This ASTM test method describes the procedure for testing the torque retention of continuous thread closures. Closures are fitted to containers at the application torque determined on the basis of the desired removal torque range. 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.
A calibrated torque instrument capable of recording clockwise and counter-clockwise torque. The instrument should have a means of securely holding the container without distortion.
1. 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.
2. Use the torque testing system to set the application torque at the application torque determined on the basis of the desired removal torque range. Record the application torque.
3. For static evaluation, measure the removal torque of one group immediately. Store the other remaining groups for the required intervals, temperatures and humidity before measuring the removal torque. Record the removal torque, the storage conditions, the interval before measurement.
4. For dynamic testing, use the torque testing system to set the application torque recommended at the application torque determined on the basis of the desired removal torque range. Record the application torque.
5. Measure the removal torque of one group immediately, Record the removal torque.
6. 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 storage conditions, and interval before measurement.
• Report the torque equipment used and its calibration status
• Report all information to identify the containers and closures employed.
• Report the application torque and mean value for each test condition variable
• Report the removal torque and mean value for each test condition variable
Tornado manual digital torque tester
Alternatively, a motorised torque measuring system may be used. This increases repeatability of testing as the application and removal torques are applied consistently. The system can also record and store all the results and can create reports:
Vortex-xt touch-screen controlled torque test system.
Please refer to the latest official ASTM test method D 2063-91 standard for more detailed information. This overview is intended to provide a basic understanding of the test procedure and suitable equipment to meet the standard
