There are numerous types of cheese with diverse characteristics (such as moisture content, fat content, and maturity), and thus their packaging systems are very complex and specialized. The core objective of cheese packaging is to prevent moisture loss, block oxygen (to prevent mold and oxidation), maintain flavor, prevent microbial contamination, and facilitate transportation and sales. Plastic packaging, due to its lightweight, low cost, and strong plasticity, has become the mainstream packaging form for cheese sticks. From the traditional wax sealing method to the modern MAP technology, the choice of packaging directly determines whether the cheese can be presented in the best condition to consumers.
The plastic packaging for cheese sticks usually adopts a composite film structure, composed of multiple layers of materials to meet different functional requirements:
(1) Outer layer (printing layer)
Material: BOPP (biaxially oriented polypropylene), PET (polyester film)
Function: Provides a printing surface to display brand, product information and attract consumers' patterns.
(2) Middle layer (barrier layer)
Material: Aluminum foil (Al), EVOH (ethylene-vinyl alcohol copolymer), coated aluminum film
Function: Blocks oxygen, moisture and light, prolongs shelf life and prevents cheese from oxidizing and deteriorating.
(3) Inner layer (heat sealing layer)
Material: PE (polyethylene), CPP (extruded polypropylene)
Function: Directly contacts the food, needs to comply with food safety standards, and has good heat sealing performance to ensure sealing.
Typical structure examples:
Ordinary cheese stick: BOPP/PE
High barrier cheese stick: PET/AL/PE or PET/EVOH/PE
The plastic packaging for cheese sticks mainly has the following forms:
(1) Single individual packaging
Characteristics: Each cheese stick is separately sealed, convenient for carrying and consumption.
Applicable products: Children's cheese sticks, small portion snacks.
(2) Multi-stick combination (strip or box packaging)
Characteristics: Multiple cheese sticks are packaged in a large package, economical.
Applicable products: Family packs, promotional cheese sticks.
(3) Spout bag packaging
Characteristics: With a suction cup design, suitable for liquid or semi-solid cheese products.
Applicable products: Cheese sauce, suctionable cheese snacks.
The blister packaging for cheese sticks is quite common in the market. This packaging form plays a significant role in maintaining product quality, attracting consumers (especially children), and facilitating consumption.
Common Structure: This type of packaging material may appear ordinary at first glance, but it actually consists of a multi-layer composite structure.
Material Selection: The outer layer is usually a heat-resistant printing material. The middle layer is a thermoforming material, such as special PS (polystyrene) material. The inner layer (the heat-sealed layer in contact with the cheese) requires to be food-grade and easy to peel, and often uses modified PE (polyethylene) or CPP (extruded polypropylene), which should have good heat-sealing performance and easy peelability to ensure that the packaging is easy to open and does not leave residues.
High Barrier Properties: To prevent the cheese from deteriorating (oxidation, moisture absorption, mold growth), the packaging material needs to have high barrier properties. Some high-quality thermoformed composite sheets are coated with high-barrier materials such as PVA (polyvinyl alcohol) or PVDC (polyvinylidene chloride), so that their oxygen permeability can be controlled at ≤ 1ml/(㎡·24h·0.1MPa), and water vapor permeability ≤ 1g/(㎡·24h), thereby effectively extending the shelf life.
