What is the test standard for the sealing performance of F-type metal cans?

1. Pressurization test (arbitration method)
Purpose: To detect the sealing performance of canned food metal containers.
Method:
Wash the container and dry it upside down at 50°C for 2 hours.
Immerse the container in the water tank of the pressurized leak detector, slowly pressurize it to 0.26MPa and keep it for 2 minutes, and observe whether there are bubbles in the can body, especially at the curling weld.
If bubbles are continuously generated in the same part, it is judged as a leak, and the leaking part is marked.
For pasteurized samples, the test pressure can be 0.068MPa.
2. Sealant performance test
Water resistance of sealant:
Put the sample cover in a glass container filled with water, and the water covers the sample cover by about 50mm, then put the glass container in a pressure cooker, boil it at 100°C for 20 minutes, take out the sample cover, and observe the performance of the sealant.
After boiling, the sealant should not curl, be sticky, have odor, fall off, etc.
Moisture content of sealant: The moisture content of sealant should not exceed 5%.
3. Internal and external coating performance test
Inner coating integrity:
Simulate sterilization of empty cans at 121°C for 30 minutes.
Add 2% (mass fraction) sodium sulfate solution into the can, and the liquid level is 3mm from the can mouth.
Use a 6.3V coating integrity tester, connect the can body to the positive pole, insert a stainless steel rod to the negative pole, and read the inner coating defect current value at the 4th second.
Internal and external coating curing test:
Put the can body or cover as a whole into a high-pressure sterilizer, add distilled water to immerse the sample and seal it.
Determine the sterilization temperature and time according to the sterilization process of the contents.
Take it out after the test, cool it in cold water, and visually inspect it after drying.
Acid resistance, sulfur resistance, and salt resistance:
Use 2% citric acid solution, L-cysteine hydrochloride mixed solution, and 3% sodium chloride solution for testing respectively.
Determine the heating temperature and time according to the sterilization process of the contents.
After the test, take it out and cool it in cold water. Open the can and rinse it with clean water. After drying, visually inspect it.
4. Other testing methods
Metal can sealing test device: A patented device pierces the bottom of the sample can with a puncture head and evacuates the seal, then pressurizes the inside of the can to test the sealing of the cover.
Periodic inspection and intermediate inspection: For tank vehicles, the periodic inspection is conducted every 5 or 8 years, and the intermediate inspection is conducted every 2.5 or 4 years, including leakage test and hydraulic test.