Shrink Film, Stretch Film, Shrink Wrap, Stretch Wrap. Aren’t all these the same?
Despite commonly hearing people interchanging this term for the same purpose, it is not true at all. Let us debunk some of the misconceptions that’s lingering around.
Stretch Film | Stretch Wrap
Figure 1 – Stretch Wrap Machine with Stretch Wrapped Pallet
Contrary to popular belief, the above image is a stretch wrap machine with a pallet wrapped with a stretch film. The primary purpose of stretch wrap is to unitize the pallet with the product with the plastic film to ensure that the product stays intact, on the pallet. If you need more information about what is stretch wrap, feel free to read this instead.
Now that we’ve debunked the misconception, everything from here on, we will be focusing on just the Shrink Films.
Shrink Film | Shrink Wrap
What is Shrink Wrap then?
Shrink wrapping is a process of wrapping a product by using just 2 elements, plastic film, and heat. The differences with a stretch wrap, which is applied using force, a shrink wrap is applied using heat and shrinkage of the film (hence the name shrink wrap). We will write posting another blog in the future for science and how shrink film work for those who are looking to understand more. Stay tuned.
By doing this process, shrink wrap provides many different benefits to the users such as
- The appearance of the product (More attractive)
What kind of Shrink film is there on the market?
In our market, there are only 3 main types of films used in the shrink wrapping process, namely
- Polyvinyl Chloride (PVC)
- Polyolefin (POF)
- Polyethylene (PE)
Each of these materials has different characteristics and capabilities that make them fit into specific applications. Let’s go through each of them briefly.
Polyvinyl Chloride (PVC)
PVC was one of the most common types of shrink film available due to its lightweight nature and cost. However, as the name suggests, one of its compositions is chlorine and this is critical. The process of shrink wrapping, which is to heat the film; activates the chlorine. The risks it poses are becoming unacceptable as time goes, causing many countries to start banning this film use.
PVC also has high sensitivity towards temperature, where it can become brittle under low temperature and subject to wrinkling under high temperature.
By looking at the disadvantages, it’s no wonder that its other siblings are replacing PVC.
POF is an extremely durable and versatile film, making it the best choice when doing shrink wrapping. POF is also the film that is FDA-approved food-safe material, making it the best choice for most retailers and food makers to use.
Due to the composition of POF, it has a higher tensile strength. Generally, it is thinner compared to PVC and PE, making it very cost-effective for high-speed use. Within the same reason, the thinner film allows the manufacturer to squeeze more film onto a single roll, making roll-changing in machines less frequent and contributes to higher productivity and efficiency.
PE is a type of film that is usually confused with the stretch wrapping process. Let me break it down into 3 types of PE
High-Density Polyethylene (HDPE)
HDPE is the most common material used in plastic bottles, pipings, and applications that require a high strength characteristic. HDPE is very rare in the shrink wrapping process.
Low-Density Polyethylene (LDPE)
LDE is the go-to film that shrink wrapping process typically use. It’s enormous strength alongside the highly printable characteristic compared to POF, making it the best choice to use for bundling application.
LDPE films are possible to be much thicker compared to POF and PVC. Especially for thick LDPE films, it can be used in special applications such as car and boat wrapping for protection.
However, LDPE has weaknesses too where it has a lower shrink rate (usually around 20% or less) and a lower clarity.
Linear Low-Density Polyethylene (LLDPE)
LLDPE is the type of film that is frequently confused with stretch film. It is the most flexible film out of all the films mentioned earlier, making it the best fit for a stretch wrapping application. Do not confuse this with a shrink film.
What benefits will I get by using a shrink film?
By utilizing shrink wrapping, one can get 3 significant advantages to their operations.
As shrink films are generally durable, this property allows users to protect and safeguard the content of the packaging. Shrink Packaging are also another means to reduce tampering on the product during shipments. Lastly, as one of the final protection property, shrink film well seals and will increase the shelf life on perishable items
Specifically, POF films, there is a lot more benefits in terms of presentation to the overall outcome of your product after it’s being wrapped. For starter, POF film gives a glossy shine that adds attention-seeking appeal compared to those that are non-glossy. As for the food industries, especially the frozen foods, POF film can prevent the ice build-up on the boxes that may damage and spoil the presentation of your product. In addition to that, POF films are much more resistant to fog build-up, hence making sure the product in the frozen aisles are glossy and clear at all times.
One of the major cost reduction that is possible by using shrink wrap is the possibility to reduce most, if not all, of the corrugated packaging from the product bundling process. For example, what used to be a box of water bottles can now be replaced entirely with PE shrink film for bundling without a single corrugated or paper in it. Significant cost reduction comes from this, and as technological advancement in film manufacturing, lower gauges to achieve the same performance are now possible. To know what possibility you could have in your current packaging process, you can always call Syspex for a commitment-free consultation.
If Shrink Films are so good, why isn’t everyone using it?
As good as it can be, there will always be shortfalls in each of the solutions in the market, as there is no one-size-fits-all solution. Let us keep this topic in another post. At the same time, you can contact any of our Syspex’s consultants for more understanding on the right solution for you.