No matter what type of business you look at, you can always expect to see stretch film being used for everything from securing pallets and stillage during transport, to protecting equipment and machinery from dust and moisture while they’re in storage.
Stretch wrap is made from extremely flexible, linear low-density polyethylene (LLDPE) and wound on corrugated cores that allow it to be dispensed either manually or automatically. Its durability and high tensile strength not only make it one of the most versatile forms of packaging ever developed, but its UV and chemical resistance properties make it the perfect bundling material for a range of environments that would render other packing materials completely ineffective.
Not all stretch films are the same, though, and if you’re in charge of ordering packaging consumables for your organization, you don’t want to order a film that lacks the holding qualities that your business or warehouse needs. Taking a moment now to become familiar with the differences is going to help you feel confident about both making the right purchasing decision, as well as about choosing the right supplier to purchase your film from.
The Right Stretch Wrap Solution
Whether it’s to maximize the amount of product you can store in a warehouse, or to minimize the amount of product that’s lost due to pilferage, stretch wrap is going to keep all your products safe and organized. You need to ensure, however, that you’re using the correct extrusion type of stretch and pallet wrapping film for your particular application, and that it’s also in the proper micron thickness.
There are two extrusion processes used to make stretch film, casting and blowing, and they differ as much in their performance characteristics and cost, as they do in their production methods. A lot of organizations aren’t aware that there are differences between wrapping films, or that one type of film isn’t inherently “better” than the other.
Your reason for needing the film, the conditions it’ll be used under, and even the method that’ll be used to apply it are all going to determine which film is ideal for your organization. Fortunately, the one thing you can be certain of is it that a good packaging supplier is going to have a solution for any wrapping contingency that you have.
Cast Stretch Wrap Film
Cast film is produced by continuously extruding (feeding) hot LLDPE forms through a flat die and onto rollers where it cools, solidifies, and is trimmed down to rolls. Increasing or decreasing the rolling speed varies the film’s micron thickness, but it’s during the cooling process that cast films develop their most common qualities, including:
· High gloss and transparency;
· Quiet unrolling characteristic; and,
· The ability to cling from either side of the foil.
Cast film rolls are ordinarily sold in lengths of up to 520m for manual dispensers and up to 1900m for automatic wrapping machines, and among the traits they’re preferred for are:
· They stretch easier. With less elastic memory and tear resistance, cast film can be applied faster.
· They have excellent clarity. Clear film lets you easily view the product, or scan a barcode through it.
· They have less weight. A film that’s not massively thick can be layered to replicate thicker micron film.
The production process is also less intensive with a cast pallet wrap film which, along with a reduced ecological impact, ultimately means it costs less.
Blown Stretch Wrap Film
Blown film is produced by extruding LLDPE through a circular die to create a polymer tube that’s filled with air, and slowly allowing to cool as rollers flatten the tube to create the final product. The diameter of the tube determines the film’s micron thickness, allowing a blown film to be formed that’s significantly stouter than a cast one, with other qualities that include:
· Higher loading and stretch capacity;
· Greater capacity to cling to itself; and,
· Higher elastic memory that allows it to remain stretched longer.
Blown film rolls are manufactured in lengths of up to 400m for manual dispensers and up to 1500m for automatic wrapping machines. It’s their added thickness, however, that reinforces the core durability quality of blown films, including:
· Better puncture resistance. Blown films are ideal for products with sharp edges and corners.
· Better bonding. Products can be stacked and wrapped higher because of the increased cling.
· Long term wrapping. Higher memory film allows products to remain wrapped for extended periods.
Unlike the high level of clarity that comes with cast wrap, blown pallet wrap is naturally opaque. And while blown wrap can be purchased in black, its inherent lack of transparency gives it a host of other environmental and security advantages like:
· Added protection from light and UV exposure;
· Prevention against unwanted product attention and chances of tampering; and,
· A reduction in problems with photoelectric sensors that prefer reading from opaque surfaces.
Invariably, because more resources are used in the manufacture of blown wrap, it also costs more than its cast equivalent. However, if you need the additional strength and privacy that blown wrap has to offer, there’s no substitute.
Stretch Wrap Thickness
Along with the extrusion type, pallet shrink wrap thickness is the other parameter you need to be aware of. Film thickness can be measured in a variety of scales, but the most common units are micron (mu), gauge (ga), and millimetres (mm). Just like with the extrusion type, one thickness isn’t inherently “better” than another. Depending on your product, using a wrap that’s too thick could be more problematic than using a thinner one, so you’ll want to consider all the applicable aspects before you sign a purchase order.
There are four main thicknesses that quality stretch pallet wrapping suppliers will have:
· 17mu (70ga) – Typically rated for wrapping 2200lb–2400lb product loads.
· 20mu (80ga) – The most common thickness of stretch wrap, and rated for 2200–2400lb product loads.
· 23mu (90ga) – Typically rated for wrapping 2400-2600lb product loads.
· 25mu (100ga) – Typically rated for wrapping 2800-3000lb product loads.
In short, you always want to use the strongest possible pallet stretch wrap available that won’t damage your product. It’s a small detail, but it’s going to make a big difference in how your products are cared for and delivered.
The Final Word
At the end of the day, if your business is stretch wrapping product, it’s because you want to avoid the risk of losses and damages, and possibly even personnel injuries due to mishandled or unsecured material. Stretch wrapping eliminates these concerns, but only when you have the right wrap for the job.
Getting the wrapping film that’s correct for your business processes is going to save you time, material and money. That’s also why you want to speak with a packaging supplier who’s going to have the right wrap for your application. They’ll have precisely what you need to put your wrapping and packing concerns behind you.