Brake pads manufacturing

Brake pads are a vital part of any vehicle's braking system. They provide the friction that slows the vehicle's braking and prevents the wheels from spinning. Brake pads are made of various materials and when pressed against the brake disc, they create enough friction to convert the vehicle's kinetic energy into heat energy. This heat energy is then dissipated by the braking system.

BRAKE PADS

Brake pads sit between the rotor and caliper to reduce metal-to-metal friction.

BRAKE PADS

Brake pads are the materials that sit between the brake caliper and brake rotor in a disc brake system.

BRAKE PADS

Brake pads are made of friction material and press against the rotor to slow down and stop the vehicle.

BRAKE PADS

Proper brake pads can mean the difference between your vehicle hitting an object or being able to stop quickly before hitting an object.

Brake pads serve an important safety purpose in vehicles. Without properly functioning brake pads, drivers cannot stop their vehicles in a safe and controlled manner. As a result, vehicles cannot stop at stop signs and traffic lights. They can also prevent a vehicle from slowing down when necessary to avoid a collision. Properly manufactured and properly maintained brake pads are essential for the safe operation of every vehicle on the road.

BRAKE PADS

Brake pads sit between the rotor and caliper to reduce metal-to-metal friction.

BRAKE PADS

Brake pads are the materials that sit between the brake caliper and brake rotor in a disc brake system.

BRAKE PADS

Brake pads are made of friction material and press against the rotor to slow down and stop the vehicle.

BRAKE PADS

Proper brake pads can mean the difference between your vehicle hitting an object or being able to stop quickly before hitting an object.

Decades of improvements in brake pad materials and design have resulted in brake pads that are quieter, produce less brake dust, and are more durable. While the fundamentals of how brake pads function remain the same, advances in manufacturing processes and testing have improved the consistency and performance of modern brake pads. Understanding brake pad manufacturing processes, testing procedures, and application provides insight into this important automotive safety element.

Brake pads manufacturing

History of Brake Pads The history of brake pads dates back to the late 19th century, when the first modern friction brake pad material, Ferodo, was invented. This was a significant advance over the earlier leather brake pads.

Asbestos began to be used in brake pads in the early 20th century due to its excellent heat resistance. However, due to health reasons, the use of asbestos in brake pads was banned in most countries until the 1990s.

BRAKE PADS

Brake pads sit between the rotor and caliper to reduce metal-to-metal friction.

BRAKE PADS

Brake pads are the materials that sit between the brake caliper and brake rotor in a disc brake system.

BRAKE PADS

Brake pads are made of friction material and press against the rotor to slow down and stop the vehicle.

BRAKE PADS

Proper brake pads can mean the difference between your vehicle hitting an object or being able to stop quickly before hitting an object.

The development of new materials and compounds revolutionized brake pads in the mid-20th century. Ceramic compounds have improved performance and driven innovation in high-performance brake pads for racing applications.

BRAKE PADS

Brake pads sit between the rotor and caliper to reduce metal-to-metal friction.

BRAKE PADS

Brake pads are the materials that sit between the brake caliper and brake rotor in a disc brake system.

BRAKE PADS

Brake pads are made of friction material and press against the rotor to slow down and stop the vehicle.

BRAKE PADS

Proper brake pads can mean the difference between your vehicle hitting an object or being able to stop quickly before hitting an object.

More recently, attention has been focused on eco-friendly organic brake pads made from compounds such as rubber, Kevlar, fiberglass, and carbon fiber. These offer the same performance with a reduced environmental impact.

Key innovations include the development of new friction materials, improved heat dissipation, reduced noise, and optimized connections for different vehicle applications. Overall, brake pad technology has evolved significantly, from leather pads to high-tech materials for optimal stopping power.

Brake Pad Materials

Brake pads are made from a variety of friction materials and provide braking action by gripping the brake disc or drum. The most common materials used in modern brake pads are:

**Asbestos-Free Organic Materials (NAO)**

These brake pads use a mixture of fibers, fillers, resins, and binders that are not derived from asbestos. Common materials include glass, rubber, Kevlar, carbon, copper fibers, and organic or ceramic fillers bound with various resins. NAO pads offer reasonable braking performance and low noise, but tend to perform poorly at higher temperatures. They are the most commonly used replacement material on most vehicles. **Ceramic**

**Ceramic**

Ceramic brake pads contain ceramic fibers, fillers such as copper or graphite, binders, and little to no steel wool. They are more heat resistant and durable than NAO pads, but are usually noisier. Though more expensive, ceramic pads provide strong stopping power, are more resistant to fade, and allow for high-performance riding.

**Semi-metallic**

Semi-metallic pads use 40-65% steel or copper fibers bound with fillers and resins. They have higher friction and are more resistant to fade under hard braking, but they also produce more brake dust and are noisier. Semi-metallic brake pads are common in high-performance vehicles and heavy-duty applications.

**Sintered metal**

Sintered metal covers are made by bonding metallic materials such as copper, iron, and steel using high heat and pressure. They can withstand extreme temperatures, have high friction, and are durable. However, sintered metal coverings also produce noise and dust. They are most commonly used in racing and demanding braking applications. The choice of brake pad material requires a balance of stopping power, squeal, dust, fade resistance, durability, etc. Ceramic and semi-metallic pads offer the best stopping power and heat dissipation during aggressive driving, while NAO pads offer quieter everyday braking in normal driving conditions.

Brake Pads Manufacturing Process

The manufacturing of brake pads requires several steps to ensure quality control and meet safety standards. The main steps are outlined below:

Mixing

The friction material ingredients such as binders, fillers, fibers and abrasives are carefully weighed and mixed in an industrial mixer according to a formulated recipe. The mixing process aims to ensure that the ingredients are evenly distributed.

Preforming

The mixed raw materials are pressed into blocks of different sizes and shapes, depending on the desired brake pad design. This preforming step gives the compressed material its original shape.

Molding

The preformed blocks are then heated and formed into the final brake pad shape using hydraulic or mechanical presses and precision dies. High pressure is applied to contour and achieve the required density and surface finish.

Curing

After molding, the brake pads are subjected to a controlled heating or cooling cycle to cure the bonding resin. This curing process hardens the coating and determines its final properties. Temperature, duration and environmental parameters are precisely controlled.

Finishing

After curing, the brake pads go through several finishing operations, including trimming, chamfering, surface grinding and even application of an exterior or undercoat. This determines the final dimensions, surface finish and deck installation requirements.

Testing

Extensive testing is carried out on the finished brake pads at multiple stages to ensure they meet all specifications in terms of quality, performance, durability, noise etc. Standards bodies have detailed test protocols.

Quality Control

Automated inspection and quality control are carried out at various points in the manufacturing process to ensure consistency and prevent defects. All processes and materials are closely monitored.

Brake Pads Testing and Certification

Brake pads must meet stringent safety and performance standards before they are approved for use in a vehicle. Several important tests are performed:

*FMVSS 105**

This SAE standard specifies the minimum performance requirements for service braking systems in the United States. This includes stopping distance tests starting at 90 mph, thermal decay and recovery tests.

**FMVSS 135**

This standard specifies the requirements for brake systems in light motor vehicles. It covers topics such as brake fluid viscosity, corrosion resistance, temperature behavior, and hydrolytic stability.

**ISO 26867**

This international standard determines the coefficient of friction and wear rate of brake pads during dynamometer testing. Brake pads are tested at various speeds, pressures and temperatures.

**AK Master**

The AK Master test bench puts brake pads through temperature cycles, water submersion tests and various pressures to ensure their performance. It simulates real braking conditions.

**Noise Testing**

Brake pads are tested for squeal and noise levels in a special acoustic test chamber. A microphone records the frequency and decibel levels during a simulated braking process.

**Salt Spray Testing**

Brake pads are exposed to a salt spray chamber that creates a corrosive environment. This evaluates the corrosion resistance of the coating.

**Dust Testing**

Brake pads are tested for dust generation tendency. The amount and chemical composition of the generated dust are measured.

**Compound Testing**

Test vehicles are used to evaluate pavement materials under real road conditions. Braking distances, wear rates, noise, vibration and other criteria are measured over thousands of braking events.

Rigorous testing and certification ensures that our brake pads meet the highest safety, quality and durability standards before they are installed in your vehicle. Manufacturers invest significant resources into rigorous product validation procedures.

Automotive Applications

Brake pads are used in a variety of automobiles primarily for stopping or slowing. Major automotive applications include:

1- Passenger Cars: Most commonly found in passenger cars, SUVs, vans, and light trucks for passenger transport. Passenger car brake pads are typically made from semi-metallic or low-metallic compounds that balance braking performance, durability, noise, and cost.

2- Commercial Vehicles: Used in heavy vehicles such as large trucks, buses, and trailers where vehicle weights have increased and frequent braking under load requires more durable brake pads. Materials are typically semi-metallic and contain low levels of steel.

3- High Performance: Sports cars and racing vehicles use high friction formulas and modified compounds to maximize stopping power in extreme conditions, but this may come at the expense of longevity. Materials include ceramic, carbon fiber, Kevlar, and sintered metals.

4- Motorcycle: Motorcycle brake pads are suitable for high speeds, hard braking, wet conditions and different types of roads. Sintered metal compounds have high friction but low heat resistance. Organic materials provide a smoother snap.

5- Aviation: Aircraft brake pads must withstand high temperatures caused by hard braking. Carbon and sintered metal are common. Newer aircraft use carbon brakes, which are lighter and more durable.

6- Rail and public transport: Subways, trains and light rail systems use high friction, durable brake pads that work in dirty conditions. Metalloid and low-steel compounds are typically used. Asbestos-free organic materials are also common.

The correct choice of brake pads depends on the type of vehicle, operating conditions, performance requirements and other factors. During production, the focus is on developing a recipe that meets the needs of each application.

Brake Pad Maintenance and Repair

As part of the routine maintenance of your vehicle, your brake pads should be checked regularly and replaced if necessary. Most car manufacturers recommend inspecting your brake pads during oil changes and other routine maintenance. There are a few signs that your brake pads need replacing:

**Squealing or grinding noises**

- When braking. This indicates that the brake pad material has worn away in parts.

**Vibration or shuddering**

- Pressing against the steering wheel when braking. This may indicate uneven pad wear.

**Extended braking distance**

- Worn pads reduce the effectiveness of your brakes in slowing your vehicle.

- Brake pads are less than 2-3 mm **thickness**. Many brake pads have built-in wear indicators that will squeal when the brake pad material is nearly used up.

Typical brake pad replacement intervals are 30,000 to 70,000 miles, but vary depending on the make and model of your vehicle. Aggressive drivers will need new pads more frequently. Brake pads should always be replaced in axle sets.

Replacing brake pads involves:

- Lift the vehicle and remove the wheels.

- Remove the brake caliper assembly.

- Remove the old brake pads and all hardware.

- Install the new pads and hardware.

- Lubricate the necessary components.

- Reinstall the brake calipers.

New brake pads require a break-in period of several hundred miles to allow material to migrate to the rotor surface for maximum stopping power. Avoid hard braking for the first 200 miles. You can always find information about properly breaking in your brake pads in your vehicle's owner's manual.

Proper installation and maintenance of your brake pads is critical to safe and effective braking. Follow your vehicle manufacturer's recommended maintenance intervals and replace your pads before they are completely worn out.

Environmental Aspects

One of the biggest environmental issues with brake pads is the material they are made from. Older brake pads contained asbestos, a known carcinogen dangerous to human health. Fortunately, asbestos from brake pads has been banned in most countries. Modern covers use materials such as copper fibers, glass fibers, rubber compounds, and other less harmful man-made materials.

Brake pads produce dust containing tiny particles from the pad material that can pollute the air. Some of the compounds found in brake dust can be harmful to people and the environment in high levels. Proper disposal of used brake pads reduces environmental pollution.

Brake pads also contribute to noise pollution. The high-frequency squeal of brakes is not only annoying, but also increases noise levels, which can be harmful to human health. Manufacturers are constantly improving brake pad materials and washers to reduce brake noise. Ceramic and semi-metallic compounds produce less noise than the older organic covers.

When brake pads wear out, they generate waste that must be disposed of properly. Used pavement contains heavy metals and other compounds that can leach into soil and water if disposed of in landfills. Many manufacturers and repair shops now recycle used brake pads. The material can be recovered and used to manufacture new brake parts. Having a closed recycling cycle helps to minimize the impact of brake pads on the environment.

Upcoming Trends

The brake pad manufacturing industry will continue to evolve as new technologies emerge and regulations change. Some of the key trends to watch include:

**New Materials**

- Ceramic and semi-metallic materials are becoming increasingly popular as they offer superior braking performance and durability compared to organic pads. Manufacturers are constantly developing and improving these materials.

- Carbon fiber and carbon-ceramic composites are being researched as they can withstand high temperatures while reducing brake fade. These unusual materials may become more commercially viable initially in luxury vehicles.

- Nanotechnology and surface treatments can create coatings with improved properties. Expect continued improvements in friction materials as nanotechnology allows for better compositional control.

**Sensors and Telematics**

- Integrated sensors allow the brake pads themselves to monitor wear and transmit this data to the on-board computer and telematics system. This allows for proactive maintenance and replacement of parts.

- Intelligent braking systems integrate information about the vehicle load, speed, road conditions, and driving style to adjust braking in real time to optimize performance and lifespan.

**Electric Vehicles**

- As electric vehicles gain a larger market share, brake pads are being tailored to their specific braking needs. Regenerative braking systems absorb energy during braking, reducing brake pad wear.

**Autonomous Driving**

- Autonomous vehicles have different brake usage patterns than human drivers. Brake pads must be able to accommodate this gentle braking profile over long periods of continuous light use.