Brick carton packaging, formally known as aseptic cartons, is a multi-layer, shelf-stable packaging system primarily used for liquid foods and beverages like milk, juice, soup, and wine. Its iconic rectangular shape is designed for space-efficient storage and transport. The structure is a sophisticated lamination of typically six layers: from the outside in, it consists of polyethylene (PE) for moisture protection, paperboard for rigidity and structure, another layer of PE, a critical barrier layer of aluminum foil (which blocks oxygen, light, and aroma), another PE layer, and finally an inner layer of food-contact PE. This composite material is formed, filled, and sealed in a continuous, sterile process on specialized aseptic filling machines, allowing products to be packaged without refrigeration for up to a year.

The process and benefits of brick carton packaging are highly significant. The aseptic processing involves ultra-high temperature (UHT) treatment of the liquid product to sterilize it, which is then filled into pre-sterilized cartons in a sterile environment. This eliminates the need for preservatives and refrigeration throughout distribution, leading to massive energy savings and a vastly extended shelf life. The packaging itself is extremely lightweight and efficient, with a product-to-package ratio far superior to cans or glass bottles, reducing transportation costs and carbon footprint. While recycling infrastructure for the composite material (often called Tetra Pak after a leading manufacturer) is improving, with facilities capable of separating the paper fibers from the plastic and aluminum, it remains a challenge compared to single-material packaging. Nonetheless, its combination of food safety, logistical efficiency, and material economy has made brick carton packaging a global standard for preserving and distributing liquid food products.