“Quality means doing it right when no one is looking “All good work requires self-motivation of labor.” "Quality is everyone's responsibility.” “Quality is not act. It is a habit.” "Do it right for the first time."

Quality Policy:

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Our pledge is to provide the market with the best quality products, who meet international quality standard at competitive prices through dynamic management team.

Quality Standards:

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RAINBOW Rubber Industry is producing Elastomeric Bridge Bearings in accordance to meet with all of the following International Standards such as (American AASHTO M251, European EN1337-3, British BS 5400, Italian CNR 10018, German DIN 4141, French SETRA B.T.4, Korean KS 4420 etc. The elastomer used in the moulding process can be Polychloroprene CR (also called Neoprene), Natural Rubber (NR) or Styrene Butadiene Rubber (SBR) depending on specification requested.

Our Quality Assurance:

Rainbow Rubber Industry prides itself on having over 50 years experience in manufacturing constructional, Automobile Sea Marine rubber products. Rainbow Elastomeric Bearings Pads have been tried and tested under demanding traffic conditions and have a long life-span. They have been used successfully around the world for more than 50 years

Qualified personnel, up-to-date production lines, testing laboratories, and quality control at every stage of the manufacturing process, gives us the guaranteed high quality of elastomeric products.

Rainbow Rubber Industry, have our own bearing testing machines which can bear up to Vertical load of 4200 KN with horizontal shear load up to 400kN and movement up to 100mm for the different bearing pads and expansion joints.

Mouldings of RAINBOW Bearing Pads are done on fully automatic CNC compression moulding machines with vacuum system which insures no air entrapment inside the Bearing Rubber Pad.

All the operations such as shot Blasting, Galvanizing, Bounding of steel plates, moulding, tooling and mechanical testing is being done by highly skilled and technical manpower.


Rainbow Rubber Industry recognizes the importance of reliability that’s why our staff members are focused on ensuring that the products supplied to our customers is right for the first time.This equates to the right product, to the right specification, and the right price. Because if it will be the Rainbow Rubber Industry product, you know the quality is right and the performance is guaranteed. Because we know one thing that:


As per the RAINBOW philosophy, fully equipped in house design & development, manufacturing and testing facilities for stage inspection and quality control have been established.

With a State-of-Art testing laboratory for rubber/polymer consisting of Tensile Testing (UTM), Rheometer (MDR), Hardness tester (Dura A), Profile Projector, Specific Gravity, Accelerated Ageing Ovens, quality of the product is always ensured in RAINBOW Products.

Compound is tested for physical properties as per international standards in the test lab.

Materials and Loads:

The elastomer is a macromolecular material which demonstrates considerable deformation at low load and which returns to its initial size and shape when this load is removed.

Rainbow Elastomeric Bearing Pads are available in synthetic neoprene-chloroprene rubber (CR) or in the more economic natural rubber (NR) with ozone level upto“0”.

The material specification for the Rainbow Elastomeric Bearing Pads shall meet the requirements of the current Shell conform to section 18 “Division – II” of according to AASHTO M251 specification 2006 for Highway Bridges standard.(Standard specifications for Plain / laminated elastomeric bridge bearings) as listed under subsections “Materials” and “Test”.

The Rainbow Elastomeric Bearings functions primarily as an elastic, load transmitting link between construction elements which need to be connected in such a way as to allow a degree of movement. Vertical loads from the structure itself and traffic loads are transmitted without constraint into the bearing seat. Acceleration and deceleration forces from traffic load, wind forces and centrifugal forces are also efficiently absorbed by the bearings, as well as forces arising from skewed movements of adjacent structural elements.

The materials used and the structural composition of the bearings mean that they are able to accommodate movements resulting from temperature differences between construction elements. Rotational forces from the skewed arrangement of structural components are absorbed by elastic deformation around two horizontal axes.

Vertical Loads:

Loadings shown in the table are the maximum recommended working loads. At these loads a deflection of up to 15% of the initial pad height could be expected. As these pads are not bonded to the mating surfaces, the actual deflection is determined by the frictional characteristic of the contact surfaces. Care should be taken as holes or cut outs in the elastomeric bearing pads/strips may have a substantial effect by reducing the load carrying capacity and increasing the deflection of the pad or strip.

Shear Deflection/Stiffness:

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The allowable shear deformation is normally in the order of 30% to 50% of the compressed pad/strip thickness from the neutral position. Shear deflections of up to 70% may be considered but careful consideration must take of possible slippage due to the frictional coefficient of the rubber to structure mating surfaces.


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Tilting of the load bearing surfaces relative to each other causes a “rotation” of the elastomeric bearing pad/strip. The basic limiting criterion is that no gap occurs between the structure and the pad/strip. The rotational capacity tables include the 0.0035 radians that should be allowed to accommodate design tolerances.


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The non-reinforced Rainbow Elastomeric Bearing will “spread” in surface contact area when under load. The amount of “spread” is largely determined by the frictional coefficients of the structures surfaces mating with the elastomeric bearing pad/strip. It is important to allow clearances around the elastomeric bearing pad/strip to allow for this slippage once the structures weight is imposed on the elastomeric pad/strip.


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The Rainbow Elastomeric Bearings shall be composed of multiple laminates of elastomeric material separated by galvanized steel reinforcing. Bearings have steel plates as the reinforcement shall be cast as a unit in a mold under pressure and heat and the steel plates separating the elastomeric layers shall be completely bonded by vulcanization to the elastomeric material on all surfaces. An external load bearing steel plates(s) shall be factory vulcanized to the elastomeric bearings during the primary molding process.

Test Equipment:

• Tensile Test Machine

• Oscillating die Rheometer

• Hardness Tester

• Compression set apparatus - deflection

• Specific Gravity Balance

• Thickness Gauge : 5mm and 25mm range

• Hot air Oven (250°C)

Following tests can be performed at our laboratory

• Hardness

• Compression Set

• Tensile Strength

• Bonding Strength

• Elongation at break

• Tear Strength

• Load V/S Deflection test

• Ozone Resistance 100pphm/100hrs

• Aging Test