85 ℃ water bath test should have no leakage after 30 minutes, the sealing strength should reach 3N/15mm or more, and the accelerated aging test should be conducted for 90 days in an environment of 40 ℃ and 75% relative humidity. These tests can effectively ensure the long-term stability of the sealing film in Fermented bean curd, a special food package. 

During storage and transportation, special attention should be paid to environmental control. Avoid direct sunlight to prevent oxidation of the aluminum layer, control the environmental humidity below 65%, and stack no more than 5 layers in height. It is recommended to conduct small batch testing before production, with a focus on observing whether there are bulges within 7 days, whether there are corrosion spots on the aluminum layer after 30 days, and whether there are residual adhesive layers when opening the lid. 

In view of the gas production characteristics of Fermented bean curd fermentation, it is recommended to give priority to the aluminum foil composite membrane with micro permeability function, and control the carbon dioxide transmittance within the range of 5-15cm ³/m ² · day. Pre exhaust packaging technology can also be used to fully exhaust the gas before sealing.   

Leadtra Packaging is a professional manufacturer and global service provider of aluminum foil sealing film, providing one-stop services for sealing film, sealing gasket products and solutions. We are stationed in the factory for debugging, solving your sealing problems, and ensuring your production cycle. If you are interested in or have any questions about us, please feel free to call us for consultation.