Introduction

Stretch wrapping is one of the most common tools for unitizing products for transport. However, a wrapped pallet that looks good does not mean it is well, most efficiently ‘safety’. Its ability to securely wrap and protect products during storage and transportation.

 

As a product operations manager, understanding the various types of stretch films and their classifications is crucial for producing the right film for customers. Below, we will explore the different types of stretch films so that you can decide which is best for your particular applications and needs.

 

1. Categorization by Packaging Method

Stretch films can be divided into different categories based on how they are used in packaging. Among the primary kinds are:

 

Manual Stretch Film: Ideal for small-scale packaging operations, this method relies on the manual application of stretch film. It is easy to use, reasonably priced, and frequently utilized in shipping departments or warehouses where machinery is not necessary.

 

Machine Stretch Film: This technique is combined with devices that put tension on the film. It is superior to hand film in a number of areas, including as better load confinement, reduced material costs, faster and more efficient packaging, and increased safety.

 

Pre-stretch film: This type of film is made to stretch as much as possible before being put into a load or product. The energy required to produce the same wrapping force is not used by pre-stretch film. It offers excellent load stability due to the fact that it is stretched to its optimal strength during the manufacturing process. It provides tighter and more secure wraps around loads, reducing the risk of shifting during transportation.

 

2. Classification by Material

The material composition of stretch films plays a key role in determining their strength, durability, and environmental impact. The primary types of stretch films based on material include:

1. Polyethylene-Based Stretch Film: The most commonly used stretch film, polyethylene (PE) offers excellent stretchability, high clarity, and superior puncture resistance. Linear low-density polyethylene (LLDPE) is the preferred variant due to its balance of strength and flexibility.
2. Polyvinyl Chloride (PVC) Stretch Film: Known for its strong tensile properties, PVC stretch film is often used for bundling and securing products that require a firm, tight wrap. It is less commonly used compared to polyethylene but still serves niche packaging needs.
3. Ethylene-Vinyl Acetate (EVA) Stretch Film: Offering a balance of stretchability and strength, EVA-based films are often used for packaging fragile or sensitive items where additional protection is necessary.

 

3.Classification by Film Structure

Stretch films can be classified based on their layer structure. The two main categories are single-layer and multi-layer stretch film, each offering distinct advantages.

• Single-Layer Stretch Film: This type has adhesive properties on only one side. It is ideal for securing loads in light-duty applications where less puncture resistance and strength. And it is more affordable due to its simpler production process.
• Multi-Layer Stretch Film: With advancements in film production technology, multi-layer stretch films have gained popularity. This construction is achieved through co-extrusion and lamination. These films offer enhanced performance in terms of stretch, puncture resistance, and load stability. They also allow manufacturers to lower production costs while improving quality, making them the preferred choice for many industrial packaging applications. Nowadays, yuandian produces 55-layer nano stretch film with state-of-the-art cast line from W&H.

4. Classification by Manufacturing Process

The way stretch films are produced can influence their final properties, such as strength, clarity, and stretchability. The main manufacturing methods include:

 

Cast film: This film is made using a comprehensive manufacturing operation called cast extrusion where the film is formed by extruding molten polymer through a flat die onto a chilled roller. The surface of the cast has a high degree of clarity and smoothness, which makes it easier to handle and apply. Compared to the blown method, the cast offers moderate stretchability. Cast film is generally less expensive than blown film because the extrusion process is faster and simpler.

              Clear stretch wrap: This film is made from linear low-density polyethylene. As the name suggests, this film is transparent, allowing for clear visibility of the contents inside the wrap. At the same time, it is one of the most widely used films. Using this transparent stretch wrap, it can see easily the product inside.  It is useful for inventory management and retail display.

              Colored stretch film: This film has bright or custom colors, often used for branding, organization, and aesthetic purposes. The difference in colors makes the product identified and classified. Like opaque stretch film, colored stretch film can provide some level of privacy and security for the contents, especially when the color is dark or non-transparent.

 

Blown film:  This film is a type of film that is produced through the blown extrusion process where molten plastic is extruded through a circular die and inflated into a bubble. After the film cools, the machine stretches both horizontally and vertically the film. Blown film is known for excellent puncture resistance, which makes it suitable for the sharp edge of pallets. However, it has lower clarity and a more complex process than cast.

 

5. Classification by Application

Finally, stretch films are categorized by their specific uses in different industries:

• Industrial Packaging Stretch Film: This is the most widely used kind for packaging goods like electronics, machinery, chemicals, and building materials. Its ability to secure large, heavy loads makes it essential for industrial environments.
• Agricultural Stretch Film: Specifically made for use in agriculture, this kind of film aids in safeguarding crops, fertilizer, and farming implements. It is frequently UV-resistant to endure outside circumstances.
• Consumer Packaging Stretch Film:  This type of film is mostly used for retail and consumer goods.

 

Conclusion

Choosing the appropriate stretch film based on your packaging requirements. Whether you’re looking for manual or machine packaging, taking the material and film structure into consideration, or selecting the best film for your industry. By selecting high-quality and performance stretch film, businesses can increase overall package efficiency, lower material costs, and improve load stability.