I checked the actual test data of the bottle cap opening torque in my hands over the years, and it is indeed constantly decreasing. Whether it is the customer’s requirements or our requirements for the bottle cap designer/mold manufacturer when the bottle cap is updated. But it cannot be reduced without limit. Reducing it to a certain level will bring fatal risks. Let’s talk about it in detail below.
2.1 You cannot blindly satisfy the convenience of opening at the expense of sealing function
The sealing of the single-piece cap mainly relies on the interference fit between the inner plug and the inside of the bottle mouth. The greater the interference fit, the better the sealing effect. Of course, the resistance when opening is the greater the opening torque. To reduce the opening torque, it is necessary to reduce this interference fit, but what follows is that the sealing effect is not so good, and the product has quality risks!
The friction between the bottle cap thread and the bottle mouth thread cannot be reduced indefinitely. First of all, in that case, the sealing effect of the double-piece cover cannot be guaranteed. Secondly, the product will be affected by external adverse effects such as vibration and temperature changes during transportation and storage. If the friction is insufficient, the bottle cap will loosen or even slide in the direction of opening, which puts the product quality at risk!