The Instapak and similar expanding foam systems are great if they're used correctly. In my previous job, we were a distribution partner for a German company that made rack-mount RF generators; they were typically 2U or 3U enclosures that were perhaps 20" deep (~50 cm), and they weighed in at 15-20 kg (a WAG; it's been twelve years since I worked there). Initially, they would send them packed in heavy cartons with rubbery foam (think that multi-colored carpet padding stuff that looks like tiny chunks of assorted colors melded together) corners - a square piece about 2" thick and 6" x 6", with another 'L' shaped piece on top; the 'L' would be 2" wide and 1.5-2" tall. When glued onto the square piece, you'd get a 4" square flat pad with a 2" thick wall atop it. One went into each corner of the box, then the instrument went in. It sat on the 4" square pads, and was held away from the carton walls by the 'L'. Another set would go in on top, but facing down, giving you a generator held in place in all six corners.
This worked near perfectly, things rarely if ever suffered shipping damage.
Then they got an Instapak system. Line the box, squirt in the foam, put the cover sheet on, put the generator into the box, repeat the process for the top pad. Total disaster - nearly every generator that came in had bent rack ears and was bouncing around in the box. The thing was, the Instapak was fine for the top and bottom, where the mass of the generator was spread out over the large surface area, but failed miserably at the sides and corners. Two things worked against it - the first being that the foam at its best wasn't up for the concentrated force applied when the mass of the generator was applied though the much smaller surface area of the sides, front and rear vs the top and bottom, and the second being that because the two halves of the foam pillows met roughly mid way up the side of the generator, there was incomplete fill at that area, further reducing the ability of the material to hold up to forces resulting from shipping. We went from near 100% safe transport to damned near 100% needing body work upon arrival; the biggest thing being bent rack ears. The rack ears were, of course, an extension of the front panel material rather than add-on pieces of extrusion, so if the panel was damaged beyond the point where I could straighten the ears without it looking too much like a dog's dinner, I'd need to swap in a replacement piece of sheet metal. ROYAL PITA. Despite my pleas, they continued to use that system. Once I'd fixed the damaged generators, I'd squash down the foam at the sides and put an L shaped piece of Ethafoam in each corner (sort of like the OLD way) and they'd be fine. If they'd have put Ethafoam Ls in with the Instapak at the factory, things would have been fine, but that never happened. Horses for courses.
That said, I'll add my endorsement of AllTest knowing their way around packaging - in my experience, too, they have always done an excellent job of it.
-Pat
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Topic: Test Equipment Anonymous (TEA) group therapy thread (Read 17737161 times)