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Major Performance Properties of Ideal Friction Material

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in the range of 0.35-0.45 depending on the type of vehicles

Low fade & high recovery of the Least sensitivity of to load & speed, humidity,

water, oils, brake-fluids, temperature etc.Moderately low wearGood conformability and compatibility with the rotorResistance to low frequency vibrations & squealing

noiseHigh thermal stabilityEco-friendliness etc.

Categories of FM

Resin

Fibers

Space fillers

Functional fillers

(to improve some special properties such as friction, wear

resistance, TC, processibility etc)

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Points to consider for the design of experiment

S.no

Properties Remarks.

1 Specific Gravity Weight of Caliper increases and may cause Judder during Braking

2 Hardness Low hardness may cause faster wear rate of the pads.

3 Heat Swell Higher Heat swell value may affect severe Braking at high speed.

4 Bonding Shear Strength

Higher bonding strength is better for high speed driving of the vehicle

5 Friction as per SAE-J661 Equivalent to IS-2742

Higher friction level is good, for achieving minimum stopping distance at higher speed of the vehicle.

6 Wear Loss Lower the wear loss higher the life of the pads.

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Ingredients Properties

Fibers

Steel wool Good wear resistant raw materials

Copper chipsPoor wear resistant but used for enhancing friction

Fillers

Graphite good wear resistant raw materials because of their good wear resistant capability.Zircosil

BarytesPoor wear resistant but used for enhancing friction

Nitrile Butadiene Rubber

a good toughened rubber for the organic binder and has a positive effect to improve wear

Binder

Phenolic ResinTo bind the rest of the ingredients in the formulation

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MIXING

PRE-FORMING

CURING

POST-CURING

FINISHING

FORMULATION WEIGHT BULK DENSITY

COMPACTNESS, UNIFORM LEVELLING,

CORRECT WEIGHT

TEMPERATURE, PRESSURE, VENT CYCLE

TEMPERATURE & TIME CYCLE

CONFORMANCE TO PDS

DEVELOPMENT OF BRAKE PAD( METHODOLOGY)

MEASURING FRICTION AND WEARTESTING

Parent composition Selected Resin

Compression molding

T = 160°C P = 17 to 21

MpaTime = 6 min.

Post curingTemp 120-

160°C for 8 hrs

FinalFinal productproduct

Plough Type Shear MixerChopper Speed-2800 RPM

Feeder RPM – 140

Preparation of Brake Pads

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Cavity filled with powder

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Preform pressure = 170 Kg/cm2

Job after Preforming

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Pressure = 17 Mpa

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 Post CuringCycle 1 - 200° C - 205°C – 2 hrs

Cycle 2 – 240°C – 245°C – 3.5 hrs.

Properties tested as per IS 2742 standardsS.N

oProperties Unit

Final formulation

O.E brake pad

1 Specific Gravity - 2.54 2.602 Hardness HR S 95 903 Acetone Extract % 2.05 2.16

4 Heat Swell In mm 0.14 0.12

5 Loss on Ignition at 800o C % 24.86 20.45

6 Cold Shear Kg/

Sq.cm42 45

7Hot Shear Test @ 200 C / 45 Minutes

Kg/Sq.cm

27 30

8Co-efficient of Friction as per SAE J -661a

Normal Mue

0.460 0.495

9Co-efficient of Friction as per SAE J -661a

Hot Mue

0.400 0.460

10 Wear % 4.2 2.5 12

Effect of Fiber Orientation

10 degrees off y axis

Modulus Based on Fiber Angle