Selecting the Right Stretch Wrapper
While the fundamentals of wrapping a load are nearly universal, selecting the right wrapper for your specific requirements involves many variables.
Wrapping is simple…but, its complicated.
While the fundamentals of wrapping a load are nearly universal, selecting the right wrapper for your specific requirements involves many variables.
The purpose of a stretch wrapper is simple – unitizing a load to prepare it for shipment. At its simplest, a stretch wrapper applies stretch film to a pallet load of product. Some machines rotate the load on a turntable while others have an arm that rotates around the load. But getting the right amount of film with the right amount of tension, what we call containment force, everywhere on the load is more complicated than it often seems.
The outcome is critical, though – if you don’t get the right amount of containment force everywhere on the load, the time and expense of wrapping could be wasted. Loads that are ineffectively stretch wrapped have unnecessary risks of falling apart during shipment. So we encourage companies to find the right machine for their application. And there are lots of choices!
Two Basic Types of Stretch Wrappers
Straddle Stretch Wrappers
These use a wrap arm to rotate film around a stationary pallet.
Turntable Stretch Wrappers
These rotate the pallet while the film moves up and down the mast.
Finding the Right Wrapper Doesn’t Need to be Difficult
In fact, sometimes there are several appropriate solutions. But selecting at random, even just getting “another one like the last one”,
skips some steps that we know from experience are important.
Some things to consider:
- Load (pallet size and types, weights, dimensions, product, shipping considerations)
- Production environment (temperature, moisture, pallets per hour, loading and unloading, film thickness, forecasts for growth)
- Other related processes (weighing, labeling, tracking)
Questions to help gradually exclude machines:
- Is a turntable or straddle machine best? Or does it matter?
- Do speed or line requirements dictate efficient loading, unloading, starting and stopping?
- Will the machine exchange data with other factory or warehouse systems?
Further refine machine selection and options:
- How might conveyor sections improve efficiency?
- What’s the benefit of weighing a load in-line?
- Does your company give operators control, or do they prefer to lock down the controls and rely on the machines to optimize wrapping?
80/20 decisions to be made:
- If you normally wrap about 25 loads per hour but during peak shipping hours in the afternoon, production doubles, that’s important.
- If most of your loads are 40″x 48″ pallets and are 60″ tall, but one customer requires you to wrap a 96″ tall load, that’s critical.
- If 20% of your shipments are non-standard loads that each require weighing to ensure accurate paperwork, that can introduce even more choices.
Speed vs. Automation
Why does the industry conflate these two considerations?
Sure, it’s true that often to increase output speed it’s necessary to automate functions both for efficiency and safety. But nowhere is it written that slower means more manual.
For instance, our XT series of wrappers are “semi-automatic” according to industry terminology, but allow a driver to simply drop a pallet and remotely hit a start-button; the machine takes it from there. Whereas, operations with warehouse management systems (like inline check weighing, automated labeling and load tracking functionality) require the process controls of an automated line – even if they’re only wrapping a relatively small number of loads per day. And even “50 loads/day” means different things to different companies. Two loads of high value product every hour from a three-shift operation has very different production implications than the frantic presentation of 50 picked loads during 30 minutes of chaotic shipping at a distribution center.
Automatic vs. High Speed
For the person hand-wrapping a pallet, the dream of an “automatic” process simply means some kind of machine. For the carbonated soft drink bottler, 50 pallets/hour is so slow it grinds production to a halt.
“Automatic”, “Semi-Automatic” and “High Speed” are terms that suit the stretch wrapper industry but don’t help you much. In fact, in the real world of wrapping their meaning depends entirely on context.
So we break down stretch wrapper output into three general categories by loads per day:
Less than 40 loads per day – our popular Q Series semi-automatic turntable, and S Series semi-automatic straddle wrappers are good places to start. All will handle the demand. Selecting between them requires considering details of future growth and load specifics.
40 – 100 loads per day – in this range, there’s often more than one right answer. The choice often comes down to a company’s growth and automation plans, and the philosophy on workplace environment.
- Our XT models of both the S Series straddle and the Q Series turntable wrappers incorporate a number of options which boost efficiency and increase output. They’re appropriate for stand-alone wrapping such as on loading docks and in work cells. In many cases, they will adequately handle the volume assuming the flow of product is consistent over a shift or two. Although, there is often an inherent limitation in the necessity to remove a completed pallet before placing another.
- For wrapping in-line with other processes or for operations that desire a system which will allow material handlers to stage loads for wrapping while removing completed loads (all while the stretch wrapper is operated independently) the Q Series turntable automatic and S Series straddle automatic stretch wrappers provide higher throughput capacity AND autonomous operation to enable maximum material handling efficiency.
Greater than 100 loads per day – our highest speed wrappers include optimized versions of our S Series automatic and our Ring Straddle.
Load Considerations
Size of the Load
Length, width & height of your loads all impact what machine you need. Height is one of the most common considerations we see. Standard wrappers handle loads up to 80″ tall. But some stretch wrappers have options to wrap loads up to 140″ tall.
Turntables start at 65″ in diameter (which encompass standard 40″ x 48″ pallets within its perimeter – a huge safety factor) and go up to 96″ in diameter to handle larger loads.
Stability and Weight of the Load
If loads are really heavy, light, or unstable, it makes more sense to keep the load stationary and rotate the stretch film around it. These machines are called straddle wrappers. Most pallets, however, are wrapped on turntable machines which rotate the pallet while the film is applied. Turntable and straddle wrappers come in various sizes to accommodate different sizes of load perimeters.
Forklifts vs. Pallet Jacks
If you have to load the machine with a pallet jack, then you could use a straddle type stretch wrapper that will keep the load on the floor, or add a ramp to a turntable machine.
Options to Take You Further
Once you’ve chosen the type of stretch wrapper, it’s time to consider various options to reduce the burden on your warehouse team. By cutting and clamping the film automatically, for instance, you can save them from having to get on and off their forklift and the bending and twisting it takes to attach and cut the film. Using these tools reduce wasted labor and opportunities for injury.
And if you weigh your loads, you can build a scale into the wrapper to save space and reduce extra time consuming steps.
Other Considerations
The Manufacturer
There are many different stretch wrapper manufacturers. These include domestic or foreign, very small manufacturers or divisions of the F500 companies, family owned or publicly traded, and more!
Consider some key factors in evaluating them:
- Number of machines in the field
- Loyalty (how many customers return to buy another machines)
- Pricing
- Local support and service
- Warranty
- Availability of replacement parts
Distribution Network
You don’t always buy directly from the stretch wrapper manufacturer. Lantech relies on local distribution partners to sell and support our stretch wrappers. Our experience is that the local relationship not only provides a connection to supply film and other related supplies, but also ensures rapid response and continuity of service when technical support requirements arise. Give us a call anytime to get connected to a distributor in your local area.
Other Resources
Lantech Blogs
Stretch wrapping Beer? What a buzz kill.
In high volume beer distribution centers, efficient loading and unloading and effective stretch wrapping is a must. See how our Low-profile Drag Chain Conveyor system can overcome challenges associated with plastic pallets and unstable, slick loads.
'Hard' to Keep Up - Case Study
Cider was once the fastest growing alcoholic beverage category. Producers were having a difficult time keeping up with demand and getting products out. This hard cider producer improved productivity and saved money with a semi-automatic stretch wrapper.
