An overview of PVDC blown film and its characteristics

PVDC blown film refers to a type of plastic film made from Polyvinylidene Chloride (PVDC) resin using the blown film extrusion process. PVDC is known for its exceptional barrier properties against moisture, oxygen, and other gases, making it an excellent choice for packaging materials where preserving freshness and preventing spoilage or contamination are critical. Here's an overview of PVDC blown film and its characteristics:

Blown Film Extrusion Process:

1. Material Selection: The process starts with PVDC resin pellets, which are typically blended with other additives and resins to achieve desired properties such as flexibility, clarity, and barrier performance.

2. Extrusion: The PVDC resin blend is heated and melted in an extruder, where it is forced through a circular die to form a tubular shape, similar to a large bubble.

3. Inflation: As the molten PVDC tube exits the die, it is rapidly cooled and inflated with air. This inflation process stretches and thins the film while maintaining its circular shape.

4. Cooling and Solidification: The inflated film passes through a cooling system, which solidifies the material, setting its thickness and characteristics.

5. Flattening and Winding: After cooling, the tube is flattened into a sheet and wound onto rolls for further processing or converting into various packaging formats.

Characteristics of PVDC Blown Film:

1. High Barrier Properties: PVDC blown film exhibits excellent barrier properties against moisture, oxygen, and other gases. It provides an effective barrier to protect packaged products from spoilage and contamination.

2. Transparency: PVDC film is typically transparent or translucent, allowing consumers to see the contents of packaged items without unwrapping.

3. Flexibility: It is a flexible and pliable material, making it suitable for wrapping and conforming to the shape of packaged products.

4. Heat Sealability: PVDC films can be heat-sealed, creating a secure and airtight seal to maintain product freshness.

5. Chemical Resistance: PVDC is resistant to chemicals and solvents, which enhances its suitability for packaging applications.

6. Temperature Tolerance: PVDC films can withstand a wide range of temperatures, from freezing conditions to elevated temperatures used in cooking or reheating.

Applications of PVDC Blown Film:

PVDC blown film is used in a variety of packaging applications, especially for products that require extended shelf life and protection from external factors. Some common applications include:

1. Food Packaging: PVDC film is used for wrapping and packaging a wide range of food products, including meats, cheeses, snacks, and bakery items.

2. Pharmaceutical Packaging: It is employed for the packaging of pharmaceutical products, ensuring product integrity and shelf stability.

3. Industrial Packaging: PVDC blown film is used for packaging industrial and chemical products due to its barrier and chemical resistance properties.

4. Medical Packaging: In the medical field, PVDC film is used to package sterile medical devices, pharmaceuticals, and diagnostic products.

5. Agricultural Films: PVDC blown film is used in agriculture for creating greenhouse covers and agricultural mulch films, providing protection and controlled environments for plants.

PVDC blown film is valued for its ability to protect products from external factors, extend shelf life, and enhance the visual appeal of packaged items. It is an essential packaging material in industries where product quality and preservation are of utmost importance.