The brake pad is mainly composed of friction material, heat insulation layer, adhesive, back plate, muffler plate, and accessories.

1 Friction material

Friction material, also known as fabric, is the technical core of brake pads and directly determines the performance of brake pads. It is not composed of a single material, but is made by mixing and pressing more than 10 or even more than 20 different materials. According to different formulas, it can be divided into semi-metal formula, low metal formula and ceramic formula.

2 insulation layers

Some people also call the thermal insulation layer the bottom material, which is generally located at the bottom of the friction material and has a thickness of about 3 mm. When braking, the temperature of the friction material rises rapidly, and the continuous heat is transferred to the metal back plate, which is then transferred to the brake fluid through the piston, which may cause problems with the brake fluid. However, the primer is not necessary, this is related to the heat conduction of the friction material.

3 Adhesive

The brake pads can work stably, provided that the friction material is always fixed on the steel back and cannot fall off. The bonding strength between the friction material and the steel back alone is not enough, and it cannot cope with the shear force generated during friction under various working conditions. The function of the adhesive is to bond the friction material and the steel back together, improve the bonding strength of the friction material and the steel back, and ensure that the brake pads can work stably.

4 Backplane

Because it is located behind the friction material, the steel plate on the brake pad combined with the friction material is also called the back plate or steel back.

5 muffler

The muffler sheet is also called anti-vibration sheet. Its material is generally made of single-layer or multi-layer thin steel sheets and rubber. Improve braking comfort. What kind of sound-absorbing sheet material is selected needs to be determined according to the formula and the results of the bench, and there is no fixed mode.

6 Accessories

Depending on the model, the steel back also needs to install some functional metal accessories, such as piston jaws, rivet springs, mechanical wear indicators, electronic wear indicators, etc. Some of their functions are to connect the brake pads with the caliper, and some are to remind the owner to replace the brake pads after the brake pads are worn.