What are the types of shrink film?
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Shrink film is a packaging material made of polymeric plastic film. When heated, it shrinks tightly over whatever it is covering. Shrink wrap and shrink film are very versatile materials that can be used for a variety of packaging applications. Some common uses for shrink wrap are for packaging food, gift baskets, boxes, toys, books, soap, etc.
If you want your products to be sold safely and securely, you may have seen that shrink film can help you do just that. There are a variety of shrink films on the market today, so it's important to choose the right type. Choosing the right type of shrink film will not only help protect your product on the shelf, but it will also enhance the buying experience for your customers or buyers.
Of the many types of shrink film available, the three main types of film you will want to look at on the market are PVC, polyolefin and polyethylene. Each of these shrink films has properties that span different applications, but the specific characteristics of these films may make them better suited for your particular use.
Here are some of the pros and cons of each shrink film to help you choose the one best suited for your application.
PVC (also known as polyvinyl chloride)
Advantages:
This film is thin, flexible, lightweight and usually more affordable than most shrink films. It shrinks in only one direction and is very resistant to tearing or puncturing. PVC has a clear, glossy appearance that makes it aesthetically pleasing to the eye.
Disadvantages:
PVC will soften and wrinkle if it gets too hot, and it will harden and become brittle if it cools. The FDA only approves PVC film for non-edible products because of the chloride content in the film. This also causes it to give off toxic fumes during heating and sealing, so it must be used in a well-ventilated area. As a result, this film also has strict disposal standards. PVC is generally not suitable for bundling multiple products.
Polyolefin
Advantage:
This shrink film type has been approved by the FDA for food contact because it is chloride-free and produces much less odor during the heating and sealing process. It is better suited for irregularly shaped packaging because it can shrink more fully. The film has a beautiful, glossy surface and is very clear. Unlike PVC, it can withstand a greater range of temperature fluctuations when stored, which saves inventory. Polyolefin is a good choice if you need to bundle multiple items, and it is highly resistant to punctures and tears. Cross-linked polyolefins can also be used, which add strength without sacrificing transparency. Polyolefins are also 100% recyclable, making them a "green" choice.
Disadvantages:
Polyolefins are more expensive than PVC films and may also require perforation in some applications to avoid air pockets or uneven surfaces.
Polyethylene
Some additional information: Polyethylene film can be used for shrink film or stretch film, depending on the form. You need to know which form you need for your product.
Polyethylene is created when manufacturers add ethylene to polyolefins in a polymerization process. Polyethylene comes in three different forms: LDPE, or low density polyethylene, LLDPE, or linear low density polyethylene, and HDPE, or high density polyethylene. They each have different applications, but typically the LDPE form is used for shrink wrap packaging.
Advantages:
Good for packaging heavy multi-packs, such as large quantities of beverages or water bottles. It is very durable and can stretch more than other films. Like polyolefins, polyethylene is approved by the FDA for food contact. While PVC and polyolefin films are limited to 100-gauge thicknesses, polyethylene can be expanded to 1200-gauge, making it ideal for wrapping vehicles, such as boats, for storage. Uses range from bulk or frozen foods to garbage bags and palletizing as stretch wrap. Consult your manufacturer to find out which form you should use (LDPE, LLDPE, HDPE).
Disadvantages:
Polyethylene has a very low shrinkage rate of about 20% and is not as clear as other films. It is more expensive than other films. Polyethylene shrinks when heated and cooled, so extra cooling space must be left at the end of the shrink tunnel.