Polyolefin shrink film is used in a variety of applications. Anything from wire shrink tubing to winter window treatments. For this article, we are talking about centerfold polyolefin shrink film used for packaging applications. We will discuss a few options available and which benefits they offer.
A centerfold film comes on a roll folded in half lengthways. The fold creates a crease in which products can easily slide into for full enclosure once a seal is applied. With an L bar sealer, users seal the open sides of the shrink film with one seal to fully enclose the product. For lower production, an I bar sealer can also be used. To fully enclose the product in a centerfold shrink film the product must be rotated and two seals will need to be made when using an I bar sealer.
Though each polyolefin comes off the rolls the same and can be used on the same machines, they can be very different. What makes them different are the additives and processes during manufacturing. Each polyolefin difference is designed to offer specific benefits. See some of those differences below with examples of products they can be used with.
Economy Polyolefin Shrink Film – An economy polyolefin shrink film is the most common polyolefin shrink film. Normal shrink rates begin close to 330 degrees Fahrenheit. Even economy polyolefin films are FDA approved and safe for direct food contact.
Companies using manual and semi-automatic shrink wrap machines find economy polyolefin (POF) shrink film works fine. Anything from wrapping boxes to baked goods, an economy film will often work.
You can find economy POF shrink films made in many different countries with many varieties of quality. Trying one generic economy line of Polyolefin film does not ensure the next will have the same quality.
Ultimately, testing is the best way to ensure an economy POF shrink film will work for the application at hand. Sampling different thicknesses from multiple suppliers is a great wat to start. Upon finding the right economy film, you may notice a few drawbacks.
Economy polyolefin shrink film does not have superior clarity like better quality films. It becomes noticeable when compared next to other high quality materials.
Pros: Cost, Versatile, Variety
Cons: Quality Issues, Clarity when compared to premium film, Residue left on sealing area
Low Temperature Polyolefin Shrink Film – Made for heat sensitive products, low temperature shrink film is designed to shrink at 250 degrees Fahrenheit or less. The low shrinking temperature with the ability to be used for direct food contact makes low temp POF shrink film a favorite with bakers, confectioners, and more.
Most polyolefin shrink films shrinking at lower temperatures are considered premium films with noticeably better quality than an economy POF shrink film. A low-temperature shrink film can be run on fully automatic machines or manual, and semi-auto machines.
Many food producers choose a lower temperature shrink material to protect chocolates, ice creams, and any other edible items affected by heat. Wrapping heat-sensitive aerosol cans or makeup is another common use for low-temperature shrink film.
The lower required temperature settings also help to reduce wear on machines. Less seal time and heat exposure increase machine life over time. There are some drawbacks though. The seal seams are not the strongest in comparison to other shrink films. Finding the right heat settings can be tedious and burn holes can quickly occur.
Pros: Ran on different machines, great clarity, lower temps help increase machine life
Cons: Seal seams not as strong as other films, Limited to lighter products, easy to obtain burn holes
Crosslinked Polyolefin Shrink Film – During the extrusion process the polymers are crosslinked using rays to transform the structure of the material. The linked polymers are stronger. The increase in seal strength and puncture resistance is obvious when head-to-head with other polyolefin shrink films.
Crosslinked shrink film enables companies to down gauge in material thickness. Companies can wrap more products with less film. The increase seal strength makes thicker crosslinked films a favorite for packaging products and shipping for ecommerce.
The increased strength does require more heat to shrink. Crosslinked shrink film is primarily used with fully automatic machines. Automatic sealers have hot knife settings that work better with a crosslinked shrink film.
The irradiation that crosslinks the polymers in shrink film helps to add clarity as well. Crosslinked film is know for superior clarity. High production bakeries, food production lines, and more choose if for a crystal clear display.
Of course crosslinked shrink films do have their own drawbacks as well. The increased seal strength can lead to wrap rage and cause customers to become frustrated when opening a package. The increase sealing and shrink temperatures can be hard on machines over time. Lastly, the cost is often the highest of polyolefin shrink films because of the manufacturing process.
Pros: Excellent clarity, Great for High Speed Production, Superior Strength
Cons: Increased Heat Exposure, Too strong of seals, High Cost
Conclusion
These are only a few options for centerfold polyolefin shrink film. Others are stronger or offer anti-fog properties, breathable, etc. The key point is a polyolefin shrink film can have many different qualities for accommodating a wide range of packaging needs.
If you feel shrink wrapping is the right solution for your products, try at least one or two centerfolded polyolefin samples to see which runs the best. Different machines and products work better with different films. For more information, shop online at uspackagingandwrapping.com or call 1-800-441-5090.
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