Since 2012 the Chinese government issued the ” ‘Twelve five’ national strategic emerging industry development plan “, to December 2016 introduced “‘Thirteen Five’ national strategic emerging industry development plan”, China’s new materials industry achieve great development in recent years. Especially for basalt fiber manufacturing technology which has its own intellectual property rights come from behind, reached the international advanced level.

Basalt fiber is made of silica, alumina, calcium oxide, magnesium oxide, iron oxide and titanium dioxide and other oxides of the basalt stone material, melting in the 1450 ℃ ~ 1500 ℃ high temperature. Through the platinum and rhodium alloy wire drawing low-speed drawn from the continuous fiber. It has wide range of applications. Its performance is similar to common carbon fiber, but its price is only 1/10 of the carbon fiber. There is less waste during production process and less impact on the environment. Also, the product can be discarded directly and depredated in the environment without any harm. The material is a veritable green and environmentally friendly, so the market application space is very broad.

Image: Basalt Fiber

Recently, the mainland’s first basalt fiber and civilian integration forum and project cooperation signing ceremony has been successfully held, marking the new basalt composite materials comes into the market.
The material of our company’s Samuel vertical axis wind turbine blades is basalt fiber special which has high strength, electrical insulation, corrosion resistance, high temperature and other superior features. Compared with the traditional glass fiber, its chemical properties, physical properties, mechanical properties, high temperature stability performance are unparalleled advantages.

Left: Carbon Fiber; Right: Glass Fiber

First, in terms of chemical performance, basalt fiber contains K2O, MgO, TiO2 and other components, which improves the chemical resistance of fiber corrosion and waterproof. Table a is the comparison of chemical stability between basalt fiber and glass fiber. It can be seen from the comparison, in the acid solution (2mol / LHCL) for 3h, the basalt fiber weight loss rate is 2.2%, while the alkali-free glass fiber loss rate is 38.9%, almost 20 times of basalt fiber, which indicating that basalt fiber in the acidic medium has more stable chemical properties. Its acid resistance is much better than glass fiber. After 2 h boiling in alkaline solution (2 mol / L NaOH), the weight loss rate of basalt fiber was 20% lower than that of alkali-free glass fiber, indicating that basalt fiber had better alkali resistance than E-glass fiber (Note: alkali-free glass fiber is the best fiber in the glass fiber capacity). In boiling aqueous solution, the basalt fiber water resistance is also much better than glass fiber, is about 3.5 times compare to the glass fiber. In aqueous solution at room temperature, the basalt fiber has a water absorption (%) of 0.02, while the alkali-free glass is 1.7, and its water resistance is 85 times that of glass fiber.

Table a

Secondly, in the physical performance, basalt is refractory ore, melting temperature is above 1500 ℃, sintering temperature is up to 1060 ℃, the effective use of ordinary basalt fiber temperature range is -260 ~ 700 ℃, special basalt fiber is as high as 982 ℃, indicating that basalt fiber has excellent high temperature and low temperature performance, the use of temperature range is much higher than other types of fiber basalt and the fiber thermal conductivity is lower than other types of fiber. Thus it has excellent insulation performance. Sound absorption coefficient of basalt fiber is greater than glass fiber and other fibers; as a result, it is an ideal sound insulation material. The volume and resistance ratio of basalt fiber is greater than alkali-free glass fiber. It has excellent electrical insulation properties, which is an ideal electrical insulation electronic material.

Table b lists the physical properties of the various fiber materials.

Again, in terms of mechanical properties, basalt fiber has a high tensile strength, see table c. And it is equivalent to alkali-free (E) glass fiber and carbon fiber, and highest in all categories of fiber. The elastic modulus of basalt fiber is 1.5 times that of alkali-free glass fiber, 1.9 times higher than that of high strength S glass fiber, only lower than carbon fiber. From the mechanical properties, basalt fiber is between the carbon fiber and glass fiber, far better than polypropylene and other chemical fiber and wood fiber. Therefore, the basalt fiber is a very ideal composite fiber reinforced.

Table c

Finally, in addition to the above properties, the basalt fiber also has excellent high temperature stability. High temperature stability refers to the heating and other high temperature conditions to maintain its mechanical, physical and chemical properties. Table d lists the comparison of basalt fiber and alkali-free glass fiber under high temperature tensile strength. From the comparison can be seen, the high temperature mechanical properties of basalt fiber is much better than E-glass fiber. The experiment also pointed out that basalt fiber also has excellent high temperature chemical stability. Basalt fiber has lost just part of the strength in 70 ℃ under the action of hot water after 1200h, and in the same condition, alkali-free glass fiber has lost all strength after 200h.

Table d

These advantages of the above characteristics to ensure that the stability and reliability of the wind turbine produced by our company, and also in strong winds, high temperature, coastal and other environments, it can work properly, and regardless of the environment, can guarantee more than 15 years of use life.