The value of the cap locking and opening torque of bottled cosmetics and other container products is one of the process parameters that the production unit focuses on offline or online control. Whether the torque value is appropriate has a great influence on the intermediate transportation of the product and the final consumption.

People apply cosmetics to human skin or facial features through methods such as smearing, spraying, and spraying to achieve the effects of cleaning, beautification, care, maintenance, and modification. According to the type, it can be divided into liquid, lotion, cream, powder, block, and oil. Liquid and emulsion cosmetics packaging are roughly divided into bottles, tubes, and bags. Bottled cosmetics are divided into two types: plastic bottles and glass bottles. The bottle mouth is divided into rotary, push-pull and push-type. Among them, rotary bottle The mouth is often packaged with a screw cap, which requires manual rotation and unscrewing before use. If the screw cap is too tight, it is not convenient for consumers to open it. If the screw cap is loose, the quality problem of bottle mouth leakage may occur.

How to solve the problems of easy opening and good sealing on the basis that the opening force required by the screw cap is within the acceptable range of the consumer for similar screw cap bottled cosmetics needs to be verified by effective monitoring methods.

1. Current status
At present, domestic testing of the opening torque performance of bottle caps mainly refers to the method of "opening torque test" in GB/T 17876-2010 "Plastic Anti-theft Bottle Caps for Packaging Containers". This standard is suitable for use with polyolefin as the main raw material. For bottle caps formed by pressing or other processes, the cap cannot be restored to its original packaging form after being sealed and then opened.

2. Sample
A certain brand of lotion in a plastic bottle with a plastic anti-theft bottle cap.

3. Testing equipment

3.1 Test principle
It is equipped with a torsion angle phase difference sensor and a strain bridge detection method is used to monitor the electrical signal of the elastic shaft torsion during the sample test, so as to test the opening torque or locking value of the bottle cap.

3.2 Scope of application
(1) This equipment is professionally suitable for testing the torque value of locking and opening the bottle caps of cosmetics, food and medicine (threaded connection) in bottled packaging and tube packaging. Such as hand cream, beverage bottles, medicine bottles, etc. In addition, it can be extended to test the torque value of the bottle cap, nut and bolt of the thermos and thermos (threaded connection).

(2) The equipment meets many national and international standards: GB/T 17876, ASTM D2063, ASTM D3198, ASTM D3474, BB/T 0025, BB/T 0034.

3.3 Equipment parameters
l Torque specifications are 20 Nm, 40 Nm, 50 Nm, accuracy is level 1, and the system resolution is 0.001 Nm.
l The clamping range is 5 mm ~ 170 mm (diameter).
l Provide dual test modes of opening force and locking force.
l The measured peak value is automatically maintained to ensure that the test result is accurately recorded.
l Intelligent configuration such as overload protection, automatic reset, and fault prompts to ensure the safety of users' operations.
l The system adopts microcomputer control, with LCD liquid crystal display screen and PVC operation panel, which is convenient for users to quickly and intuitively check the test data and results.
l Support LystemTM laboratory data sharing system, unified management of test reports and test results.

4. Test process
(1) In a standard laboratory environment, place the adjusted cosmetic bottle sample on the instrument fixture and clamp it.
(2) Set the instrument mode to "Turn on torque" and click to start the test.
(3) Put your hand on the bottle cap and unscrew the bottle cap. At this time, the instrument automatically detects the opening torque value.
(4) Follow the above steps to test the remaining 2 samples in sequence.

5. Test results
The tested plastic bottle packaging cosmetic bottle cap opening torque values ​​are 0.405 Nm, 0.421 Nm, 0.417 Nm, respectively.

6. Conclusion
The value of the cap locking and opening torque of bottled packaging products, nozzle packaging products, and tube packaging products is one of the process parameters that the production unit focuses on offline or online control.