Test Method for Reverse Ratchet Torque of Spinning Cover

In the AST M standard catalog, the test standard for reverse ratchet torque of pressure spinning covers is ASTM D 3472-1997 (2002) 'Test Method for Reverse Ratchet Torque of Type IA Child Resistent Closures'. This test method is mainly used for torque detection of child safety covers that rotate counterclockwise. The experimental equipment is a torque detector that detects the torque of the child safety cover rotating counterclockwise (i.e. reverse ratchet torque) without applying force in the vertical direction. The reverse ratchet torque is a torque in the opening direction of a bottle cap, and it is also an important torque for pressing and rotating the cap. This torque should not be lower than a certain value, otherwise the bottle cap will easily loosen. In general, the reverse ratchet torque is less than 10lbf · in (1.1N · m), so the detection range of the torque detector only needs to be 0-25lbf · in (0-2.8N · m) or 0-10lbf · in (0-1.1N · m). The test sample is an unused threaded screw cap with an inner cover structure, and its repeatability requires attention to the effects of time, temperature, and humidity conditions on torque measurement.

Detection steps

Place the packaging container on the torque tester and rotate the outer cover of the child safety cover counterclockwise three or more times; Rotate all samples smoothly and slowly at the same speed; Do not generate force in the vertical direction and avoid excessive compression of the outer cover; The maximum torque read on the torque tester is the reverse ratchet torque value.

note

It should be noted that the thread structure, inner and outer cover materials, and coating of the inner cover of the pressure spinning cover

The layer material, container material, and structure all have an impact on the test results. So in the final testing report, all the above conditions and factors must be clearly described one by one.