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Roasted coffee beans (powder) packaging is the most diverse form of coffee packaging. Since coffee beans naturally generate carbon dioxide after roasting, direct packaging can easily cause packaging damage, and prolonged exposure to air will cause aroma loss and lead to oil and aroma in coffee. Oxidation of ingredients causes quality degradation. Therefore, the packaging of coffee beans (powder) is particularly important

Commonly used in the market is composite packaging, which is two or more materials combined through one or more dry composite processes to form a packaging with certain functions. Generally, it can be divided into base layer, functional layer and heat sealing layer. The base layer mainly plays the role of beauty, printing and moisture resistance. Such as BOPP, BOPET, BOPA, MT, KOP, KPET, etc.; the functional layer mainly plays the role of barrier and light protection.

If you've ever kept an eye out for coffee bags in a supermarket or coffee shop, you'll notice that most bags have a small hole or plastic valve near the top. This valve plays an important role in keeping coffee fresh and delicious.

The valve is a one-way vent that allows coffee beans and coffee grounds to slowly release carbon dioxide (CO2) and other volatile gases from the bag without contacting the outside air, also known as a fresh-keeping valve valve, aroma valve or coffee valve.

Many chemical reactions take place when roasting coffee, and volatile gases such as carbon dioxide are formed inside the bean. These gases add flavor to the coffee, but they continue to release for a while. After baking, the carbon dioxide begins to escape, but it takes several weeks for it to completely disappear. This valve allows carbon dioxide to be released and prevents oxygen from entering. This process prevents oxidation and extends shelf life. When carbon dioxide is released, it causes pressure inside the package, which causes the flexible rubber gasket to deform and release the gas. After the release phase is complete, the internal and external pressures are equalized, the rubber gasket returns to its original flat configuration, and the package is sealed again.

The valve also helps you choose your coffee. Because over time the coffee aroma will be expelled through the valve as the carbon dioxide, the smell will become less intense as the coffee ages. If you want to check that the beans are fresh before buying, you can gently squeeze the bag to release the gas through the valve. A strong coffee aroma is a good indicator of whether the beans are fresh, if you don't smell much after a light squeeze, it means the coffee isn't that fresh.