NFJ Foamy Fiber (Porous Strengthening Material)

In the last several years, the NFJ Foamy Fiber (porous strengthening material) has been a novel material used in the polymer based-friction materials. With the development of high speed and heavy railway vehicles, and the requirement of environment protection, it is demanded that the friction materials should provide some new properties. It is widely recognized that the next generation friction materials should be light-weight, porous, elastic, low density, have rough surface, decrease the dosage of polymers, including rubber and resin used as binders in the friction materials. This will reinforce the mechanical and friction properties of the braking components, reduce the noise and increase the vehicle comfort. The enhanced binding strength of inorganic materials can reduce the addition of nonferrous metals, which will prevent their harm to the human beings.

In recent years, the developed countries have set up the policy that the nonferrous metals are forbidden to be used in friction materials due to the fact that the dust induced during the wear of friction materials can do harm to human beings, and contaminate water once it enters into the earth.

Our company has developed foamy fiber, which is a porous strengthening material. It is mainly made of iron together with carbon less than 0.02 wt.%. Fe is an element beneficial to the human beings. The NFJ foamy fiber，which is produced through special technique, is loose, porous, plastic, low density and with rough surface and resistant to rust. It has been widely used in the friction materials for railway and automobiles.

1. Principles

The NFJ foamy fiber, which is mainly made of iron, is crashed, sieved and changed to porous powders by adding the blister at high temperature. The product is loose, porous, plastic, low density and with rough surface and resistant to rust. We can provide different size of powders according to the customers’ requirement.

2. The features of NFJ foamy fiber

(1) It reinforces the friction materials.

Since the NFJ foamy fiber is a kind of low carbon material with rough and porous surface, during the mixing the fine fibers can enter into the pores of the NFJ foamy fiber. Moreover, during the compressing process, these fibers can deform into wider, thinner and longer fibers, and have a good binding effect with other ingredients, and increase the impact resistance by acting as a binding component.

(2) It greatly decreases the dosage of organic binder.

The NFJ foamy fiber can deform into wider, thinner and longer fibers, and have a good binding effect with other ingredients, therefore the dosage of the organic binder can be decreased greatly. Additionally, since the NFJ foamy fiber contains low carbon, the addition of these fibers can decrease the dosage of organic binder and the side effect of carbonization and decomposition of these polymer binders.

(3) It can improve the friction properties.

Since the NFJ foamy fiber is loose, porous and elastic, it can improve the friction properties of the friction materials.

(4) It can improve the vehicle comfort

Since the NFJ foamy fiber is not rigid during braking, it offers excellent damping and elastic adjusting properties, and improves the vehicle comfort.

(5) It decreases the noise

Since the NFJ foamy fiber is porous and low density, it can absorb a large amount of noises.

(6) It decreases the temperature of the friction materials

Since the NFJ foamy fiber is a metallic and porous material, it is easy to release the heat induced from braking through these metallic network with large surface areas and excellent thermal conductivity. Thus, the surface temperature of the friction material is greatly decreased.

(7) It facilitates the evenly mixing of ingredients

Since the NFJ foamy fiber is loose, porous and with rough surface, its density is very similar with those inorganic ingredients, which facilitate the homogeneous mixing of each ingredient.

(8) It can prevent the sparkle and metal tessera。

The microstructure of NFJ foamy fiber had been modified during production, so it will not result in the braking sparkle and metal tessera during the braking.

3. Technique index

(1) chemical properties

（2）Physical properties

Color: black or gray

Shape: loose and porous particles

Water content: ≤0.8%

Particle size: －20M～＋200 mesh, according to the order of customers

Density:

4. Notices

（1）Suitably increase the compression force

The NFJ foamy fiber with rough surface is loose, porous and plastic, and it deforms into wider, thinner and longer fibers during the compressing process. The larger the compression force, the bigger the deformation, the higher the reinforcing effect, and the better binding strength with other ingredients.

 (2) Suitable dosage:

Once the NFJ foamy fiber is used in the friction materials, the dosage should be enough so that it can form a metallic network for heat emission. It is suggested that the dosage of the NFJ foamy fiber should be adjusted between 20%—40% in the friction materials.

（3）Suitable particle size distribution

We can provide different sizes of the NFJ foamy fibers, such as -20 to +40 mesh, -40 to +120 mesh and -80 to +200 meshes. Once the NFJ foamy fiber is used in the friction materials, we suggest using several kinds of NFJ foamy fibers with different particle sizes. The large particles provide less density and good plastic deformation, and the fine particles offer the homogeneous distribution of particles.

(4) It is noted that the organic materials start to carbonize and decompose, and the binding strength is decreased at high temperature. Thus, we should decrease the dosage of organic materials and prevent and severe wear of the friction materials at high temperature.

(5) Package and storage:

Double-layer packing (inner plastic bag and composite paper bag outside), 25 kg per bag, damp-proof packing. The validity is six months.

Main Functions:

1、Enhances the friction material.

2、Substantially reduces the usage of binders.

2、Improves friction performance.

3、Enhances vehicle comfort.

4、Reduces noise.

5、Lowers friction temperature.

6、Facilitates uniform mixing during blending.

7、Prevents metal sparks and metal embedding.