Shrink Film vs Stretch Film is a common dilemma in the packaging industry for companies looking to protect their products. These two solutions are widely used and have different purposes.
Both solutions have many things in common: on one hand, they are a packaging wrap that is used to give products cohesion for a convenient transportation (e.g., on pallets), offering solutions to guarantee a safe cargo; on the other, they are both made out of polyethylene resins.
However, the differences between them are significant, and you should know them if you want to apply a solution that leads to a safe and effective packaging.
Differences: Shrink Film vs Stretch Film
Use as a plastic wrap packaging
Due to the properties of both materials, stretch wrap and shrink film are used for different purposes.
The main feature of shrink film is that, once applied, it contracts in order to girdle and contain the products inside it. For this reason, end consumers know it as a way to bundle several bottles or cans into a single pack. It is also useful to wrap large industrial machinery.
On the other hand, stretch film is most commonly used to bundle and secure a series of products for their transportation or storage on a platform (usually a pallet), acting as a tertiary packaging and pallet wrap.
Shrink film is generally manufactured out of low-density polyethylene (LDPE), which allows it to contract when correctly applied. On the other hand, stretch film is manufactured using linear low-density polyethylene (LLDPE), which allows it to stretch.
Shrink film requires activation through heat, and it can be applied using a shrink wrap machine and through other means.
As for stretch film, it can be applied either manually or by using a stretch wrap machine. The latter allows for much more stretching, reaching a 150 to 300% stretch when applied as plastic wrap for pallets.
It is once applied that film testing enters the picture. It allows you to determine which characteristic the film must have to effectively fulfill its purpose (e.g., its thickness or caliber).
Here is where cutting-edge technology comes in to help determine the best way to attain a safe package for your products. This includes the performance of impact simulations, and incline or horizontal stability testing – all of these, hazards that are commonly found during the transportation of pallet packing.
Furthermore, by using Artificial Vision Systems, it is possible to accurately calculate the deformation of the load unit and apply the necessary changes to guarantee the safety of the goods being transported.
Moreover, these tools make it possible to optimize the use of shrink and stretch film, in order to generate more economic and environmentally-friendly packaging solutions.
Benefits of shrink film in packaging
Shrink film is commonly used to girdle products and create packs for consumers (such as bottle and can packs, as well as pharmaceutical packaging).
The main benefits of shrink film are the added protection that it offers against dust, environmental changes or tampering, in addition to generating a more efficient transportation.
It is also a very enduring material that, when applied as pallet shrink wrap using a machine, can effectively prop up and contain the goods inside it, further avoiding issues such as product piercing.
Benefits of stretch film
The main benefit of stretch film is that it offers an effective method to contain products for transportation or storage, including boxes or other formats, on a pallet.
Since stretch film is available in many different forms (with a different length, width and caliber), it is a highly versatile option that can be optimized through material testing in order to achieve load stability.
When using a pallet wrapping machine, stretch film enables companies to automate the packing process, consuming less resources when compared to those who do not use a palletising machine.
Do you want to learn more about Shrink Film vs Stretch Film and know the right method to apply for a safe cargo? At Safe Load Testing Technologies we offer companies the possibility of optimizing their packaging through the use of simulation technologies. Contact us and let’s talk about how we can help you.