Coolant Safe High-Load Dunnage

I need a custom dunnage block engineered that can live permanently in coolant without swelling, cracking, or softening and still support up to 90,000 lb. The footprint has to stay close to 2 ft × 4 ft so it drops straight into our existing material-handling cradles.

Material preference: molded or machined Polypropylene for the main body. I chose PP because we have long exposure to water-soluble and straight-oil coolants; HDPE swells a bit for us and PVC is too brittle. Internally, I want a hollow-section design to shave unnecessary weight and cost while keeping the outer walls thick enough to handle the compressive load.

On the underside I need bonded or mechanically-locked strips of Nitrile rubber so the block will not skate around on steel skids or machine tables when a forklift sets a load on it. The rubber only has to cover the contact pads, not the full bottom face, as long as it stops lateral movement when the floor is wet with coolant.

Key acceptance points
• Static load test to 90,000 lb with less than 1 mm permanent deflection
• No measurable dimensional change after 72 hr submersion in our coolant (details supplied after award)
• Rubber stays attached after multiple forklift impacts and one full chemical wash cycle

Deliverables
1. Production-ready 3D CAD (STEP or SolidWorks preferred) of the hollow PP body and rubber inserts
2. Simple FEA or hand-calc summary proving the load rating
3. Manufacturing notes that specify resin grade, wall thickness, and recommended molding or machining process

If you already have experience designing heavy-duty pallets, dunnage, or chemical-service components, let me know—links to similar projects will move you to the front of the line.