Types of Distribution Testing
Impact - This test evaluates the ability of a package to handle and protect the product against collisions that occur in the distribution environment. Whether the package is dropped, knocked or simply banged around, the impact can cause product damage. To conduct an impact test, the package is allowed to freefall onto corners, edges, and flat surfaces. Many test procedures conduct all of the impacts from the same drop height regardless of orientation.
Impact testing isn’t limited to just packages; often the products themselves need to survive the in-use environment which can be more severe than the distribution environment. Think about how many times you drop electronic items such as cell phones, remote controls, radios, handheld meters, etc. Every incident can impact the life of that product.
Compression - Compression testing is conducted for a variety of different reasons, most of which involve determining the top load capability of materials or systems, primarily packages. The goal of the test is to determine the maximum safe load that the packages or other system components can withstand.
Compression testing is a key element in determining package and product design verification and quality control. Two procedures are common. One is a test to failure (ASTM D642) while the other determines if an anticipated load can be safely applied.
Vibration - This refers to the ability to replicate the vehicle excitation that occurs in the real world to your product/package systems in order to witness the effects and identify weaknesses. Vibration occurs in all forms of transportation and at varying levels of intensity in the distribution environment. In the real world, vibration is complex and can intensify the natural frequencies within a product/package system. The cushioning of a package system also has a natural frequency. If the natural frequency of the product and the package coincide, damage is likely to occur. Most so-called “hidden damage” during transit is likely caused by compound resonance.
Altitude - This simulates the reduced air pressure experienced at higher elevations and the impact on the integrity of the sealed package. Sealed flexible systems have the potential to fail when exposed to altitude. In fact, altitude exposure by truck transport can exceed the levels experienced in commercial air transportation.
An altitude test is either a pass or fail. Pouches, for example, may burst at the seams if the internal pressure of the flexible packaging cannot equalize. Additional packaging costs may be incurred to pull a partial or full vacuum on the packaging in order to avoid the effects of altitude. Altitude can also affect your product when the package is jeopardized.
Loose-Load - Also called “Bounce Testing” and “Fixed Displacement Vibration,” this test was conceived in the early days of package testing in an attempt to duplicate the negative effects of vehicle vibration, primarily over the truck road. The apparatus consists of a horizontal platform mounted on an offset cam that results in circular synchronous motion when viewed from the side of the platform. The cam mount is driven by a variable speed motor and the displacement is fixed at one inch peak-peak.
To conduct the test, the package under test is placed on the platform. The speed of rotation of the drive is increased slowly until the package leaves the surface of the platform by a small amount. This speed is maintained for the duration of the test which is typically 15 to 60 minutes.