Application of polyurethane pultrusion in the field of composite materials

01 Application in the field of power engineering

With the rapid development of China's economy and power grid, the application trend of new composite materials is highlighted year by year. Traditional poles are vulnerable to severe damage in harsh climates, which can devastate the power grid.

Continuous fiber reinforced polyurethane composite pole light, high strength, good electrical insulation performance, can replace the traditional pole in the coastal, mountainous, high pollution and other special areas of use. Therefore, the China Electric Union standard "distribution network composite pole" stipulates that polyurethane resin must be used, and the pole should be formed by pultrusion process.

Polyurethane resin insulated power tower, its quality is only 1/10 of the concrete pole, and can be directly formed into the support, saving transportation, installation and labor costs. Due to the excellent characteristics of polyurethane itself, there is no need to add curing agent and anti-aging agent in the molding, which reduces the production cost of power tower.

02 Application in building doors and Windows

The application of continuous fiber reinforced polyurethane pultrusion materials in construction is mainly for door and window profiles. Although aluminum alloy Windows, PVC plastic steel Windows, aluminum clad wood Windows and other doors and Windows have good thermal insulation performance and are widely popular in the market, such materials will cause a lot of energy loss in the production process, easy to produce solid waste and harmful volatiles, and poor fire resistance.

Polyurethane pultrusion door and window profile molding, no styrene volatilization, avoid environmental pollution, in line with the "green environmental protection" concept. Because glass fiber has good flame retardancy and heat resistance, polyurethane pultrusion material itself has fire resistance. Moreover, the heat transfer coefficient of polyurethane pultruded door and window profiles is only 0.22W/(m2·K), the thermal resistance is 9.96mK/W, and the thermal insulation performance is better. The heat transfer coefficient and air tightness of several energy-saving Windows are shown in the following table.

Compared with other material doors and Windows, polyurethane pultrusion doors and Windows profiles have stable dimensions, good air tightness and sound insulation. According to the national standard "Building doors and Windows airtight, watertight, wind pressure resistance performance classification and testing methods" test, polyurethane composite doors and Windows can reach 8 levels of air tightness, 6 levels of water tightness, and 5 levels of sound insulation performance, which has been widely used.

03 Application in the field of railway ties

Wood sleeper and reinforced concrete sleeper are the two main sleeper materials at present, the former is not corrosion resistant, short service life, and against environmental protection; The latter raw materials are cheap and easy to obtain, stable performance, long service life, but its elasticity is poor and hardness is high, easy to break. In contrast, fiber reinforced polyurethane synthetic sleepers, regardless of the properties of the raw materials themselves or the characteristics of the pultrude process, have brought great advantages to the construction and application of sleepers.

A new kind of synthetic sleeper prepared by pultrusion molding process. The performance test results show that the bending load resistance of the new polyurethane composite sleeper can reach 181kN, and the pulling strength of the screw can reach 76kN. This kind of sleeper not only has excellent performance in shear strength, impact strength and other mechanical properties, but also has excellent performance in corrosion resistance and aging resistance.

04 Applications in other fields

Automobile floor: This automobile floor strength is high, light weight, improve fuel economy; There will be no small molecule volatilization during use, moisture resistance and corrosion resistance, and has a certain flame retardant, safe and reliable; The thermal expansion coefficient of fiber reinforced polyurethane is small, there is no thermal deformation problem, and it has a long service life.

Body: Due to the high fiber volume fraction, the composite has excellent mechanical properties and lower mass, reducing fuel consumption and environmental damage.

Photovoltaic frame and bracket: Continuous glass fiber reinforced polyurethane pultrusion composite material can be used to make photovoltaic module frame and bracket, which is a rapid development of new market, with composite materials instead of aluminum alloy frame, can play a cost reduction, lightweight and other roles, and composite material good insulation, chemical resistance and other properties make it more performance advantages in the sea, saline-alkali land and other fields.

At present, a number of component companies have completed the certification of related products, in part of the mass production stage, and the composite border has even become a special selling point of photovoltaic modules.