ASTM D7860-14 | Mecmesin

Significance and Use

5.1 This test method allows for the measurement of the torque retention properties of container/continuous thread closure systems of various designs, materials, and manufacture, and is suitable for package development and engineering evaluation.

5.2 Each test method can be used for the evaluation of non child resistant container/continuous thread closure systems under controlled conditions such as when the application torque is known and the applied downward force to the closure is zero or for Type I, style “A” push down and turn child resistant container/continuous thread closure systems under controlled conditions such as when the application torque and the applied downward force to the closure is known.

5.3 This test method measures torque retention properties of container/continuous thread closure systems with the use of an automated transducer based torque meter operating at a known rotational velocity (rpm) or known torque ramp.

5.4 This test method is intended for measurement of dry torque only.

1.1 These test methods evaluate the torque retention of continuous thread closures on containers with matching finishes, for predetermined environmental conditions over time. Methods are defined for both Type I, style “A” push down and turn Type II2 child resistant and non child resistant type closures.

1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard. NOTE 1: The SI unit system is the recommended system.

1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Method

Test summary

This ASTM test method describes the procedure for testing the torque retention of continuous thread closures. The tests can be applied to child-resistant or non child-resistant closures. In all cases, closures are fitted to containers at the application torque recommended by the manufacturer. The test may be “static” where groups of closed containers are stored for varying periods of time, temperature and humidity before the removal torque is measured. The specified intervals are; immediately, 24h, 48h, 7 days, 14 days and 28 days.

Alternatively, the test can be “dynamic”, where groups of closed containers can be subjected to conditioning and distribution cycles before the removal torque is measured.

Test apparatus

A calibrated motor driven torque system capable of recording clockwise and counter-clockwise torque with a programmable, fixed rotational velocity. Where applicable, a means of applying a static downward force to activate the child resistant mechanism is required. The instrument should have a means of securely holding the container without distortion. A special cap mandrel may be used to hold the closure to facilitate application and removal without distorting the closure.

A torque calibration verification device. This is used to verify clockwise and counter-clockwise calibration of the torque measuring system prior to testing.

Preparation

The torque measuring system should be calibrated in accordance with recognised traceable international standards. The calibration must be verified by using the torque calibration verification device by measuring both the application and removal torque five times before testing begins.

Test method

Select sufficient quantities of new containers and closures to allow for control groups and at least 10 specimens for each torque measurement point per test variable. Also consider if a sterilization cycle is to be included.

If required, condition the specimens in accordance with Specification E171 and Practice D4332.

Fill the containers with the specified volume or weight of product or other materials that yields a similar weight and thermal characteristics.

Use the motorised torque testing system to set the application torque recommended by the container manufacturer or recognised industry Institution. Where required, simultaneously apply sufficient downward force to activate the child resistant mechanism. Record the rotational speed, the application torque and the downward force applied.

For static evaluation, measure the removal torque of one group immediately, again providing a constant downward force in the case of child resistant closures.

Store the other remaining groups for the required intervals, temperatures and humidity before measuring the removal torque. Record the removal torque, the rotational speed, the storage conditions, the interval and downward force if applicable.

For dynamic testing, use the motorised torque testing system to set the application torque recommended by the container manufacturer or recognised industry Institution. Where required, simultaneously apply sufficient downward force to activate the child resistant mechanism. Record the rotational speed, the application torque and the downward force applied.

Measure the removal torque of one group immediately, again providing a constant downward force in the case of child resistant closures. Record the removal torque, the rotational speed, and downward force if applicable.

Subject the remaining specimens to the selected distribution cycle, and then measure the removal torque as before. If information about long term storage is also required, then further specimens can be subjected to the required storage condition before removal torque measurements are made. . Record the removal torque, the rotational speed, the storage conditions, and interval and downward force if applicable.