Using aluminum as the inner ply of a paper sack can help keep the product inside fresher for a longer time due to its barrier properties. Aluminum is a highly effective material for blocking the transmission of moisture, air, light, and odors, which are all factors that can negatively impact the freshness and shelf life of certain products.
Here’s how aluminum as the inner ply contributes to preserving product freshness:
Moisture barrier: Aluminum is impermeable to moisture, preventing the ingress of water vapor from the surrounding environment. This is particularly important for products that are sensitive to moisture, such as powdered substances, certain food items, or chemicals. By keeping moisture out, the risk of clumping, caking, or spoilage due to moisture absorption is reduced.
Oxygen barrier: Aluminum also acts as an excellent barrier to oxygen, which is a primary cause of oxidation and spoilage for many products, especially food items. By blocking oxygen, the inner layer helps prevent the degradation of the product’s quality, taste, color, and nutritional value.
Light and UV barrier: Aluminum is opaque and blocks the entry of light and ultraviolet (UV) rays. Some products can undergo chemical reactions or degradation when exposed to light or UV radiation. The aluminum inner ply protects the contents from these harmful effects, preserving their stability and freshness.
Odor barrier: Aluminum helps prevent the transfer of odors from the outside environment to the product inside the sack. This is particularly beneficial when the product is sensitive to absorbing or retaining odors that could affect its quality or taste.
By combining the strength and versatility of paper on the outside with the protective properties of aluminum on the inside, the resulting paper sack provides an effective packaging solution for a wide range of products, including food, pharmaceuticals, chemicals, and more. It ensures that the contents remain fresher for a longer time, extending their shelf life and maintaining their overall quality.