Application Guide: Friction Brake System
Products
BACKGROUND
Brake systems (disc or drum) work to directly oppose a vehicle’s tendency to move. Friction
materials in brake systems include clutch facings, linings, blocks, and disc pads. These are
typically made from a mix of fibers, fillers, lubricants, resins and abrasives. Historically, fibers
from asbestos were used due to superior reinforcement and heat resistance properties. In
recent years, this mineral has been replaced by less hazardous alternatives such as
wollastonite, mineral wool and glass fibers.
Important goals in friction systems include noise control, improved rotor and drum wear,
vibration control, and product life improvement.
EXPECTED OBSERVATIONS
Overall wear improvement with low noise, low vibration, and acceptable friction stability are
achieved when reinforcing fillers are utilized.
In some systems, melting of milled glass may be a concern. The suggested replacements are
wollastonite or mineral wool or a combination.
Selection of appropriate surface treatments can improve wettability and bonding.
COMMENTARY
Friction material formulations are complex and performance can vary. Each application should
be carefully examined and selection should be based on formulation and prototype definition
and performance.
