Packaging considerations for successful intermodal transport
As CPG manufacturers and retailers seek new ways to reduce shipping costs, they encounter a number of variables throughout the development process. From designing new product and unit packaging to choosing the best way to transport it, they must find a way to satisfy consumer expectations while ensuring the packaging will protect the product throughout the supply chain.
In an effort to reduce cost while increasing sustainability, many of these businesses are turning to intermodal transportation for their shipping needs. Intermodal, which involves moving freight in a single container using at least two modes of transportation including rail, is more fuel efficient than shipping via truck, therefore it’s less expensive and more environmentally friendly.
But with so much variability in the supply chain – from different transit routes, to mixed load cargo to varying loading plans – it’s critical to scientifically analyze packaged products to help ensure successful arrival when shipping via intermodal transit.
Predictive package and distribution testing helps brand owners understand the potential for damage, so they can better balance the competing interests of lowering their costs to move products while protecting them at the same time. These tests allow shippers to address potential issues before they become problems, which could result in loss of product and money in the form of unsaleable goods.
Intermodal on the rise
Rail intermodal transport has seen undeniable growth in the last four years. While it has always been a common choice for heavy freight such as coal and paper, a growing number of consumer goods and food companies are looking to it for their transit needs.
Several factors are driving companies to the rails, but the top factors in the CPG world are cost and sustainability. Because rail is four times more fuel efficient than truck transport, long hauls across country can see a cost savings of 60 percent when moving freight off the roads and onto rail. There are other benefits as well. As companies work to achieve sustainability objectives, they find significant improvements in reducing environmental footprint via intermodal over truck transport. For example, moving freight with trucks produces eight times more carbon emissions than rail.1
Packaging trends and transit performance
Cost and sustainability are also affecting the packaging used to protect products in transit and on shelf. A growing amount of primary packaging has been light-weighted to use less material, so it is less expensive to transport and more environmentally friendly. But there is a balancing act. As people try to pull costs out of moving freight as well as out of the materials used to protect that freight, manufacturers employ new packaging strategies that can create problems with the protective properties of those packages. From 1995 to 2007, the estimated amount of money lost in retail sales due to unsaleable products – a large component of which is damaged product – rose from $12 billion to $36 billion.2 Those dollars indicate a significant opportunity for improvement in supply chain damage control.
Because most packaging professionals focus on product and unit load package design, one factor that’s often overlooked is the shipping container it will be moving in, as well as how it is loaded. In addition to the primary package, case and even the unit load configuration, designers must also recognize that the load will go into another container and there will be other elements around it, including void space, that will challenge the sidewall rigidity of those containers. It is an important factor that is often forgotten in predicting damage rates during intermodal transport.
Rail hazards to consider
To optimize results when shipping via intermodal, retailers and brand owners also need to consider the conditions their package systems will need to withstand. Most manufacturers understand there will be compression, shock, vibration and temperature hazards when shipping. While many standard tests address those issues, additional factors should be taken into account to get a more accurate prediction of damage.
Rail vibration in the vertical axis is often tested because it can be a major factor in truck transport, but it is much less severe in rail. Horizontal vibration, however, is often overlooked in testing. This movement is more prominent in rail because as the train wheels hunt back and forth for the rails, it causes horizontal movement that can have an adverse effect on freight.
More damage can arise from horizontal shock impacts, which can be caused by factors including railcar coupling and shunting. These shock pulses can vary in shape and cause different responses in the packaging system, so it is important to predict the effects of both long and short duration impacts.
Horizontal compression is also often overlooked in the rail environment as well. There are a lot of issues that appear to be a vertical compression issue where the root cause isn't vertical input; it is actually the result of a horizontal hazard or impact. Void space and lack of sidewall rigidity are common causes in these situations.
For example, if a rail car is shunting as it slows or stops, it creates low-level horizontal impacts. While the energy is not enough to overcome the coefficient of friction between the deck of the rail car and the pallet, it is enough to shift the top of the unit load. This back-and-forth shifting puts a moment of force on the sidewall of the unit, which can result in a compressive failure.
Removing void space through dunnage applications can also concentrate compressive forces in areas that are undesirable. Too much void space will cause items to shift or topple over. But filling up that void space and point loading will create horizontal forces that can cause issues, especially if the packaging has been light-weighted and its sidewall rigidity has been compromised. This problem is especially prevalent with tin cans, which are notorious for damage in the rail environment today. Because they have been downgauged over the years, the ribbing is designed to withstand vertical stacking, but not horizontal compressive forces that can come from the application of dunnage.
Thorough testing pays off
While standard distribution testing can identify many areas of vulnerability, there is room for improvement. Testing laboratories offer a wide range of custom tests that can provide a closer look at some of these forces to help improve outcomes and reduce damage. It is important to employ a testing regimen that addresses all hazards and can identify hazard rates, so that shippers can better predict changes in the damage rate caused by altering packaging and moving from truck to rail.
The best way to predict what will happen in the supply chain is by employing testing that has a very strong correlation to the supply chain. Creating hazard maps and aligning the hazards with the operation identifies the hazards and testing can be applied that correlates to them. The resulting output helps shippers determine whether the damage rate will increase, decrease or stay the same if a change is made. If a dramatic increase exists, the manufacturer may consider a package redesign in order to help products perform better in light of those hazards.
Balancing the cost of moving goods and the cost of protecting them is important. To do that, it is necessary to understand the cause and effect of making a change. With the right package testing and the right information, brand owners can make sound decisions regarding redesigning packaging, deciding which supply chain mode they should be using, or employing a custom combination of both.