Difference Between Shrink Film and Stretch Film
Leave a CommentMany types of goods are packaged or bundled with thin polymer films for protection during shipping and storage. Shrink film and stretch film are common examples, but they are made from different materials and serve different purposes.
Here, we’ll look at how they differ, some available options, and how they are typically used in different industries.
Shrink Film
Shrink film, or shrink wrap, is a versatile packaging material that shrinks to mold to the shape of its contents when heat is applied. It is generally used to wrap single product items for individual sale or use. Shrink wrap plastic is available in center-fold or tubular forms on rolls, or as pre-measured bags in different sizes. Shrink wrapping produces a durable and clear barrier to protect the product inside while letting consumers see the contents.
In general, the plastic must be heated to around 300°F to begin the shrinking process. Heat catalyzes the molecules in the film, causing them to align and shrink around the object. While it can be applied with hand-held heat guns, shrink wrap machines that cut and heat seal in one operation are more efficient. These use a conveyor or heat tunnel for quick and even heat distribution.
Materials
Shrink films are made from the following materials:
- Polyethylene: A type of polyolefin often used with heavy products and for bundling; lower shrink rate than other options
- Polyolefin: Safe for food and non-food products; strong and low-odor film; cross-linked polyolefin is highly clear and sterile
- Polyvinyl Chloride (PVC): Only for non-edible products; must be used with proper ventilation due to hydrogen chloride release; cost-effective
In addition to the film material, there are several important considerations when selecting the most suitable shrink film for an application. These include film gauge (i.e., thickness), moisture vapor transmission rate (MVTR), shrink temperature, shrink rate of the material, how much pressure the shrunken plastic applies to the product inside, and tear or puncture resistance.
Applications
Shrink film is used in many industries for a range of products such as:
- Electronics
- Food
- Games & Sporting Goods
- Hardware & Housewares
- Printing & Paper Products
Benefits
Shrink film offers various advantages for packaging, including:
- Cost reduction over boxes, cartons, and other options
- Presentation of products in a tidy and secure package that can be seen through
- Protection against component loss, breakage, or spoilage
- Sustainability of recyclable plastic
Stretch Film
Stretch film, or stretch wrap, is a flexible and stretchable plastic film that can be wrapped around products to bundle and protect them during shipping and storage. It is often used to secure groups of boxes, bags, or single large objects on pallets. It can be applied by hand or with automated or semi-automated packaging equipment.
Plastic stretch film is available in several gauges and widths and can be purchased pre-stretched for ease of application. Specialized types of stretch film are available for UV protection, ventilation, anti-static buildup, and color preference or opacity.
Materials
Stretch films can be made of several types of polyethylene, the most common being linear low-density polyethylene (LLDPE). Depending on the application, low-density polyethylene (LDPE) or high-density polyethylene (HDPE) may deliver improved performance.
Applications
Stretch film is used in many industries for these and other purposes:
- Pallet wrapping
- Protecting items from dirt, dust, or moisture
- Securing rolling or mobile items during storage and transportation
- Color coding pallets or bundles, blocking UV exposure, or obscuring contents from view
- Bundling small or like items for more efficient storage and shipping
Benefits
Stretch film offers several benefits, such as:
- Cost-effectiveness
- Durable product protection from tampering, loss, or damage
- Efficient transportation and storage of goods
- Recyclable plastic is sustainable
- Reduces injury risk from falling products
Why Choose Alpha Packaging, Inc.
Shrink film and stretch film are two effective ways to package and protect items. Manufacturers and producers rely on them to minimize damage and loss and to keep products organized.
Alpha Packaging, Inc. provides a full range of packaging supplies, products, and materials including shrink and stretch films. We also manufacture corrugated board and cardboard boxes, mailers, shipping boxes, and pizza boxes. Additional services include custom packaging, printing, and foam inserts.
Contact us to learn more about our catalog and manufacturing capabilities, or request a quote to get started today.