Detailed Production Process Of Barrier Shrink Film

Barrier shrink film is a multi-layer co-extruded plastic film designed to protect the product from external factors such as oxygen, moisture, and contaminants. Its main function is to maintain the integrity and freshness of the product.

A key material for barrier shrink films

1. Polyvinylidene chloride (PVDC)

PVDC is a key ingredient in high barrier shrink films because of its superior oxygen and moisture barrier properties, which ensures that the product stays fresh for a long time due to its superior barrier properties.

2. Polyethylene (PE)

Polyethylene is often used as the outer layer of barrier shrink film due to its excellent sealing properties and flexibility. It helps to create a durable and resilient packaging material that can prevent the material from breaking.

3. Polypropylene (PP)

Polypropylene is another important material that strikes a balance between strength and transparency. It is used in combination with PVDC and PE to enhance the balance of the barrier shrink film.

Manufacturing process

1. Squeezing

The manufacturing process begins with the extrusion of the primary material. Extrusion involves melting plastic polymers and forming a continuous film. This step is essential to create a uniform and consistent substrate for the barrier shrink film.

2. Co-extrusion

In the case of high-quality barrier shrink films, co-extrusion technology is used to combine multiple layers of different polymers. This process ensures that each layer contributes specific properties to the final product, such as barrier protection, strength, and flexibility.

3. Directions

Orientation consists of stretching the film in both the machine direction (MD) and transversely (TD). This step aligns the polymer molecules to enhance the strength and transparency of the film. Orientation is essential for the formation of a film that shrinks evenly when heated.

4. Annealing

Annealing is a heat treatment process that stabilizes the film after orientation. It consists of heating the film to a specific temperature and then cooling it slowly. This step ensures that the film retains its shape and properties during subsequent processing and use.

5. Slitting and rewinding

After annealing, the film is cut into narrow widths according to customer requirements. The slitted film is then rewound onto a roll ready for further processing or shipping.

Application of barrier shrink film

1. Shrink wrap for seafood

Barrier shrink film is widely used in seafood shrink wrap due to its excellent barrier properties. It protects the seafood from oxygen and moisture, prevents spoilage and preserves the freshness of the product. High barrier PVDC shrink film is particularly effective in this application because it provides superior protection for products that require corrosion protection.

2. Meat and poultry

Meat and poultry packaging benefits greatly from the use of barrier shrink films. The film's ability to prevent oxidation and contamination ensures that these products maintain their quality and extend their shelf life. This is critical for both retailers and consumers as it maximizes product safety.

3. Cheese and dairy products

Cheese and other dairy products are special products that require packaging that protects them from the growth of mold and bacteria. Barrier shrink films extend shelf life by creating a controlled environment while maintaining the all-important flavor and mouthfeel. Therefore, for dairy products, barrier shrink film is the best packaging material.