Technical Specifications

1. Material Composition

 

 

Component	Percentage (Approx.)	Function
Rubber Binder	Primary matrix	Structural bonding, impact absorption
Phenolic Resin	1 – 10% by weight	Strengthening, thermal stability
Aramid Polymer Fibers	Minor proportion	Wear resistance, reinforcement
Friction Modifiers	Up to 15% by volume	Coefficient of friction control
Mineral Fillers	Variable	Friction promotion, thermal management
Vulcanizing Catalysts	1 – 3% by weight	Rubber curing acceleration

2. Manufacturing Process

 

 

Step	Description
1. Raw Material Blending	Precise weighing and mixing of rubber binders, aramid fibers, fillers, and resin components
2. Cold Molding	Rigid cold molding process to form the pad shape
3. Compression Molding	Injection or compression molding at controlled temperature and pressure
4. Thermal Curing	Vulcanization of rubber matrix and polymerization of phenolic resin
5. Post-Cure Processing	Controlled cooling and conditioning to achieve final properties
6. Quality Inspection	Dimensional check, hardness, density, and friction coefficient verification

3. Physical Properties

 

 

Property	Value
Density	2.40 – 2.70 g/cm³
Hardness (HRX)	24 – 45
Cross Breaking Strength	≥100 kg/cm²
Shear Strength	≥8.0 KN
Compression Modulus	1000 – 3000 N/mm²
Acetone Extract	≤3.0%
Loss on Ignition	≤15%

4. Friction Performance

 

 

Parameter	Specification
Classification	High Friction Composition (H-Type)
Average COF (Dry)	0.35 – 0.45 μ
Average COF (Wet)	0.27 – 0.35 μ
AAR Light Braking COF	≥0.32
AAR Heavy Braking COF	≥0.27
Static COF	≥0.38

5. Operating Specifications

 

 

Parameter	Specification
Maximum Operating Temperature	400°C
Peak Temperature	500°C
Maximum Brake Force on Disc	5.0 Tons
Suitable Speed Range	Up to 200 km/h

Maintenance Guidelines

Proper maintenance of AAR standard composite brake pads is essential for ensuring safe and reliable braking performance. Follow these guidelines to maximize service life and maintain operational safety .

1. Periodic Inspection

Inspection Frequency: Conduct visual inspections at regularly scheduled maintenance intervals per APTA RT-VIM-S-007-02 guidelines .

Visual Inspection Checklist:

• Check brake pad wear: new pad thickness is 35 mm, minimum allowable thickness is 7 mm 

• Inspect for cracks, damage, or missing components 

• Look for foreign objects embedded in the friction surface

• Check for oil or grease contamination on pad surface

• Inspect pad holders for play and proper seating 

• Check for presence of dust or greasy material on calipers and actuators 

2. Wear Monitoring

Wear Limit Indicators:

• Brake pads should incorporate wear indicators or matchmarks to determine the minimum permissible thickness for replacement 

• Replace pads when thickness reaches 7 mm minimum 

• If one pad is worn out, replace in full set formation (all pads on the axle) 

Monitoring Notes:

• Monitor play of brake pads in holders

• Visual check should include both pad surface and backing plate condition

• Document wear measurements at each inspection interval

3. Cleaning and Contamination Control

Recommended Practices:

• Remove dust and greasy material sticking to brake calipers and actuators with suitable tools 

• Ensure no lubricant drops on brake discs 

• Keep friction surfaces clean and free from contaminants

• Do not use solvents that may degrade the composite material

Precautions:

• Avoid contact with petroleum-based solvents

• Do not attempt to clean pads by sanding or grinding – replace if contaminated

• Store pads in clean, dry environment away from oil and grease

4. Replacement Procedures

When to Replace:

• Wear limit reached (7 mm minimum thickness) 

• Cracks or visible damage detected

• Contamination that cannot be removed

• Uneven wear patterns indicating misalignment

Replacement Guidelines:

• Always replace pads in full sets per axle 

• Clean pad holders and calipers before installing new pads

• Ensure proper seating of new pads in holders

• Check pad play after installation

• Perform brake function test after replacement

5. Storage and Handling

 

 

Storage Condition	Requirement
Temperature	Ambient (0°C – 40°C)
Humidity	Dry environment, avoid moisture
Contamination Prevention	Protect from oil, grease, and solvents
Shelf Life	Consult manufacturer's recommendation
Stacking	Do not stack excessively; store on clean, flat surfaces

6. Safety Precautions

• Always follow established lock-out/tag-out procedures when working on brake systems

• Wear appropriate PPE (gloves, eye protection)

• Do not inhale dust from worn brake pads

• Dispose of used pads in accordance with local environmental regulations