Written By Ryan Hauser – Laboratory Analyst I
Distribution testing for ASTM D4169 encompasses a variety of different schedules, each aimed to target a different hazard or environment that a product-package system may encounter during its lifecycle. Some hazards are fairly straightforward within the distribution cycle, such as drops to simulate impacts. However, determining which hazards are applicable for a given package system may be more challenging when it comes to the different vibration testing schedules.
ASTM D4169 distribution testing includes several different Distribution Cycles (DC) intended to simulate different package configurations and anticipated variables that may be experienced via different modes of transportation. Distribution Cycles, in turn, are composed of a sequence of Test Schedules. Vibration-related schedules that can be applicable include Schedule D, Schedule E, and Schedule F, each intended to simulate a certain type of vibratory impact. Many distribution cycles include pre-defined vibration schedules. However, in the case of DC 2, which is intended as a build-your-own distribution cycle, as well as some other distribution cycles that may accommodate a few different package formats, end-users must choose which vibration schedules are appropriate to apply.
As such, it is important to be aware of the purposes that each of these distribution schedules serve, what they are intended to simulate, and which distribution schedule(s) is appropriate for evaluation of a given product-package configuration, or packout.
What is the Difference Between ASTM D4169 Vibration Schedules?
To understand the appropriate vibration schedule, it is first important to understand the specific distribution environment and hazard each schedule intends to represent. While all are vibration-related schedules, all vary in severity and are intended to evaluate different conditions a product-package system may experience. Knowing what each schedule reflects is important in understanding ASTM Distribution testing.
Schedule D – Stacked Vibration
Schedule D is stacked vibration, intended to evaluate the effect of vibration on a shipping unit while under compression resulting from the weight of other packages. During distribution, packages may be stacked, resulting in packages towards the bottom being subjected to the weight of packages above them. Schedule D incorporates this into the vibration test to evaluate the performance of a product-package system by subjecting it to vibration while also under the compressive forces of stacking. As such, Schedule D is especially relevant when anticipated distribution involves stacked shipping units.
Schedule E – Vehicle Vibration
Schedule E is vehicle vibration, intended to evaluate the effect of vibration during transportation in a vehicle. Unlike Schedule D, Schedule E focuses on the actual environment experienced by a product-package system during transportation. With its use of random vibration, this schedule can reflect the types of vibration encountered in various modes of transportation such as truck, air, and rail. As such, Schedule E is applicable to any product-package systems that undergo shipments via road or other applicable vehicle-based transportation modes.
Schedule F – Loose Load Vibration
Schedule F is loose load vibration, intended to address the effect of packages subjected to repetitive impacts during transportation. Rather than continuous vibration environments used in Schedule E, Schedule F is intended to evaluate the effect of repeated shocks that can occur when packages move and impact surfaces or one another during shipping. This testing is very relevant for distribution where packages are not palletized or maintained in a stable configuration throughout transportation and handling.
Comparison of ASTM D4169 Schedule D vs. E vs. F
| Schedule | Primary Situation/Environment | Primary Hazard |
|---|---|---|
| D – Stacked Vibration | Stacked shipping units | Vibration while subjected to stacking/compressive load |
| E – Vehicle Vibration | Vehicle transportation | Transportation induced vibration |
| F – Loose Load Vibration | Loose load distribution | Repetitive shocks/impacts between shipping units |
How Do You Determine Which Vibration Schedule to Use?
As defined above, in certain scenarios, specific vibration schedules must be chosen by the end user and incorporated into the Distribution Cycle. When determining which ASTM D4169 vibration schedule is appropriate, the biggest consideration should be the actual environment that the product-package system is going to experience. Some questions that can help establish an appropriate testing approach include:
- What configuration will this product-package system be shipped in? Will it be palletized, stacked, or transported as loose loads?
- What modes of transport will be used? Will the product be transported by truck, rail, air, or a combination of these?
- Will the package remain in a stable configuration throughout distribution?
- What distribution cycle is being used?
Selecting the Appropriate Vibration Schedules
Ultimately, selecting the appropriate vibration schedule for ASTM D4169 testing requires an understanding of the distribution environment and the hazards the product-package system will encounter. Schedule D addresses stacked vibration, Schedule E addresses vehicle vibration, and Schedule F addresses loose-load vibration. Since these schedules represent varying distribution conditions rather than simply levels of vibration severity, the appropriate schedule, or schedules, should be determined with the selected Distribution Cycle and the intended distribution environment.
When the expected distribution conditions are unclear, consulting with a qualified package testing laboratory can help to establish an appropriate and viable testing approach for your product-package system.