Benchmark’s Vibsorb MIL-C-882 pad is a fabric-reinforced (cotton duck) elastomeric bearing pad, stocked in Canada and cut to size in 2–3 days. Expedited service is available.
A cotton duck bearing pad — also called a fabric bearing, preformed fabric bearing or fabric-reinforced elastomeric pad — is made from many thin layers of elastomer reinforced with closely spaced plies of cotton duck fabric, bonded into one solid pad. The fabric restrains the elastomer from bulging, so the pad carries far higher compressive stress than a plain neoprene pad, with low creep. A PTFE and stainless steel sliding surface can be added for larger movements.
Rating and design guidance: the MIL-C-882 pad is rated for compressive loads up to 10,000 psi. As a general design guide, plain cotton duck pads are best suited where relative rotation is no more than 0.003 radians and design compressive stress is no more than 2,500 psi. Where movement must be accommodated, use a PTFE/stainless sliding surface rather than shear of the fabric pad.
All above specifications are meant to be used for basic comparison and information purposes only. Please verify with the above manufacturers directly.
In order to have been selected for this list the above mentioned products would be considered to be of the highest quality. When engineers specify vibration control or thermal break products or brands they generally add the “or approved equivalent” option. Typically lead time and pricing become determining factors once the engineer on record has verified the selected product meets the design criteria.
Benchmark makes no further representations.
Vibsorb structural expansion bearings, or slide bearings, accommodate thermal expansion and structural rotation in buildings, bridges and pipe supports. They are supplied as an upper and lower unit prepared to be tack or stitch welded in the field. See PTFE slide bearings for all sliding bearing options.
VIBSORB type expansion bearings are used when construction tolerances, high load, and rotation are prominent with beam spans being excessive. This bearing is the most resilient in our full line of expansion bearings.
VIBSORB type slide bearings are used when construction tolerances and loads are moderate. This bearing has a very low coefficient of friction which is exceptional for use where expansion is large.
VIBSORB type slide bearings are used as well when construction tolerances and loads are moderate. This bearing has a higher coefficient of friction than the VIBSORB expansion Bearing and is used where the expansion criterion is limited.
VIBSORB slide bearings can be made with holes and slots, if required, to allow for mechanical attachment of expansion units to steel structures or for anchoring to concrete structures.
Benchmark also offers VIBSORB type expansion bearings made with graphite to achieve effective performance in high temperature environments.
Contact us to discuss your project requirements and schedule.
| Pad type | Best for |
|---|---|
| Cotton duck (fabric-reinforced) | Very high compressive loads, low creep, limited rotation: heavy steel and precast beam seats, crane rails, equipment |
| Plain neoprene | Lighter loads where the pad must take more shear movement and rotation |
| Random-fiber | Precast concrete beams, double tees and hollow-core at moderate loads |
| Shimmed (steel-laminated) | Bridge girders with larger movements and rotations |
Yes. “Cotton duck” refers to the woven cotton fabric used as reinforcement, so cotton duck pad, fabric-reinforced pad and fabric bearing are used interchangeably.
When bearing stresses are high and creep must be kept low. Plain neoprene is softer and better where the pad itself must take more movement.
Yes — any size or shape, with holes and slots, typically in 2–3 days from Canadian stock.