Stretch Film vs. Shrink Film: The Difference

If you are new to packaging, you may be confused about the difference between stretch film and shrink film. After all, if they are both made of plastic, how different can they be?

Although shrink and stretch are sometimes mistakenly used interchangeably, there are significant differences between the two packaging methods.

What is Stretch Wrap?

Stretch wrap is a thin, stretchable plastic film (typically made from polyethylene) that is used to lock and secure cased goods onto a pallet. As the stretch film is wrapped around the pallet, tension is applied, enabling the film to extend its length by up to 300%. This tension then creates a constrictive force around the load, allowing it to be held in place.

Types of Stretch Wrap

1. Hand Stretch Film
Hand stretch film is specifically designed to be applied manually and is therefore typically utilized in low-volume packaging operations.

2. Machine Stretch Film
Machine stretch film is film that is specifically designed to be applied with a stretch wrap machine and is typically utilized in high-volume packaging operations. Some common types of machine stretch film include:

• ·  Blown Stretch Film – Manufactured using a blown extrusion process. This process involves blowing heated resins into a bubble. The bubble is then transformed into sheets that are rolled and applied to a core tube.

• ·  Cast Stretch Film – Manufactured using the cast extrusion process. This process involves feeding heated resins through a line of cooled rollers which then solidifies the film.

• ·  Pre-Stretched Film – Film that has been pre-stretched during the manufacturing process.

What is Shrink Wrap?

Shrink wrap is a plastic film typically used to package individual products—such as toys, DVDs, fresh produce, or frozen foods—rather than cases of goods. When heat is applied, the film shrinks to tightly fit the product, creating a secure and protective wrap.

Types of Shrink Wrap

There are two common types:

1. Polyolefin – Offers minimal odor, excellent clarity and appearance, durability, and versatility. Ideal for freezer applications and printable for branding.

2. Polyethylene – Has lower clarity than other films but is thicker and highly durable. It tightens around the product when exposed to cool air at the end of the packaging process, providing strong protection for shipped goods.

Benefits of Stretch Wrap

1. Reduced Shipping Damages – Goods that are being shipped can be subject to an array of events that have the potential of damaging them. Stretch film aims to reduce these hazards due to its ability to hold loads tightly together onto the pallet so that they do not shift as much while in transport.

2. Protection Against the Elements – Stretch film also works to protect goods from environmental damage such as dirt, dust, and moisture.

3. Sustainability – Many types of stretch film are recyclable.

4. Cost-Effective – Compared to other packaging methods like strapping, stretch film can be a cost-effective alternative.

5. Versatile – The stretchy characteristics of stretch wrap enable oddly-shaped or hard-to-stack loads to be wrapped.

Benefits of Shrink Wrap

1. Product Protection – Shrink wrap keeps contaminants like dust and moisture at bay.

2. Tamper Evident – Any tampering with a product will be immediately noticeable.

3. Increased Branding Space – Many shrink films can be custom printed to include a business’s branding.

4. Extends Shelf Life – Shrink film (when utilizing modified atmosphere packaging) can extend the shelf life of fresh produce by preserving and preventing spoilage.