Plastic Pilferproof Closure’s Airproof Character Testing
22 August 2008
Plastic pilferproof closure is the most commonly used encapsulation, especially in the field of beverage and drink. According to its usage, we could divide it into with and without pressure closures. Plastic pilferproof closures are mainly produced with polyolefin by injection moulding, hot pressing and other techniques. Plastic pilferproof closures should be easy to open by consumers and can avoid leakage due to bad airproof character. To manufacturers, the reasonable airproof character control for plastic pilferproof closure is the key-testing item on-line and off-line.
Standard GB/T 17876-1999 stipulate some rules for plastic pilferproof closure test specifically, such as opening torque, thermal stabilization, fallen resistance and airproof character etc. The assessment of airproof character and torque is an effective way to estimate the performance of plastic pilferproof closure. According to different uses of pilferproof closure, there are different rules to test the closures with and without pressure. For closures without pressure, cut off the pilferproof loop firstly, and then using more than 1.2NW rating torque to seal it. Test it using Leak and Seal Strength Tester, pressurizing it to 200kPa,maintaining the pressure in one minute underwater, and observing whether it leaks or disengages. For the closure with pressure, pressurize it to 690 KP, maintain the pressure in one minute underwater, observe whether it leaks or not, then increase the gas pressure to 1207 KPa, keeping the pressure in one minute to observe whether the pilferproof closure disengages.
The LSSD-01 leak and seal strength detector is supplied by Labthink as an example to give the introduction. “LSSD-01 Leak and Seal Strength Detector” can test airproof character for each kind of standard plastic pilferproof closure with and without pressure closures, that the capsules with the diameter of thread are 28mm and 38mm. Meanwhile, it could also give the analysis of the index between torque and airproof, capsule disengaging strength, stress force of materials and the data of airproof, press resistance, burst resistance for the whole bottles. It equipped with a fixture for plastic pilferproof closure test. Install and seal the plastic pilferproof bottle cap with professional testing accessories and put it into the transparent jar. Start the test after setting the parameters of test pressure, leakage rate, test conditions and etc. Testing pressure, quantity of leakage etc could be showed on LCD directly as well as by observing the bubbles in the translucent testing chamber.
The airproof character of plastic pilferproof closure is the main factors to affect packaging leaking and degeneration of products. The reasonable control could ensure the good opening performance and avoid the leakage. We hope this measurement introduction of leak and airproof performance test for plastic antitheft bottle caps will give you some helps for your production and quality control of plastic pilferproof closure.
