Plastic cover is a common package currently bottles, cans, barrels packaging, especially applications in the beverage, chemical and pharmaceutical sectors more widely, depending on its use can be divided into air-permeable plastic cover and airtight plastic cover.
Plastic cover is generally a polyolefin as the main raw material, through injection molding, hot press molding process. Plastic Cap which called for consumers to open, and the need to avoid because of poor sealing performance and cause leakage problems. How reasonable cap on sealing performance is controlled production units online or offline detection focus.
Plastic cover performance characteristics
1.The top of the inner wall of the plastic cover is generally provided on an annular ring leak; also ordinary plastic lid to fit within the cap, they do not leak-proof design ring;
2.The lower end of the plastic cover by pulling a theft ring stiffener connection;
3.While the anti-theft ring on the inner wall of a uniform distribution of several pieces of sheet tension swirling wing;
Through this design with a plastic lid firmly sealed, leak-proof and anti-theft performance, safe and convenient to use, can effectively prevent the liquid in the container from outside contamination, to ensure that all liquid packaging meet national safety standards and so on.
Plastic cover caps detection
So how reasonable Plastic Lids sealing performance control unit is online or offline production focus detection for plastic anti-theft caps, because you want to test the seal level, so use positive pressure to seal tester, but the market's positive seal tester is sealed to the inner vessel directly into the compressed air, so it is inevitable explosion occurred when the container is flawed, according to expert estimates, a 2.5-liter bottle of Coke, if the explosion occurred at 1.2MPa, it is quite devastating 100-150 grams of explosives.
Standard Test Method
National Standard GB / T17876-1999 specifically detected a problem with this plastic anti-theft caps were clearly defined, open the bottle cap torque force, thermal stability, resistance to performance drop, leakage and sealing performance.
Wherein the sealing performance and the cap on, tightening torque of the assessment is an effective way plastic anti-theft caps sealing resolved. Depending on the purpose of the cap, and the cap on non-gas measuring method gas cap have different requirements.
Closures (excluding gas cap) caps need to cut anti-theft ring (bar) for not less than the rated torque 1.2NM sealed with a seal tester  test, pressurized to 200kPa, underwater holding pressure for 1 minute, observe whether the leak or release; venting cap (gas cap) is pressurized to 690kPa, keep up the pressure in the water for 1 minute, observe whether the leak, then the pressure is increased to 1207kPa, keep up the pressure for 1 minute, observation plastic cover is tripped.