For many end-of-line packaging professionals, the choice of pallet packaging method may not immediately surface as a critical success factor when designing, upgrading or refurbishing a production line or distribution center. There are many aspects that should be considered when choosing a pallet packaging method, as the choice can significantly impact overall profitability and distribution chain performance.
There are three recognized methods available for pallet packaging: conventional spiral stretch-wrapping, heat shrink-hooding, and stretch-hooding. Each method has its advantages and disadvantages depending on the specific application. In the final part of the series we will examine stretch-hooding. You can read parts one and two, if you missed them.
Stretch-hooding
Introduced in the late 1980s, the stretch-hooding method of pallet packaging has, over the past decade, gained significant market share at the expense of heat shrink-hooding and spiral stretch-wrapping -- not only for bagged products, but also for products in Octabins, cases, pails, and other similar primary packaging formats. The primary reason for this is that stretch-hooding provides superior value with respect to operating costs, speed, reliability, and distribution chain performance.
The quality of today’s domestically-available, co-extruded stretch-hood films allows for pre-stretch percentages exceeding 80 percent, providing better film yields than what was possible even a few years ago. This performance, combined with film thickness reduction down to 1.6 mils, means that the per-pallet film cost with stretch-hooding is extremely competitive with that of spiral stretch-wrapping. And the stretch-hood equipment can be programmed to allow for application-specific selection of a non-sealed sleeve (for lowest possible film consumption), a closed hood (for optimal protection and stability), or even an open hood (to avoid moisture condensation for food packaging).
The hood is formed from gusseted tubing, and the height of the pallet load is measured automatically as the pallet enters the machine -- ensuring that only the amount of film required for the application is precisely dispensed. Among other operating benefits, energy consumption is very low since the film is not heated, and available servo drive technology further reduces energy and maintenance costs.
The high quality of today's films means that a single film hood format can, within certain limitations, be used to stretch-hood multiple pallet sizes. However, it is important to analyze the net financial benefit of a one-size-fits-all approach, as the total film cost will be lower if each pallet size has a dedicated film hood format.
Unlike spiral stretch-wrapping, stretch-hooding provides ready evidence of tampering, as it is not possible to remove a product from the pallet without tearing the film. The smooth film surface also provides for easier loading and unloading of trailers. With spiral stretch-wrapping, the friction between the films on two pallet loads can cause tears and film tails to come undone, compromising the integrity of the pallet load.
For products sold at retail outlets, such as home centers, the clear, one-layer, stretch-hood film provides much better product recognition at point-of-sale than multi-layer spiral stretch-wrap film does. It is also possible to print advertising or handling instructions on the stretch-hood film. And stretch-hood film allows for easy bar-code scanning, virtually eliminating misreads and associated remedial costs.
Consistently maintaining its tension, stretch-hood film is particularly well-suited to products that, due to their physical properties, tend to settle after being bagged and palletized.
Recent advancements in stretch-hood technology have reduced film cost per-pallet-load, while simultaneously offering more intuitive user interfaces, reduced energy consumption, smaller machine footprints, and throughputs exceeding 150 pallet-loads-per-hour. Modular designs also allow for faster, and less costly, installation. In addition, the use of intuitive graphic user interface screens helps with ease of operation and troubleshooting. For example, BEUMER has implemented features that allow the machine operator to switch between different international languages with the touch of an onscreen flag icon. Furthermore, the operator can select metric or U.S. units.
Cost of ownership
Properly evaluating the choice of pallet packaging method goes far beyond comparing equipment acquisition costs. Several factors can significantly impact the cost of ownership and, consequently, the return on investment.
Equipment cost. Spiral stretch-wrapping equipment is available in multiple speed ranges and varying degrees of automation. With prices ranging from below $10,000 for semi-automatic low-speed models to $120,000+ for high-speed rotary-arm or satellite models, there is generally a spiral stretch-wrapping model for every budget.
Heat shrink-hooding equipment also comes in both semi- and fully automatic models. The price range is generally between $50,000 for semi-automatic models (where the operator applies a pre-made shrink bag over the pallet load) and $200,000+ for fully automatic, high-speed models.
The price of stretch-hooding equipment has come down somewhat over the past couple of years due to increased competition and the development of simpler equipment. Prices range from roughly $140,000 for single-format equipment to $200,000+ for multi-format equipment. For high-output facilities, it is important to realize that one single stretch-hood machine can replace multiple spiral stretch-wrap machines due to the higher achievable speeds.
Film cost. If protection and stability are secondary, the film cost for spiral stretch-wrapping a pallet load can be very low because of minimal film thickness and comparatively high pre-stretch percentage. Where protection and stability are critical, however, multiple layers of stretch-wrap film must be applied for stability, and a top-sheet added for protection. This can greatly increase film cost per pallet.
Heat shrink-hooding is significantly more expensive in film cost per pallet than either of the other two methods because of the need to oversize the film hood prior to shrinking. The film cost per pallet for shrink-hooding can easily exceed that of stretch-hooding by 40 percent or more. And substantial energy costs associated with heat shrink-hooding add to the cost-disadvantage of this method.
For stretch-hood film, recent developments have enabled the use of much thinner films with significantly higher pre-stretch percentages than was previously possible. This makes stretch-hooding competitive with spiral stretch-wrapping in terms of film cost per pallet load for applications where moderate load stability and protection is required.
Labor and maintenance cost. Spiral stretch-wrapping equipment is simple to operate and maintain. Semi-automatic models, in particular, require little training for operation. Maintenance costs, however, tend to the high side because of the quantity of moving components. The drawback of spiral stretch-wrap equipment is that the relatively low-volume film rolls require frequent replacement at higher throughputs. Some manufacturers do offer an automatic film change option; however, this cancan be an expensive option, adding complexity to the equipment. Having to replace the film roll at short intervals reduces line availability and increases direct labor costs. The resulting costs from outdoor storage, or measures to protect from the weather, can be significant and must be included in a total cost-of-ownership analysis. Heat shrink-hooding equipment is moderately maintenance-intensive in comparison with spiral stretch-wrapping and stretch-hooding, as heat shrink-hooding involves more wear parts that require replacement at regular intervals.
The least labor-intensive method of pallet packaging is stretch-hooding. The film roll can be up to 39-inches in diameter, easily allowing for 10 times longer film change intervals and increasing line availability. Troll change is a very simple procedure typically taking no more than 10 minutes to return the machine to production. Unlike stretch-wrapping, adjustments to machine settings are rarely necessary, thus ensuring consistent high-quality packaging results. Moreover, with fewer wear parts than stretch-wrap machines, stretch-hooding equipment requires very little maintenance, and five-sided protection eliminates the need for tarping.
Making the choice
Making the right choice of pallet packaging method involves a thorough analysis of many factors that influence not only the daily operating costs, but also the entire distribution chain performance. When product leaves the production facility, it is at its highest value-added state and should arrive at the customer’s facility in the same condition.
For low-throughput applications, where stability and protection are secondary to initial acquisition cost, spiral stretch-wrapping still provides an attractive alternative. However, if production line efficiency, protection against the elements, superior stability, and product recognition at point-of-sale are important criteria, then stretch-hooding is the preferred solution as it offers the best combination of packaging performance and total value of ownership.
There are three recognized methods available for pallet packaging: conventional spiral stretch-wrapping, heat shrink-hooding, and stretch-hooding. Each method has its advantages and disadvantages depending on the specific application. In the final part of the series we will examine stretch-hooding. You can read parts one and two, if you missed them.
Stretch-hooding
Introduced in the late 1980s, the stretch-hooding method of pallet packaging has, over the past decade, gained significant market share at the expense of heat shrink-hooding and spiral stretch-wrapping -- not only for bagged products, but also for products in Octabins, cases, pails, and other similar primary packaging formats. The primary reason for this is that stretch-hooding provides superior value with respect to operating costs, speed, reliability, and distribution chain performance.
The quality of today’s domestically-available, co-extruded stretch-hood films allows for pre-stretch percentages exceeding 80 percent, providing better film yields than what was possible even a few years ago. This performance, combined with film thickness reduction down to 1.6 mils, means that the per-pallet film cost with stretch-hooding is extremely competitive with that of spiral stretch-wrapping. And the stretch-hood equipment can be programmed to allow for application-specific selection of a non-sealed sleeve (for lowest possible film consumption), a closed hood (for optimal protection and stability), or even an open hood (to avoid moisture condensation for food packaging).
The hood is formed from gusseted tubing, and the height of the pallet load is measured automatically as the pallet enters the machine -- ensuring that only the amount of film required for the application is precisely dispensed. Among other operating benefits, energy consumption is very low since the film is not heated, and available servo drive technology further reduces energy and maintenance costs.
The high quality of today's films means that a single film hood format can, within certain limitations, be used to stretch-hood multiple pallet sizes. However, it is important to analyze the net financial benefit of a one-size-fits-all approach, as the total film cost will be lower if each pallet size has a dedicated film hood format.
Unlike spiral stretch-wrapping, stretch-hooding provides ready evidence of tampering, as it is not possible to remove a product from the pallet without tearing the film. The smooth film surface also provides for easier loading and unloading of trailers. With spiral stretch-wrapping, the friction between the films on two pallet loads can cause tears and film tails to come undone, compromising the integrity of the pallet load.
For products sold at retail outlets, such as home centers, the clear, one-layer, stretch-hood film provides much better product recognition at point-of-sale than multi-layer spiral stretch-wrap film does. It is also possible to print advertising or handling instructions on the stretch-hood film. And stretch-hood film allows for easy bar-code scanning, virtually eliminating misreads and associated remedial costs.
Consistently maintaining its tension, stretch-hood film is particularly well-suited to products that, due to their physical properties, tend to settle after being bagged and palletized.
Recent advancements in stretch-hood technology have reduced film cost per-pallet-load, while simultaneously offering more intuitive user interfaces, reduced energy consumption, smaller machine footprints, and throughputs exceeding 150 pallet-loads-per-hour. Modular designs also allow for faster, and less costly, installation. In addition, the use of intuitive graphic user interface screens helps with ease of operation and troubleshooting. For example, BEUMER has implemented features that allow the machine operator to switch between different international languages with the touch of an onscreen flag icon. Furthermore, the operator can select metric or U.S. units.
Cost of ownership
Properly evaluating the choice of pallet packaging method goes far beyond comparing equipment acquisition costs. Several factors can significantly impact the cost of ownership and, consequently, the return on investment.
Equipment cost. Spiral stretch-wrapping equipment is available in multiple speed ranges and varying degrees of automation. With prices ranging from below $10,000 for semi-automatic low-speed models to $120,000+ for high-speed rotary-arm or satellite models, there is generally a spiral stretch-wrapping model for every budget.
Heat shrink-hooding equipment also comes in both semi- and fully automatic models. The price range is generally between $50,000 for semi-automatic models (where the operator applies a pre-made shrink bag over the pallet load) and $200,000+ for fully automatic, high-speed models.
The price of stretch-hooding equipment has come down somewhat over the past couple of years due to increased competition and the development of simpler equipment. Prices range from roughly $140,000 for single-format equipment to $200,000+ for multi-format equipment. For high-output facilities, it is important to realize that one single stretch-hood machine can replace multiple spiral stretch-wrap machines due to the higher achievable speeds.
Film cost. If protection and stability are secondary, the film cost for spiral stretch-wrapping a pallet load can be very low because of minimal film thickness and comparatively high pre-stretch percentage. Where protection and stability are critical, however, multiple layers of stretch-wrap film must be applied for stability, and a top-sheet added for protection. This can greatly increase film cost per pallet.
Heat shrink-hooding is significantly more expensive in film cost per pallet than either of the other two methods because of the need to oversize the film hood prior to shrinking. The film cost per pallet for shrink-hooding can easily exceed that of stretch-hooding by 40 percent or more. And substantial energy costs associated with heat shrink-hooding add to the cost-disadvantage of this method.
For stretch-hood film, recent developments have enabled the use of much thinner films with significantly higher pre-stretch percentages than was previously possible. This makes stretch-hooding competitive with spiral stretch-wrapping in terms of film cost per pallet load for applications where moderate load stability and protection is required.
Labor and maintenance cost. Spiral stretch-wrapping equipment is simple to operate and maintain. Semi-automatic models, in particular, require little training for operation. Maintenance costs, however, tend to the high side because of the quantity of moving components. The drawback of spiral stretch-wrap equipment is that the relatively low-volume film rolls require frequent replacement at higher throughputs. Some manufacturers do offer an automatic film change option; however, this cancan be an expensive option, adding complexity to the equipment. Having to replace the film roll at short intervals reduces line availability and increases direct labor costs. The resulting costs from outdoor storage, or measures to protect from the weather, can be significant and must be included in a total cost-of-ownership analysis. Heat shrink-hooding equipment is moderately maintenance-intensive in comparison with spiral stretch-wrapping and stretch-hooding, as heat shrink-hooding involves more wear parts that require replacement at regular intervals.
The least labor-intensive method of pallet packaging is stretch-hooding. The film roll can be up to 39-inches in diameter, easily allowing for 10 times longer film change intervals and increasing line availability. Troll change is a very simple procedure typically taking no more than 10 minutes to return the machine to production. Unlike stretch-wrapping, adjustments to machine settings are rarely necessary, thus ensuring consistent high-quality packaging results. Moreover, with fewer wear parts than stretch-wrap machines, stretch-hooding equipment requires very little maintenance, and five-sided protection eliminates the need for tarping.
Making the choice
Making the right choice of pallet packaging method involves a thorough analysis of many factors that influence not only the daily operating costs, but also the entire distribution chain performance. When product leaves the production facility, it is at its highest value-added state and should arrive at the customer’s facility in the same condition.
For low-throughput applications, where stability and protection are secondary to initial acquisition cost, spiral stretch-wrapping still provides an attractive alternative. However, if production line efficiency, protection against the elements, superior stability, and product recognition at point-of-sale are important criteria, then stretch-hooding is the preferred solution as it offers the best combination of packaging performance and total value of ownership.
