What Is Metal Spinning?

Metal fiber refers to a fiber-shaped material with a high metal content and a continuous distribution of metal materials with a lateral dimension in the micron order. Fibers that discontinuously disperse metal fine powder in organic polymers are not classified as metal fibers. ^[1]

Metal fibers are generally up to the micron level. For example, stainless steel fibers generally have a diameter of about 10 m, and the average diameter of fine stainless steel fibers currently on the market is 4 m. Metal fiber has good mechanical properties, not only high breaking strength and tensile specific modulus, but also resistance to bending, good toughness; good electrical conductivity, antistatic, such as tungsten fiber used as the filament of incandescent light bulbs At the same time, it is also an important material for preventing electromagnetic radiation and conduction and electrical signal transmission; it has high temperature resistance; stainless steel fibers, gold fibers, nickel fibers, etc. also have good chemical resistance, and are not easy to oxidize in the air.

Metal fibers have the following characteristics:

(1) The metal fiber can be operated at a temperature of 500 to 590 ° C (930 to 1100 ° C), and may be used in more complex systems in the future.

(2) The metal fiber can withstand high pressure drop, purification ability and stability under high temperature.

(3) The metal fiber has an irregular cross section and a conventional surface area, so that it has a very large specific surface area. ^[2]

Metal fibers can be prepared by drawing, spinning, cutting, grinding, and plating metal sintering.

1) drawing method

Ordinary single wire drawing can obtain extremely fine fibers, and its cross-sectional shape and surface state can reach the best state, with smooth surface and accurate size. However, the production efficiency is low and the cost of the mold is high, so the price is very expensive. By adopting the cluster drawing method, tens or even hundreds of wires are simultaneously drawn on a mold to greatly improve production efficiency and reduce costs. The cluster drawing is to pull the raw metal wire in a sheath (such as a copper sheath) and repeat it several times. The annealing process is added in the middle to cut into segments after reaching a certain diameter, and then they are combined together. Pull until the required fiber diameter is obtained. The coating material can be dissolved with an acid (such as nitric acid) to obtain the desired metal fibers.

2) spinning method

The spinning method can directly produce metal fibers from liquid metal, and the cost is low, but special equipment is required. For example, after the metal is melted, the molten liquid is caused to flow out from the small hole at the bottom of the container by mechanical force or gas pressure, and solidified in an appropriate atmosphere. Immediately after the molten metal flows out of the fine L, the bonding force between the metal fiber grains is very short, and it has "hot brittleness", so the small force can cut the metal fiber into short fibers. Therefore, short metal fibers with uniform length can be obtained by adding the falling metal fibers with a certain shear force.

(1) Used as a wire for power transmission and electric signal transmission in smart clothing.

(2) For antistatic materials in general functional clothing, if metal short fiber blends are used, the weight blending ratio is less than 10%; if metal fiber filaments are used, the weight blending ratio is less than 2.5%. Eliminate all kinds of friction, induction and other static electricity. This is very suitable for the safe operation of electrical appliances in the transportation of flammable and explosive materials such as oil, gas fields and flammable and explosive products, and transportation of flammable and explosive materials such as petroleum and hot air.

(3) The metal fiber can be embedded in the fabric to achieve a good electromagnetic wave shielding effect. It has a wide range of applications in military, aviation, communications, and classified shielding environments.

(4) Filters for chemical agents, processing materials, waste water and wastewater filtration, high-temperature dust filters, and materials that require high strength, wear resistance, and conductive transport belts.

(5) Reinforcement materials in metal composite materials, such as explosion-proof tires, connecting rods of automobile engines, etc.

(6) Other special materials, such as making conductive paper, filament of incandescent light bulb, etc. ^[1]