2. Accurate material measurement system. Homogeneous material mixing system 4. Good material atomization system. Convenient material cleaning system 1.2.5 polyurea adopts two-liquid spray polyurethane polyurea elastomer composition produced by Dow company. The reaction speed of this composition is extremely fast, and it can be cured within 20 seconds, and the walking strength can be reached within 10 minute. 1.2.6 polyurea anticorrosive coating is formed by mixing and reacting polyisocyanate, amino-terminated polyether and amine chain extender in special spraying equipment under high pressure and rapid impact. Different from the two-component reaction of polyurethane, it takes amino-terminated polyether and amine chain extender as active hydrogen components (B
Component), so the reaction activity with polyisocyanate (component A) is extremely high. Even below 0℃, the reaction can be completed instantly without adding any catalyst, which overcomes the influence of environment, temperature and humidity, and eliminates the defects such as bubbles, pinholes and weakened adhesion. 1.2.7 The material conveying system of spraying construction H 15 is equipped with two 2: 1 pneumatic feed pumps, which can stably feed the main engine with appropriate pressure. They are respectively planted in 200-liter vats of material A and material R, which are connected by threads and reliably sealed by sealing rings. The feed pump can also be used for small packaging barrels. Material A is very sensitive to moisture, which will form crystals and pollute proportional pumps, filters, hoses and spray guns. H35 can be equipped with an air dryer, and the air pipe is connected to the vat to supply dry air with pressure (dew point -45℃). Nitrogen is most suitable for use in high humidity conditions. The gas in the two barrels is connected, so the two barrels have the same initial pressure. Note that the initial pressure should be less than the safe pressure of the barrel (usually not more than 0.4 bar). R material can be evenly mixed with pigment, filler and polyether by pneumatic or electric stirrer. The rotation speed of the agitator should not be too high to avoid moisture mixing into the material. In order to prevent the excessive viscosity of raw materials from affecting the feeding in cold winter, a drum heater can be installed on the charging barrel, and a preheating rod can be installed between the feeding pump and the main engine to heat the raw materials. The minimum feeding temperature is 20℃. If the temperature is too low, the load of the feed pump and the proportional pump will increase, and a cavity will be formed in the pump. It is best to have 2X330 storage tanks with circulating heating. The raw materials of the equipment can also be loaded on the insulated car. Material metering system (host): The host is used for accurate metering and temperature control of materials, and provides stable high-pressure logistics for the mixing system. The main engine is driven by hydraulic pressure and adopts advanced Rexroth hydraulic pump. The metering pump is a piston pump arranged in a straight line (as shown in Figure 4), so that the two proportional pumps A and R generate the same high pressure, which balances the pressure on both sides of the hydraulic cylinder and eliminates the asymmetric load. The maximum working pressure of H35 is 3500psi(24. 1Mpa). With the increase of working pressure in the spraying process, the physical properties of the coating are also improved, and the atomization effect is better and the surface quality is higher. The dynamic pressure when spraying polyurea elastomer is generally between 2000 psi (14 MPa) and 2800 psi (19.5 MPa). The working static pressure is between 2500 and 3000 psi. There is a ball valve sealing device (pump seat) between the feeding pump and the proportional pump to ensure that the piston of the proportional pump has the same amount of material output when it moves left and right. There is no one-way valve in the proportional pump, so the pressure fluctuation caused by the opening and stopping of the one-way valve is small, and the one-way valve can be maintained without disassembling the proportional pump. The inner wall of the hydraulic cylinder and the piston rod are plated with hard chromium to prolong the service life. Material A is very sensitive to moisture, so Gusmer took two measures to protect the seal of material A.. Right side of material proportional pump
There is a circulating oil seal system, so that the pump shaft seal is immersed in the washing of lubricant to prevent isocyanate from consolidating on the pump shaft, which greatly prolongs the sealing life. With telescopic structure, the shaft of material A pump is completely retracted into the cylinder every time it stops, so as to avoid contact with moisture. Apply elastomer within 12-48 hours after applying sealing primer. If the interval is more than 48 hours, re-apply a sealing primer one day before spraying the elastic layer, and then apply the elastic layer. Polyurea elastomer spraying construction is not affected by temperature and humidity, and the thickness of one construction is several millimeters or even centimeters. 1.2.8 The polyurea spray coating shall be thick enough and uniform, and the coating shall be firm without foaming, cracking and shedding. 1.2.9 the quality inspection shall be carried out during the anti-corrosion work. The bidder shall determine the inspection points and to-be-inspected points in the construction organization design according to the process requirements, and can enter the next working procedure only after passing the inspection. The inspection method includes dry layer thickness inspection and appearance inspection of the whole anticorrosion surface, and the following situations are not allowed:-extremely uneven anticorrosion-foaming, bubbles, cracks and particle burial, and the performance characteristics of peeling 1.3 polyurea elastomer: 1.3. 1 contains no catalyst, and can be sprayed on any curved surface, inclined surface or slope. It takes 5 seconds for gel to reach the walking strength 1 min. 1.3.2 is insensitive to moisture and temperature, and is not affected by ambient temperature and humidity during construction. (Can be built on ice; -28℃ construction; It can be cured in the freezer. 1.3.3 two-component, 100% solid content, no volatile organic compounds (VOC), environmental protection. 1.3.4 can be sprayed or poured according to the volume ratio of 1: 1, and the thickness of one construction can vary from several hundred microns to several centimeters, which overcomes the shortcomings of previous construction. 1.3.5 Excellent physical and chemical properties, such as tensile strength, elongation, flexibility, wear resistance, aging resistance and corrosion resistance. 1.3.6 has good thermal stability and can be used for a long time at 120℃. The heat-resistant type can be used for a long time at 180℃ and can withstand short-term thermal shock at 350℃. 1.3.7 You can add various pigments and dyes to make products with different colors like ordinary paints.