Suppose I want to ship my product via UPS, or whatever other professional carrier service. What vibration and shock forces should I design my product to withstand? And how can I effectively test my product against those forces?
UPS has, or at least had when I was transit testing packaged products, a specific packaging test standard based on ISTA standards and ASTM D4169. There's also a MIL-STD, 810 something, but I don't remember the exact number.
Typically, for a parcel carrier, the test, regardless of standard, consists of environmental conditioning, a "10 pt" drop test and a vibration test.
The environmental conditioning typically represents the extremes of what would be expected. In our case, we conditioned products for 12h @ +150F and -30F with uncontrolled humidity. The referenced standards discuss other conditions such as a high humidity environment.
The height of the drop is determined by the packaged weight. The product is dropped onto a rigid surface without inducing any vertical motion as follows:
- The bottom vertex of the carton which includes the carton seam.
- Each of the three edges radiating from that vertex.
- Flat on each of the 6 faces
Following that, the product is subjected to random vibration (typically 0.52 gRMS) for 1 hour on each of the three axes with a vibration profile according to ASTM D4728, ISTA or a profile developed from data collected by monitoring your particular distribution stream.
As to what forces you design your product to withstand dependent on a lot of things, mainly what's the cost of product breakage? What are the specific stages of getting your product to the customer? How much does it weigh? and so on. How much engineering and money are you willing to put into the packaging to protect the product? Can you make the product itself robust to transportation, or is it delicate and requires significant packaging? Like most engineering undertakings, it's a tradeoff and there's no one good answer that applies to all products. I recommend looking at the referenced standards, and using those as a guide.
If you want to get testing done without buying a test lab of equipment, there are plenty of labs across the country that will help you develop a test plan and perform the testing. I have personal experience working with Lansmont, they make packaging test equipment, perform testing in house and provide consulting on packaging design. (Note: My relationship with Lansmont is strictly as a prior customer, I have no personal, financial or other ties to them). They are great to work with. UPS also has a test lab and provides packaging design support.
I could go on and on about this stuff, but this is already long enough. If you have more questions, want further information or clarifications, I'll be glad to answer them.
When I have received fragile content in the past it has always come with a Shockwatch label attached to the side. I'm not 100% sure, but I believe there is some sort of guarantee by the shipper to keep the forces below the level registered by the label (a guarantee which most certainly comes at added cost). Looking up the specs in the link above, these labels activate if the shock parameters are above:
- Force: 25-100 G
- Duration: 0.5-50 ms
- Tolerance: $\pm$15%
These ranges indicate the range of labels available and the tolerance indicates the tolerance once you choose a set of parameters. If you can design the packaging to handle 100 G for 50 ms, then you should be in the clear.