There are several reasons why coffee packaging bags mostly use pure aluminum foil materials:

Strong fresh-keeping performance: Pure aluminum foil has good air tightness and light tightness, which can effectively isolate the influence of oxygen, moisture and light, prevent coffee from being exposed to the air, thereby maintaining the freshness and taste of coffee. This is very important for coffee because coffee beans are susceptible to oxidation and moisture.

Strong barrier properties: Aluminum foil material has excellent barrier properties, which can effectively isolate odors, moisture and microorganisms, prevent external substances from contaminating coffee, and maintain the pure taste of coffee.

Light and easy to carry: Aluminum foil material is relatively lightweight and flexible, making it easy to pack and carry. This is important for coffee packaging because coffee is generally sold in the form of beans or powder and requires convenient packaging to maintain its quality and enable consumers to carry it easily.

Strong sealability: Aluminum foil materials can form a good seal through heat sealing or other sealing methods to prevent the penetration of air and moisture, ensuring the sealing of coffee packaging and extending the shelf life of coffee.

In general, pure aluminum foil material is an ideal choice for coffee packaging due to its superior freshness-keeping properties, barrier properties, lightness, portability and sealability.

Aluminum foil is widely used in coffee packaging mainly because of its excellent freshness-preserving properties. Aluminum foil can effectively isolate oxygen, moisture and light, maintaining the freshness and taste of coffee. In addition, aluminum is a recyclable material, helping to reduce resource waste.

However, aluminum foil also has some disadvantages, such as relatively high cost and environmental production issues. In addition, aluminum foil is opaque and does not provide direct vision into the interior of the package, which may affect consumers' shopping decisions in some cases. Still, manufacturers are weighing the pros and cons and may consider combining with other materials to meet different needs, or looking for more environmentally friendly alternatives to adapt to market trends.