As a common packaging container, the sealing performance of a 1L can directly affects the storage safety of its contents. Scientific testing and targeted optimization are required to ensure quality.
There are three core methods that can be used in the testing phase. One is the negative pressure method, which places a 1L can in a sealed testing chamber, extracts air from the chamber to create a negative pressure environment, and observes whether there are bubbles on the chamber wall. If there are bubbles, it indicates that there is a sealing leak. This method can quickly locate small leakage points. The second method is the pressure attenuation method, which involves filling a 1L tank with compressed air at a set pressure, maintaining it for a period of time, and monitoring the pressure changes. If the pressure drop exceeds the standard range, it is judged that the seal is not qualified and is suitable for testing the overall seal integrity. The third is immersion testing, which involves immersing a sealed 1L tank in water and observing whether there are continuous bubbles rising from the water surface to visually determine the sealing status, which is suitable for preliminary screening.
From the test results, it can be seen that the sealing failure of the 1L tank is mainly caused by three key factors. Firstly, the fitting accuracy between the can mouth and the can lid is insufficient. If the size deviation between the two exceeds 0.1mm, it is easy to form gaps; Secondly, improper selection of sealing strip material can cause the strip to harden and lose its elasticity in low temperature environments, while softening and deformation may occur in high temperature environments; Thirdly, the sealing pressure parameters are unreasonable. If the pressure is too low, it will cause the seal to be loose, and if it is too high, it may damage the structure of the can mouth.
The optimization plan can be promoted from three aspects to address the above issues. Firstly, optimize the machining accuracy of the can mouth and lid, control the dimensional deviation within 0.05mm, and ensure a tight fit. Secondly, according to the usage scenario of the 1L tank, select the appropriate sealing strip. Low temperature resistant silicone rubber is preferred for low-temperature environments, while heat-resistant nitrile rubber is used for high-temperature environments. Finally, the optimal sealing pressure is determined through multiple experiments, generally controlled between 0.3-0.5MPa, and equipped with a pressure monitoring device to monitor pressure changes in real-time during the sealing process, ensuring stable sealing quality.