Stretch Film (Stretch Wrap) Buyers Guide - What you need to know ...

Guidelines to buying stretch film?

• “I don’t have time, just ship it out!” (A costly decision!)
• Yes your stretch wrapper is running (but it is probably NOT working)
• Marriage, (the overlooked key to stretch wrapping success!)
• Stretch film and how it relates to the stretch film equipment?
• Is all stretch film created equal?
• What are the most important criteria in choosing a stretch film

I don’t have time just ship it out!

Stretch packaging your finished product for safe shipment is the last process on the production line and thus is often overlooked as an area of cost (and savings).

When we think of stretch wrapping, it is usually in the sense of “wrap it up and get it out”. In our haste to get the product out the door, we typically don’t give it much more thought than that. This can be an extremely costly mistake. Just throwing stretch film over a pallet does not make it unitized and safe for transport. Or you might be applying much more than required with. In fact in the end you could be throwing out thousands of dollars of stretch film that could easily be saved.

Link to SMART WASP

Yes, your stretch wrap machine is running (but it is probably NOT working)

Unlike some other equipment on a packaging line, a stretch wrap machine will continue to run and apply stretch film even though the machine has stopped prestretching the stretch film.

In fact, nearly 60% of all stretch wrap machines evaluated are typically operated far below acceptable efficiency levels. This not only increases the amount of stretch film applied (and thus your packaging cost) but it also dramatically reduces the strength and holding power of the stretch film, resulting in shipping damage due to packaging failure.

How much more stretch film?
“One particular customer saved over $150,000 per year in Stretch Film.”

It is very important to understand the basic fundamentals of prestretching the film to be able to realize that huge potential for cost (and savings) increases in this part of your business. It is worth the 5 minutes of your time to review our section of stretch wrap basics. It will ensure that you know more about the process than the salesman selling it to you.

Was this load wrapped with a properly functioning stretch wrap machine?

It looks good, but this pallet load will fail on the customer’s floor because the stretch film was not prestretched to the required level to obtain the required strength. The point is that although the load looks good it will fail during transit and you simply cannot determine this by looking at the load.

• Are the required load retention forces created by proper prestretching of the stretch film present?
• Have you applied too much film and are actually damaging the product with the stretch film?
• Are you spending too much in stretch film because your vendor simply does not have the necessary grasp of equipment to determine what the issues are?
  

Find out how efficiently your stretch wrap machine is operating! We have provided an online stretch wrap machine efficiency test that will let you know immediately if you are wasting money.
It WILL save you money!

Marriage, the overlooked key to stretch wrapping success!

Stretch film is a raw material whose capabilities are not optimized until properly stretched (Important, see stretch film basics for more info). You can buy the most expensive high performance stretch film on the market, but if your stretch wrap machinery is not prestretching the stretch film at the required level, then your costs skyrocket and your pallets are subject to shipping failure. One simply does not work without the other. It is absolutely critical that you (and your supplier) understand how your stretch wrap machinery and the stretch film work together to create the prestretch film that is required to unitize your product.

If your supplier is not technical enough to review, troubleshoot, and correct issues with your equipment to maximize this marriages efficiencies then find another supplier. He will cost you money in the long run. It is this marriage that maximizes your film strength and holding force while minimizing your stretch film costs!

Stretch film and how it relates to the stretch film equipment?

Stretch film products react differently based on how they were manufactured or the properties of the materials used to produce them. See the stretch film basics section for an overview of these properties.

• You may find a supplier that will sell you a great 2-sided cling stretch film at 3 cents a pound less than your current price. However, your specific stretch wrap machine may not be properly configured to run that product efficiently.
• Or you may find a great deal on a blown stretch film with extra cling, but putting such a stretch film on a high speed wrapping system will surely have the stretch film screaming off the roll and bring the noise level above allowable DB levels in your plant.
• Some carriage designs require that the tacky side of the film be against the prestretch roller to help grip the stretch film during the stretching process, however this may mean that the tack ends up on the outside of the pallet instead of the inside where you require it.

You must understand what your specific requirements of the stretch film are so that you do NOT get “a deal” that costs you more than the 3 cents you saved. If your particular equipment cannot consistently prestretch the stretch film to your minimum requirement to contain your pallet loads then paying 3 cents less for the film has actually cost you money.

Is all stretch film created equal?

NO! Deciding what you require of the stretch film determines the type, grade, and performance characteristics required of the stretch film. If you are a believer of the old adage “Stretch film is just stretch film” then you are probably not getting all the benefits, performance, and economies out of your stretch film. See the stretch film basics section for more info on the different performance characteristics of the various stretch films.

What are the most important criteria in choosing a stretch film?

The ONLY reason to buy stretch film is to ensure your product is safely unitized to get from your dock to your customer’s floor in a manner that is satisfactory to your customer. Some important criteria to consider in choosing a stretch film are:

• Optics
• Cling
• Tear resistance
• Puncture resistance
• Thickness Consistency
• Noise
• Gloss
• Load profile & height

• Load weight
• Storage location (UV?)
• Production speed
• Stacking pattern
• Product value
• Transport distance & method
• Equipment type
• Labeling & bar coding
• Cost

These criteria all have to be weighted before deciding on the correct stretch film for your specific application.

Do not let salesmen cloud the key requirements of your application with a smoke and mirrors presentation that speaks only to prestretch capability or cost. Do your homework first to make sure that any stretch film that is offered meets all the other criteria you have. This way you will ensure that your package meets your customer’s requirements.

The use of stretch hoods offers numerous opportunities for cost savings throughout the entire pallet wrapping process. There are several approaches to saving costs:

• Optimize film: By using film more efficiently, material consumption per pallet and the resulting waste can be minimized. The format, processing and thickness of the film can be examined and optimized. The quality of stretchhood films has constantly developed in recent years due to the use of new materials, which means it often makes sense to check the current status quo of your packaging and thinking about enhancing your film usage.
  • Film format: The film format consists of a long side with a gusset that lies against the short side of the pallet. Due to the increased flexibility of the films, it may be possible to use a smaller format that is expanded further during the packaging process than before and then adapts to the load accordingly.
  • Reduce Film bags: In some cases, 2 stretch hoods are pulled over a pallet for reasons of stability or for weather protection. However, with the right receipe, weather protection can also be achieved with one stretchhood – it depends on the proportions of UV-protecting materials. The stability of the pallets can also be influenced and optimized through the recipe and the use of different materials.
  • Reduce film thickness: Due to the use of new materials and increased flexibility, it is often possible to use a thinner film without losing stability or affecting the reliability of the packaging process. This offers further advantages, as more running meters fit on the film rolls and they have to be changed less often.
• Interaction between film and machine: The above-mentioned film optimizations can only be implemented through the interaction of machine and film. The condition of the machine has a significant influence on the processing of the film and its stretching – it is very important here, for example, that high-quality film grippers are used. If the edges are sharp or the grippers cannot be adjusted precisely, the film cannot be processed optimally.
• Save energy: Operating costs can be saved by switching from a comparatively expensive operation of a hydraulic machine to an electric machine. The frame of the machines can be exchanged and converted from hydraulics to electrics. Switching from shrinkhood to stretchhood also saves a lot of energy because the heating process is no longer necessary. (see more in the last question – 10)
• Extending the lifetime of your machine: With regular service and maintenance it is possible to keep your stretchhood machine up to date, which postpones the purchase of a new stretchhood machine for several years and increases the return of investment (ROI) of your machine. Costly downtime due to sudden problems can be avoided in the long term so that your production always stays in flow. Also major changes through retrofits can extend the life of the machine by several years and make the packaging process more cost-efficient. Retrofitting can not only make your machines more energy efficient, but also process the film better and increase the throughput of pallets to be packed.
• Avoiding transport damage: If goods break during transport between your factory and the customer, costs may arise. Therefore, stable loading unit securing of the pallet and load securing on the truck is very relevant in order to avoid this. If you already have problems in this area, it often makes sense to examine your packaging process closely and optimize the stability of the

Overall, the combination of material savings, lower energy consumption, improved operational efficiency and improved load protection make stretchhood machines a cost-optimized packaging solution. In our DUO PLAST and RHM technology center, your film can be examined in detail and optimized with our stretchhood machine and then transferred to your packaging process at your factory. This means that the machine and film can be optimally coordinated with one another. The processing of stretch hoods is always fully automatic and therefore requires comparatively little personnel effort. Compared to other packaging methods, a high throughput can be achieved in a relatively short time with around 150 packed pallets per hour.

Stretchhood film represents an innovative approach to pallet packaging, continually evolving to deliver diverse gripping and protective outcomes. This multilayer tubular film primarily comprises Linear Low-Density Polyethylene (LLDPE) and sometimes to a lesser extent Ethylene Vinyl Acetate (EVA) polymer. This material offers more flexibility but has a slightly higher cost and in the past there have sometimes been problems with the supply reliability of EVA. This is why metallocene materials are increasingly being used in stretchhoods, as they have better availability than EVA. Furthermore, these materials have been cheaper, but they are currently becoming more and more similar due to demand.

These materials are selected for their impermeability, stretchability, and elasticity. Outer layers are enriched with additives to enhance resistance against puncturing, friction, and ensure sealing and waterproofing, predominantly composed of LLDPE.

There are three primary material types utilized in producing stretchhoods:

• Mainly LLLDPE with a metallocene materials:  This variant offers robustness suitable for conforming to the shape of goods tightly, delivering high holding and restoring forces at a more affordable cost.
• Mainly LLDPE with a Low Percentage of EVA: Offering increased flexibility, this type is favored for packaging shapeless products and meeting specialized requirements. Mainly LLDPE with a low EVA content: This type offers greater flexibility and is favoured for the packaging of shapeless products and the fulfilment of special requirements.
• Stretchhoods Incorporating 30% Post-Consumer Recycled Material: Addressing environmental concerns, these variants aim to minimize their ecological footprint by integrating recycled materials. This initiative aligns with efforts to establish a closed-loop system for polyethylene, ultimately reducing waste through material downsizing and recycling.

By prioritizing sustainability and innovation in material selection and design, the stretchhood film industry endeavors to minimize its environmental impact while delivering effective pallet packaging solutions.

The company is the world’s best High-Quality Super Stretch Film Wholesaler supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.

Depending on the type of load, the Stretchhood provides total support for transport and handling. This is the case for stable pallets (e.g., for sack loads) or light pallets (e.g., for logistics or pharmaceuticals).

If you want to pack your load with stretchhood, there are several ways to check the unit load security of the goods.

In the technology centre of our partner DUO PLAST and RHM, we can check which stretchhood and which machine setting (e.g. stretch) is suitable for your goods. Stretchhood is always secondary packaging, so it is important to check the entire pallet for stability – this means the entire load unit and also the load securing on the lorry. In this way, transport damage can be avoided in the future and material utilisation can be optimised.

We have the following test methods in the technology centre:

• Stretchhood Machine: Adjustments and optimizations can be made to stretchhood machine settings and optimize the entire packaging processes without interrupting production. Various films with different materials and thicknesses are tested to assess stability.
• Horizontal Impact: Simulates important shock and acceleration loads during horizontal transport. Various acting forces can be measured, usually in a range between 0.5 g and 0.8 g, as this corresponds approximately to the forces of a lorry braking on the road. It is also possible to simulate the coupling of rail vehicles or, for example, handling work in warehouses/distribution centres – the tests are possible with forces of up to 15g.
• Vertical Vibration Table: Tests vertical shocks and vibrations to examine load unit behavior under different conditions. This simulates shock absorbers on a lorry, turbulence in air traffic and the effects of processing the load in warehouses.
• Pitch & Roll module: Analyzes stress from tilting movements and rotations, simulating realistic cornering and shipping movements. The Pitch & Roll module is integrated in the Vertical Vibration Table – this interaction makes it possible to cover very application- orientated requirements, as the combination of different loads at the same time creates very realistic test conditions.
• Climatic chamber: Evaluates the influence of climatic conditions on the strength of the packaging and the holding forces, taking into account temperature fluctuations between – 25°C and 80°C and a humidity of between 15% and 98%.
• GPS data recorder: Provides detailed transport route analyses, measuring direct and indirect influencing factors such as forces, accelerations, temperature, and humidity.

If you already have a stretchhood machine, it is possible to carry out a tilt test. This involves lifting a pallet with the stacker on one side and tilting it to a certain angle. However, this test method is very imprecise in comparison.

Thanks to advances in the development of stretchhood films, there are more and more films with increased strength and hold-down force on the market that makes it possible to secure the load with a single hood. The key to securing lies in the properties of the film in combination with the correct stretch application by the stretchhood machine.

Integrating a stretchhood machine into an existing packaging lane involves careful consideration and planning to ensure seamless integration and optimal performance. While the specific process may vary depending on factors such as the layout of the packaging line, the type of products being packaged, and the existing machinery setup, it is generally possible to customize the integration to fit the unique requirements of the operation.

The first step in integrating a stretchhood machine is to conduct a thorough assessment of the existing packaging line. This includes evaluating the available space, the workflow of the line, and the compatibility of the stretchhood machine with other equipment in the line. Based on this assessment, modifications may need to be made to the layout or configuration of the line to accommodate the new machine.

How often a service needs to be carried out on your machine depends, for example, on the usage and the machine model. As a rule of thumb, we recommend one service per year for average use – or even twice a year for very intensive use. There are also service recommendations for certain wearing parts: for example, the sealing bars should be replaced approximately every 30,000-35,000 pallets, as otherwise the risk of fire increases and the sealing seam of the film can no longer be processed properly – the stretchhood can therefore open from above.

A proactive approach to servicing not only ensures the continued reliability of your machine, but also contributes to cost savings by avoiding costly repairs that can result from neglected maintenance. For each stretchhood machine model, we can provide you with detailed service interval schedules to suit your usage.

If your machine has not been serviced for some time, it makes sense to have all wear parts checked by service technicians and to have the condition of the machine checked.

Stretchhood Machines and Shrinkhood machines pallet packaging are sharing only one commonality: the use of a tubular film to safeguard the load. However, they diverge significantly in their operational approach.

In the heat shrink system, a tubular film with shrink properties is applied to the load. Heat is then employed, typically through combustion burners, causing the film to shrink tightly around the load. This process consumes a substantial amount of energy for combustion and necessitates a larger quantity of film relative to the load’s dimensions and thickness.

The Stretchhood machine utilizes a tubular film that stretches to conform to the load without requiring heat. The film’s dimensions are slightly smaller than those of the load, allowing it to compress and secure the load as it is stretched over it. This eliminates the need for heat shrinkage and significantly reduces the amount of film used for protection. Consequently, the Stretchhood method can offer cost savings compared to the shrink hood method, as less energy and material are consumed overall. Additionally, the stretching process with the stretchhood is faster than shrinking with the shrink hood, saving time in the packaging process.

Finally, the stretchfilm machine – a flexible plastic film is wrapped around products or pallets to provide stability and protection to the load. It can be used manually or with a pallet wrapping machine. One advantage here is that the film can be layered more tightly where additional stability is needed – usually at the connection between the product and the pallet. In this way, material savings are also possible if less film is used where less stability is required. This method often results in a lower pallet throughput compared to the stretch hood machine.

• Are you unsure which packaging method is best suited to your packaging requirements?

You are welcome to bring pallets with your goods to our technology centre for testing purposes. There we have a stretchhood machine and various stretchfilm wrappers to find the optimal packaging solution for you. The pallets can then be checked for their stability so that no more transport damage and its resulting costs occurs in the future.