How Does A Shrink Wrap Work?

Shrink wrap, shrink film, whatever you call it, the role played in the packaging industry is irreplaceable. It is made of versatile polymer material and is used for finished packaging goods. This packaging material has superb clarity, is wrinkle-free, and glossy and sheen. If you are a retailer, you should definitely order plastic wrapping for packaging your products. Plastic shrink wraps have become a must-have for all shop owners. Let us see how this mechanism works.

How Does A Shrink Wrap Work?

Polymers are long molecules found in plastic that are usually tangled and random. When polymers are made into a plastic film, the molecules are stretched out, almost straight. When heat is applied to the film after wrapping it around an item, either by a conveyor heat tunnel or an electric or gas heat gun, it catalyzes the film to shrink tightly around the object placed within. This gives a clear durable barrier of protection around the item. This mechanism can be explained in terms of molecular behavior. When the molecules of a shrink film sheet or tube are randomly intertwined, they are coiled and twisted with no particular alignment, and when the film is warmed, these structureless regions of the chains are straightened and aligned in the direction of the orientation.

In simple words, we can say that the molecules reorient from their initial random pattern to fit the mold of their contents ultimately. And when cooled, the film’s molecular characteristics are set as per the contents inside. Hence, it remains stretched until sufficient heat energy is applied for the molecular chains to shrink to their original form. We can conclude that a shrink wrap requires the manipulation of molecules.

Advantages Of Shrink Wraps

Shrink wraps provide tamper-proof and moisture-free packaging. They also prevent light exposure to the products. These films form a cover around your items which are sealed using heat. They are a good option for DVDs and CDs as you can still see the cover while the product is completely protected. Crafters, too, can benefit from shrink wraps as they dress up their gift baskets and crafts with a colored shrink wrap while protecting them and also keeping them clear until they are given away. You can order plastic wrapping for packaging either in clear or printed form.

Categories Of Shrink Wraps

Plastic shrink wraps are categorized into four types:

Transit wrap: In this type, the product is passed through a curtain or sleeve of the film, after which the edges of the packing remain open. These edges are sealed using special shrink tunnels. But this method does not create a quality finish, and the product may have a rough display. Such wraps are usually made of polyethylene due to their low cost.

L-seal: This is another packing method, mostly used for display purposes. The L-seal style film has a center-folded film through which the product is inserted. The sealing and cutting are done in an L shape, which seals and cuts the two sides. The wrapped product is tightly packed when it passes through the heat tunnel. Such wraps are usually made from PVC, which has a 40% shrink property on the application of heat. The film is perforated under the L seal to enable air to escape during the shrinking process. This helps the wrap to create an environment devoid of aroma and bacteria. But care should be taken when selling the packaging as the spaces are so small that they cannot be seen easily with our bare eyes. So for better packaging, place the space in a way that wraps the product’s edges.

Flow Wrapping: This system uses the flow wrapping technology rather than the sealing method, under which the film is created around a magazine and loaded at regular intervals into the tube of the film. This creates a seal beneath the pack and the end, thus sealing them up. Such a mechanism is often used for wrapping magazines, which is performed using a shrink tunnel to achieve a skin-tight finfish.

Sleeve Shrink: This method involves dropping a tube of the film over a bottle before it passes through the shrink tunnel. This tube is then pushed down until it fits against the bottle tightly. Such a mechanism can be used as a decorated label and as a security device where the lid meets the jar.

To Wrap Up

Shrink wrapping is done using machines. These machines come in different sizes and operate at different speeds. So make sure you opt for low-cost shrink-wrapping systems, which are operated manually. However, you can also opt for expensive high-speed, fully automatic, integrated systems, integrated tray erectors or loaders incorporated within the shrink wrapper. Thus, you have a lot of options when it comes to shrink-wrapping systems.