1. Polyethylene (PE): This is the innermost layer and comes into contact with the food product. It provides a barrier against oxygen and water vapor, preventing the food from spoiling.
2. Aluminum foil: The middle layer is made of aluminum foil, which acts as a barrier against light and oxygen. It also provides strength and rigidity to the packaging.
3. Low-density polyethylene (LDPE): This layer is sandwiched between the aluminum foil and the outer layer of PE. It helps to bond the aluminum foil to the PE layers and provides additional strength.
4. Cardboard: The outermost layer is made of cardboard, which provides structural support and protects the packaging from damage.
5. Coatings: The cardboard layer may be coated with polyethylene or wax to improve moisture resistance and printability.