|We learned on the first day of science class that experimentation and testing are foundations for the scientific method. Those lessons from so long ago remain important today for any company using packaging materials to get products to their destinations free from damage. At a time when businesses are focused on a number of factors related to their packaging, such as sustainability and cost, it is important to keep in mind that performance is the number one objective of these materials and directly related to these factors. Packaging testing and experimentation is paramount for this reason, as it is the best way to determine and/or ensure package performance. |
Background Research: Looking into Standardized Package Testing
There are number of options for package testing, and consequently, a number of standardized testing processes. ASTM International (formerly the American Society for Testing and Materials) and ISO (International Organization for Standardization) have developed and published test standards and procedures that are used around the world every day, but ISTA, the International Safe Transit Association has developed into a leading authority in the industry. ISTA oversees the certification of packages, packaging professionals and testing labs, developing testing guidelines for all types of shipping scenarios from small parcel, to freight and palletized and non-palletized shipments.
A number of packaging material manufacturers, third party testing labs and product manufacturers operate ISTA-certified testing facilities. For example, Sealed Air maintains 24 ISTA-certified testing labs as part of their global network of 35 Packaging Design & Development Centers (PDDC's) supporting customers with professional certified packaging design and testing services.
The most popular package tests are conducted for packaged products weighing up to 150 lbs. The ISTA Procedure 1A is a basic integrity performance test that's been around for more than 20 years. ISTA Procedure 3A has been around for at least 8 years and is primarily supported by UPS for shipments of small parcels via their service. Additionally, 6-FEDEX-A Procedure is a test utilized for packages sent via FedEx.
Initial Observations: Packaging Materials Testing
The first and most important type of packaging-related testing focuses on the packaging materials. In order to develop high-performing packaging designs that are both economical and an efficient use of packaging materials, it is important to work with a packaging designer who has a solid understanding of the performance of the materials themselves. Cushioning materials are run through various shock tests to measure their performance. The most common cushioning materials test is test ASTM D1596, which involves dropping a weighted platen from various drop heights onto cushion samples. Another common test performed on cushioning materials is ASTM D4168, which is specifically designed for testing of polyurethane foam-in-place packaging materials and is conducted in a corrugated container. The transmitted shock data captured during both of these tests is used to create "cushion curves", which indicate peak product accelerations (measured in G's) for different cushion thicknesses, drop heights and static stress (measured in lbs./in2 or g/cm2). This information is particularly valuable for a package designer, as cushion curves are the foundation for each and every traditional cushioning packaging design.
Further Analysis: Validating Packaging Performance
The second form of packaging-related testing is used to validate the performance of a packaging design. Depending on the results from these testing efforts, significant steps can be made to further reduce the costs or materials associated with the packaging as a designer zeros in on the best solution. Packaging testing is available for packaged products of all shapes and sizes, for all weights, configurations and shipping methods. Test procedures typically submit packaging to a series of shock, vibration, compression and atmospheric conditioning testing.
Shock testing (a.k.a. drop testing) is the most familiar and common package testing process. Typically, a drop test is performed using a free-fall drop tester or via a mechanical shock test system. In either case, the package is dropped at least once on each face, and in some cases, on corners and edges. Drop heights for most shock tests are specified based on whether the package is shipped unitized (on a pallet) or individually. Also considered is the shipper type, whether full trailer load, less than truckload or small parcel (UPS, FedEx, USPS, etc.). Package weight also is a big factor in determining drop height, with heavier the packages generally testing at lower the drop heights. The reasoning here is based on whether a package is likely to be carried or moved at waist-high or via low conveyor or by hand or fork truck.
Vibration testing is typically performed on either a basic mechanical system or a more sophisticated hydraulic vibration system. The basic mechanical test is based on a simple fixed displacement repetitive movement achieved by attaching a motor to a table upon which the package is placed. The package is subjected to 14,200 (ISTA 1A) quick repetitive vertical and horizontal movements. This method is common, but is not an effective means of identifying or solving package problems due to vibration. A more effective vibration test is usually performed by a certified packaging lab professional using a hydraulic vibration system. Such systems can simulate actual transportation conditions on the road, rail, sea or air. Test procedures such as the ISTA 3A test call for vibration tests referred to as "over the road" and "pick up and delivery vehicle" spectrums. Such testing is often performed with a top-load of significant weight to simulate vibration while under the weight of a stack of packages in a trailer.
While top-load vibration testing is used to indicate how well a package performs under stacked conditions throughout transit, additional compression tests specifically measure how much weight a package can handle before it buckles and fails. This compression data is critical for stacking in storage and distribution.
Temperature and Humidity Testing
Because the performance of corrugated containers and paper-based protective packaging materials can be significantly affected by temperature and humidity, most packaging testing procedures offer options for atmospheric conditioning to simulate storage and shipping in temperate or humid environments. In these scenarios, packages are placed in temperature and humidity controlled environments for prescribed amounts of time prior to testing.
Deducing Source Reduction: Identifying Both Over and Under Packaging
Validating package performance through testing provides feedback critical to finding a balance between package durability, product protection and source reduction. Through testing, packaging designers can identify under or over packaging scenarios. While inadequate protection in shipping can lead to costly product returns and repairs, over packaging may mean there is an opportunity to reduce costs and materials by redeveloping a more efficient packaging design.
Expected Results: Working with Experienced Testing Partners
Whereas some manufacturers may choose to perform packaging testing internally, businesses both large and small have realized the benefit of outsourcing package testing. By working with an experienced partner, businesses can access packaging testing facilities and professionals when they need them without the overhead associated with such services. Most importantly, a packaging testing partner with a thorough understanding of packaging material performance, packaging design and package testing can eliminate costly rework, redesign and multiple rounds of testing.
Matt Thompson is Director of Packaging & Technical Services - Sealed Air Global Cushioning Solutions. To find a list of ISTA certified testing facilities, please visit www.ista.org orwww.sealedairprotects.com for a list of Sealed Air PDDC located worldwide.