Glass Fiber for Automotive Brake Pads: Anti-Crack, Wear-Resistant, Well-Dispersed Friction Material Reinforced Chopped Fiber

Glass fiber is a high-performance inorganic non-metallic material with a wide variety of types. Its advantages include excellent insulation, strong heat resistance, good corrosion resistance, and high mechanical strength, but it is brittle and has poor wear resistance. It is manufactured from six types of ore—pyrophyllite, quartz sand, limestone, dolomite, boron-calcium ore, and boron-magnesium ore—through processes such as high-temperature melting, wire drawing, spooling, and weaving. The diameter of a single filament ranges from several micrometers to over twenty micrometers, equivalent to 1/20 to 1/5 of a human hair. Each bundle of fiber precursor consists of hundreds or even thousands of single filaments. Glass fiber is commonly used as a reinforcing material in composites, electrical insulation materials, thermal insulation materials, circuit substrates, and other applications across various sectors of the national economy.

Properties of Glass Fiber Material

Melting Point: Glass is an amorphous material with no fixed melting point. Its softening point is generally considered to be between 500°C and 750°C.

Boiling Point: Approximately 1000°C

Density: 2.4~2.76 g/cm3

When used as a reinforcing material in reinforced plastics, glass fiber is characterized by high tensile strength. The tensile strength under standard conditions is 6.3–6.9 g/d, and 5.4–5.8 g/d in a moist state. It has good heat resistance, with no effect on strength at temperatures up to 300°C. It also possesses excellent electrical insulation properties, making it an outstanding electrical insulation material, as well as being used in thermal insulation and fireproof materials.

Main Characteristics of Glass Fiber

Raw Materials and Applications: Glass fiber has higher temperature resistance than organic fibers, is non-combustible, corrosion-resistant, offers good thermal and acoustic insulation, high tensile strength, and excellent electrical insulation. It is used to manufacture reinforced plastics or reinforced rubber. As a reinforcing material, glass fiber has the following characteristics:

(1) High tensile strength, low elongation (3%).

(2) High modulus of elasticity, excellent rigidity.

(3) Large elongation within the elastic limit and high tensile strength, resulting in high impact energy absorption.

(4) As an inorganic fiber, it is non-combustible and has good chemical resistance.

(5) Low water absorption.

(6) Good heat resistance.

(7) Excellent processability; can be made into various forms such as strands, bundles, mats, and fabrics.

(8) Transparent, allowing light transmission.

(9) Good adhesion with resins.

(10) Low cost.

(11) Difficult to burn; can melt into small glass beads at high temperatures.

Functions of Glass Fiber:

1. Enhance rigidity and hardness: The addition of glass fiber can improve the strength and rigidity of plastics, but it also reduces toughness. Example: flexural modulus.

2. Improve heat resistance and heat deflection temperature: For example, in nylon, the addition of glass fiber increases the heat deflection temperature by at least two times. Generally, glass fiber-reinforced nylon can withstand temperatures above 220°C.

3. Improve dimensional stability and reduce shrinkage.

4. Reduce warping deformation.

5. Reduce creep.

6. For flame retardancy: Due to the wick effect, it may interfere with flame retardant systems and affect flame retardancy.

7. Reduce surface gloss.

8. Increase moisture absorption.

9. Glass fiber treatment: The length of the glass fiber directly affects the brittleness of the material. Improperly treated short fibers may reduce impact strength, while well-treated long fibers can improve impact strength.