Description
Shrink film, also referred to as shrink wrap, is a versatile polymer material used for the packaging of finished goods. Heat is applied to the film – by either a conveyor heat tunnel or an electric or gas heat gun – which catalyzes the film to shrink tightly around the item placed within. This process results in a clear, durable barrier of protection around the product. Shrink films can be formed into flattened rollstock, bags, overwrap, banding and tubing, and they can add a form of tamper-resistant protection to packaged goods. Here’s a breakdown of the three main shrink film types and their common uses:
The most commonly used shrink is polyolefin. It is available in a variety of thicknesses, clarities, strengths and shrink ratios. The two primary films can be either crosslinked, or non-crosslinked. Other shrink films include PVC, Polyethylene and several other compositions. Polyethylene shrink film is most often used for heavier shrink-wrapping applications. PVC and polyolefin shrink film are most often used within the retail packaging industry.
PVC is the most used shrink film, due to its light weight, and inexpensive capabilities. PVC is durable, and can be used for many different purposes.
Polyolefin or POF shrink film is a premium shrink film, as it’s extremely durable and versatile. POF is puncture resistant, and has a strong seal strength, which allows it to be used for irregularly shaped items. POF is available in 35, 45, 60, 75, and 100, 1 mil gauges. POF shrink film is made from 100% recyclable materials, and is FDA approved. It has great clarity, and a glossy self-appearance, as appearance is critical. POF is great for bundling multiple items together, and has the ability to shrink completely and quickly.
PE, a polyethylene, is used in several forms of flexible protective packaging. There are 3 different forms PE can take place in. These include Low-Density Polyethylene (LDPE), Linear Low-Density Polyethylene (LLDPE), and High-Density Polyethylene (HDPE). For shrink wrapping LDPE would be the best choice, as it has a higher strength, and more durability for heavier items. These wraps can also have graphic images printed on them, and LDPE provides the greatest quality. PE gauges can go all the way up to 1200 , allowing for a great range of gauges. The disadvantage for PE is that it does not have a great shrink rate, and has lower clarity than other wraps. Allowing for a great range of gauges. The disadvantage for PE is that it does not have a great shrink rate, and has lower clarity than other wraps
Shrink film can be supplied in several forms. Flat roll stock can be wrapped around a product, often with heat sealing to tack the film together. Center folded film is supplied on a roll with the plastic pre-folded in half, product is placed in the center portion, the remaining three edges are sealed to form a bag, and the package then heated which causes the bag to shrink and conform to the product. Pre-formed plastic shrink bags have one end open, the product is placed in the bag, sealed, and sent for heat shrinking.
Shrink film can be used to wrap buildings. It can wrap roofs after hurricanes, earthquakes, tornadoes and other disasters. Shrink film can be used for environmental containments to facilitate safe removal of asbestos, lead and other hazards.
Shrink film is sometimes used to wrap up books, especially adult-oriented ones and premium comics and manga, mainly to preserve their mint condition, as casual previewing prior to purchase wears or damages stock, rendering it unsaleable.
Vegetables such as cucumbers can be individually shrink wrapped to extend the shelf life.
Software on carriers such as CDs or DVDs are often sold in boxes that are packaged in shrink film. The licenses of such software are typically put inside the boxes, making it impossible to read them before purchasing. This has raised questions about the validity of such shrink film licenses.
Shrink film is commonly used as an overwrap on many types of packaging, including cartons, boxes, beverage cans and pallet loads. Foam cushioning can be held securely in shrink film, eliminating use of a traditional corrugated box. A variety of products may be enclosed in shrink film to stabilize the products, unitize them, keep them clean, or add tamper resistance. It can be the primary covering for some foods such as cheese, meats, vegetables and plants. Heat-shrink tubing is used to seal electric wiring.
Regarding the usage of shrink film, you could find below link which display how it uses in meat packaging industry.