packer, ever thought about getting ahold of a kitchen / bakery rack?
Steel racks for sheetpans that are used from everything from plated salads to being loaded with dough and shoved into a conveyor oven.
Depending on cost, might be a good option for bulk production. They take quite a beating. (Imagine running a kitchen with perpetually high dishwashers and a long staircase - the racks do well with bouncing, the the dishes don't.)
Sturdy, easy to clean / sterilize, wheeled for easy movement, overkill in terms of weight/abuse you'd put on them, also cheap from restaraunts going out of business. You could hit these things with a truck or golf cart at low speed (don't ask) and still bend them back into shape a few times before they'd stress crack. For containment, using tupperware / plastic lined box underneath would likely suffice.
^_^