When it comes to shipping, one of the most common packaging materials is stretch wrap. Also called stretch film, it is used to wrap items on pallets, securing those products to themselves and the pallet itself throughout the shipping process or during storage. This reduces product damage and loss, as well as discourages pallet tampering and pilferage.
Typically, stretch wrap is used to hold boxes together on a pallet for transportation. However, it can also be used to protect products during storage as well. Stretch films comes in a variety of sizes (referred to in gauges), is manufactured using different methods, and is applied in two separate ways — by hand or with a machine. It is also offered in a a variety of specialty styles.
The two most commonly used types of stretch wrap are cast stretch wrap and blown stretch wrap.
Below, you'll find the major differences between the two, as well as the primary advantages of each.
Cast stretch wrap is manufactured using a cast extrusion process. Cast extrusion is a continuous technique during which thermoplastic material is melted and extruded through a flat die onto a chilled roll, where it is quenched and re-solidified. Cast stretch film has excellent clarity, requires less force to stretch, offers increased tear resistance, unwinds quietly from machines, and boasts a superior cling. There are both machine grade and hand grade cast stretch films available.Advantages:
Blown stretch wrap is manufactured using the blown extrusion process. The melted plastic material is extruded through a die, usually vertically, to form a thin walled tube. Air is introduced via a hole in the center of the die to create a balloon-like structure. On top of the tube, an air ring blows onto the stretch film to cool it as it comes off the line. This process allows blown wrap to be tougher and more resilient than cast stretch wrap. Blown stretch film typically has a greater load containment force.Advantages:
No matter whether you use cast or blown stretch wrap or whether you manually apply stretch wrap or use equipment instead, using stretch film to secure your pallets for shipment offers a diverse range of advantages.
Did you know? The saran wrap that you use at home is approximately the same as 40 gauge stretch wrap. That gauge of stretch wrap could secure around 1,000 pounds on a pallet load.
Did you know? Your Ziploc sandwich bag is approximately the same as 150 to 200 gauge stretch wrap. That gauge of stretch wrap could secure up to a 3,500-pound pallet load.
Traditionally, manufacturers made a standard gauged stretch film for customers to use that was affordable and worked well to secure a variety of loads. That standard most often ranged from 60 gauge to 150 gauge, and was able to secure between 1,500- and 3,500-pound loads. Over the years, 80 gauge stretch film became the industry standard and is now known as the most versatile stretch film thickness on the market.
Today's most common options include:
For years, before petroleum prices got out of hand, standard or true gauged wrap was what most manufacturers produced. Today, you have to specifically request it. This standard stretch wrap offers a great amount of stretch, tear resistance, and strength. However, using standard hand stretch also comes with unnecessary waste because users cannot reach the maximum stretch potential of the wrap. Better, more economical options are found in the other types versus this traditional wrap.
This film is often called different names by different manufacturers, but, in general, is considered an equivalent film. It typically comes in a 57, 60, or 63 gauge. The main contrast between this stretch wrap and traditional wrap is the thickness of the material and the amount of stretch potential. A micron stretch wrap is often stiffer and will not stretch as much as standard wrap. However, the micron stretch wrap is more affordable, stronger, and often promotes less waste.
Like eco stretch wrap, hybrid stretch film is also considered an equivalent that can replace lower gauged wraps, typically coming in a 47, 51, or a 53 gauge. It is stiffer and has less tear resistance than micron film. The major benefits include a lower purchase cost, lighter rolls, less physical exertion when applying, and a stronger wrap. Its multiple layers make the film stronger than a true gauged film of the same thickness, but it does not come in higher gauges.
An excellent, green option for users wrapping lighter loads is pre-stretched stretch wrap. It is a true 80-gauge film that has already been stretched to up to 90% of its potential before being placed on the roll and shipped to the user. This makes it an affordable film that promotes less waste because users can reach the full stretch potential when applying the film with little physical exertion, meaning less film usage for maximum protection. Pre-stretched wrap is typically recommended for loads no heavier than 1,200 lbs.
Occasionally you’ll hear about the potential to save money by “down-gauging” your stretch film. It's possible that this could save you a few dollars, but every situation is different and you should only attempt to down-gauge with the help of a trained professional. Lowering your gauge may inadvertently cause you to use more wrap, meaning you'll see no savings and you may actually be putting your pallet loads at risk of damage. That being said, there is also a potential that you may benefit and see more cost savings by actually increasing the gauge of your stretch film.
It’s important to remember that there are many hidden costs associated with down-gauging, which is why we only recommend undertaking the process with help from a packaging professional.
Lighter gauge stretch films are more likely to experience breaks, either from machine variations, edge damage during handling, or defects. Will you have to spend extra on labor costs because you have to keep restarting the wrapping process after a break in the film? Will you need multiple wraps to cover those film nicks and ensure the load integrity? All costs have to be considered.
Thorough testing should be completed before considering switching to a lower gauge. Weight, pallet configuration, and packaging environment must play a role in considering a lower gauge wrap. Loads can change over time, affecting your packaging during both storage and shipping. If your pallets and products aren't receiving protection, then down gauging hasn't saved a thing.
If you're ready to start looking into including stretch wrap equipment at your facility, IPS Packaging & Automation has put together an eBook with all the essential information you need to make the most informed decision. It will:
Stretch wrap machines save money through material and labor savings, as well as improve load stability and decrease damage rates. And if money is the biggest concern, know that when correctly utilized, most equipment pays for itself in less than a year.