Grasping the Concept of Torque in Closure Uses
Grasping the Concept of Torque in Closure Uses
Torque is the rotational force exerted when putting on or taking off caps from containers. It is essential to apply the correct amount of torque when sealing a container to achieve an effective seal. The objective is to uniformly apply the torque around the closure, which helps avoid leaks and maintains the integrity of the seal.
Many people mistakenly believe that tightening a cap more will prevent leaks. In reality, over-tightening can make leaks more probable. Excessive force may create uneven pressure on the cap, compromising the seal. On the other hand, not applying enough pressure can leave the cap loose or inadequately sealed, which can also lead to leaks.
Applying the correct torque is crucial for effectively sealing and loosening closures. The table provided below details the suggested torque levels based on different cap sizes and materials. These figures indicate the minimum torque necessary to achieve a reliable seal and facilitate removal. Typically, a good rule of thumb is to use torque that is roughly 50% of the cap’s diameter, measured in inches per pound.
Key Takeaways:
- Seal failure can result from over-tightening the cap or closure.
- A cap that is not properly tightened can cause leaks.
- The torque value recommended varies depending on the cap type and material (e.g. glass or plastic).
- Test your closure system to get the best results. Packaging variables can have an impact on the seal's performance. Torque testers are the most accurate way to measure torque.
Recommended Torque for Cap Application and Removal
Refer to the chart below, which illustrates the recommended torque for both application and removal based on various cap sizes and materials. Adhering to these values will guarantee optimal sealing and facilitate easier removal.
| Cap Size (mm) | Phenolic/Urea Cap on Glass | Phenolic/Urea Cap on Plastic | PP / PE Cap on Glass | PP / PE Cap on Plastic | ||||
|---|---|---|---|---|---|---|---|---|
| Application Torque | Removal Torque | Application Torque | Removal Torque | Application Torque | Removal Torque | Application Torque | Removal Torque | |
| 18 | 9 | 5 | 7 | 4 | 13 | 8 | 9 | 5 |
| 20 | 10 | 5 | 8 | 4 | 15 | 9 | 10 | 5 |
| 22 | 11 | 6 | 9 | 5 | 17 | 10 | 11 | 6 |
| 24 | 12 | 6 | 10 | 5 | 18 | 11 | 12 | 6 |
| 28 | 14 | 7 | 12 | 6 | 21 | 12 | 14 | 7 |
| 33 | 18 | 9 | 15 | 7 | 24 | 14 | 17 | 8 |
| 38 | 20 | 10 | 17 | 7 | 29 | 17 | 19 | 9 |
| 43 | 22 | 11 | 18 | 9 | 33 | 20 | 22 | 11 |
| 48 | 24 | 14 | 20 | 10 | 26 | 22 | 24 | 12 |
Ensuring that containers are sealed correctly requires the appropriate torque to safeguard product quality and avoid leaks. It’s important to apply torque with precision and assess your packaging system to confirm a secure seal. Utilizing a torque tester will provide you with the most precise measurements for both sealing and opening.