Kevin Howard, a packaging engineer from Packnomics, was kind enough to share his experiences regarding the protection of electro-mechanical products.
The rest of this article was written by Kevin.
My background is distribution packaging and testing, but these fields reach right into the product design space, especially for electromechanical products since there’s a direct tradeoff between product fragility and the amount of protective packaging required to survive distribution hazards.
The following thoughts are mostly derived from my work on electro-mechanical products, but may apply to many other manufactured products as well:
1. Why testing is essential — for product protection but also for cutting costs
Each and every component of a product should be well defined and specified. The manufacturer of these components should be able to prove they have employed the correct materials, that it’s sized correctly, and that it meets some kind of performance level(s).
Performance levels are different than material specs since they can quantitatively provide insights to the combination of materials employed and manufacturing quality. For instance, a correct paint may be applied and yet scuff off of a surface easily if the paint is mis-applied. Similarly, a box material may appear to be correct, but if the score lines are not set correctly and sub-par glue is used to hold it together, the box will fail.
A performance test is often easier to conduct than material tests and yet divulge potentially more pertinent information.
For instance, it takes lots of time and special equipment to dissect corrugated box material and attempt to measure the basis weight of each layer of paper used, measure the edge crush value of a small rectangular sample, and measure the burst value of a small sample.
In contrast, a compression test of the completed box immediately defines whether or not the combination of materials and manufacturing quality meet the minimum strength required to survive distribution. This kind of test is easily run and provides not only the essential information of whether the box meets a minimum standard, but also tells how much design margin is provided.
I have come across many examples where the user hadn’t realized their boxes were 2-5 times stronger than required, thus wasting lots of money with no apparent return.
2. When to test the product’s resistance
Many of the electro-mechanical products I’ve worked on have hundreds, if not thousands, of components. A valuable performance test for such products is a simple drop test, both for the bare product and for the packaged product.
Impact tests can be something as simple as dropping from a certain height onto a stiff surface (best to define this surface!), or using a more sophisticated method like a shock table, where one controls the input shock and the orientation of the product or package during that shock, though such equipment is fairly expensive.
If one knows that the bare product sustains no damage from some height at the beginning of production, then products in future runs should also demonstrate that level of ruggedness. If something breaks from an impact sooner than what the originally-approved product withstood, then it becomes clear very quickly that either a component or the assembly process has changed.
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Kevin’s other articles are listed below: