What is Stretch Film?
Stretch film, also commonly referred to as stretch wrap, is a highly stretchable plastic film. Its elastic recovery properties allow it to stay wrapped tightly around items after being applied. It’s frequently used to unitize pallet loads, stabilizing them during storage and transportation. It is also used to bundle together smaller items.
Stretch film is the most efficient and effective way to secure your products and palletized loads. It provides the lowest cost compared to alternative methods of load securement.
Stretch Film Manufacturing Methods
Linear low-density polyethylene (LLDPE) resin is the most common stretch wrap material used in the manufacturing process. There are many different types of polyethylene that have their own unique characteristics. These characteristics affect puncture resistance, elongation, and more.
There are two main extrusion methods used in stretch film manufacturing. These two methods produce blown films and cast films. Due to the advances in cast film technology, many manufacturers have moved towards this method. The cast film extrusion process generally produces superior quality stretch film with more uniform thickness and performance compared to the blown film manufacturing process. Each type of film has its own unique properties and benefits.
Differences Between Blown Film and Cast Film
Blown Film
- Noisy unwind (loud)
- Less gauge control (+/- 10%)
- Not scannable (opaque film)
- Migratory cling passes onto machine and product
- Superior puncture and tear resistance
Cast Film
- Quiet unwind
- Superior gauge control (+/- 4%)
- Scannable (better film clarity)
- Non-migratory cling
- Less expensive to manufacture
Types of Stretch Film
Hand Stretch Film
Film that is designed for manual use is referred to as hand stretch film. It is also commonly called manual pallet wrap, or hand wrap. It is used in lower volume packaging operations that typically wrap less than 15 items per day. Because it is wrapped by hand, it has the slowest application speed and highest risk of injuries.
Machine Stretch Film
Stretch film that is applied by a stretch wrapping machine is called machine stretch film. Films that are applied by machine have many advantages over hand films. These advantages include faster wrapping speeds, reduced material costs, and more uniform securement of loads. There are many benefits to automating the application of your stretch film.
Specialty Stretch Film
There are many films available today that can handle very specific packaging needs. These films don’t fall under any general categories. A few specialty film solutions include UVI protection against sunlight, VCI for protecting metals against corrosion, and vented films to prevent load condensation.
How To Apply Stretch Film
There are many different ways to apply stretch film to your products or pallets. These ways range from handheld all the way up to fully automated and conveyorized stretch wrapping machines. This post goes over a few of the most common wrapping methods.
Hand Film Dispensers
Hand Film can be applied by hand, or with a stretch film dispenser. Stretch Film Dispensers allow easier film application and come in a variety of models that provide things like core extensions, handles, and brakes that provide resistance to the film being applied.
Turntable Stretch Wrappers
Turntable stretch wrappers come in both semi and fully automatic varieties. These machines can be programmed with variable speeds, pre-stretch, and wrap instructions. The load sits on a turntable, which spins and applies the stretch film. The film roll moves up and down to wrap the entire load. Turntable stretch wrappers save time and material costs compared to manually applying the film.
Rotary Arm Stretch Wrappers
Automatic rotary arm machines typically include a conveyor system. These machines automatically load the pallet, apply a seal, and cut the film. The load remains still while the system’s arm rotates around it, applying the film. These types of machines are generally used for light or unstable loads that might topple when rotated on a turntable. These types of stretch wrappers have higher production rates due to their faster speeds and automatic features.
Conducting a Stretch Film Audit
It is important to consider whether or not your film is performing optimally. Performing a stretch film audit will ensure that your operations are running smoothly. There are many factors that can affect your film’s performance. These factors include the handling of the film, age of film, environmental conditions, and more.
Choosing the Right Gauge Stretch Film
Stretch films come in many different thicknesses, also called gauges. Gauge can be converted into other units of measurement that include microns and mils. Typical gauge sizes range from 37 – 150.
There are many questions you need to answer before determining the right gauge for your wrapping operation. You need to know the weight of your loads, the shape of your loads, and the type of stretch film you’ll be using. It’s important to know these factors, to ensure you are using the most cost-effective and safe solution for your wrapping operation.
GAPCO’s expert team of stretch film professionals are able to measure the effectiveness of your current stretch films and recommend alternatives that can save you time and money.
Don’t hesitate to Contact Us Today if you have any questions or concerns about your current stretch film applications. We can help you find the right solutions for your business needs.
