Why do we insist on leakage testing with hot black coffee above 90℃?

Disposable paper cups are widely used for hot and cold beverages such as coffee, tea, soda and shakes. Hot beverages, such as coffee, tea, and hot chocolate, are often served at temperatures above 90℃, and if a paper cup is not able to withstand this temperatures, it may leak or even break, causing potential harm to the user . In addition to safety concerns, leakage will ruin the customers experience and can also cause a loss in cost ,time and product quality .

Therefore ,leakage testing is a crucial process in the manufacturing of paper cups, as it ensures that the cups can hold liquid without any leakage. The most common methods for leakage testing include water bath test, vacuum test, air pressure test and dye penetration test.

Our company use hot black coffee above 90℃ to test the leaking of the paper cups  .

There are at least three advantages to doing this:

1. Hot black coffee is more permeable than hot water, and the problem cannot be fully discovered with hot water.

2. If there is a leak, the black color can help us find it immediately.

3. it simulates the real-world conditions under which the paper cup will be used.

4.Hot liquids tend to expand and contract more than cold liquids, a phenomenon known as thermal expansion. This can cause additional stress on the paper cup’s structure, making it mbore vulnerable to leaks and other defects.

We use this more costly but more effective method of ensuring quality and provide high quality paper cups .Be due to this essential process is a key step towards ensuring that the end-user has an enjoyable and safe experience with our products.