Large diameter spiral pipe corrosion refers to the use and transportation of large diameter spiral pipe in the use of the environment and the transmission medium of the lead to the chemical or electrochemical reaction to attack corrosion. In order to avoid or manipulate large-diameter spiral tube corrosion, scientists are looking for a new, higher and more useful approach.
      The new large-diameter spiral pipe anti-corrosion technology has emerged, spiral pipe equipment manufacturers to inform you in general can be divided into the following types:
The main type of large diameter spiral pipe anticorrosive coating
1, grease coating - for corrosion resistance is not demanding in the atmosphere.
Grease coating is based on dry oil as the primary film of a class of paint. Its characteristics are easy to produce, brushing good, good moisture on the surface, cheap, flexible paint; but the film dry slow, soft film, mechanical function is poor, acid and alkali resistance, water resistance and organic Poor solvent. Dry oil and anti-rust paint often cooperate with the composition of anti-rust paint, corrosion resistance is not demanding for the atmosphere.
2, the country paint
Paint, also known as raw lacquer, large paint, is one of our specialty. Raw lacquer is a kind of milky white viscous liquid flowing from the growing lacquer tree to cut out the bark, and the filter is removed by fine cloth. It is painted on the appearance of the object, the color quickly from white to red, from red to purple, longer time can become a solid bright black paint film.
Urushiol is the primary ingredient of raw lacquer, content of 30% to 70%. Generally speaking, the higher the content of laccatin, the better the quality of lacquer.
Strong adhesion of the paint, film tough, shiny, it is resistant to soil corrosion, more water, oil. Defects are toxic and easy to make skin allergies. In addition it is not resistant to strong oxidants, poor alkali resistance. Now there are many modified lacquer coating, to varying degrees, to overcome the above shortcomings.
3, phenolic resin coating
Mainly alcohol-soluble phenolic resin, modified phenolic resin, pure phenolic resin. Alcohol-soluble phenolic resin coating corrosion resistance is better, but the construction is not convenient, flexibility, adhesion is not very good, the use of certain restrictions. So often need to modify the phenolic resin. Such as rosin modified phenolic resin and tung oil refining, to participate in various pigments, grinding can be made of various enamel, the film tough, low prices, widely used in furniture, doors and windows of the painting. Pure phenolic resin coating strong adhesion, water resistance heat, corrosion resistance, good weather resistance.
4, epoxy resin coating
Epoxy coating adhesion is good, the metal, concrete, wood, glass, etc. have excellent adhesion; alkali, oil and water, excellent electrical insulation. But poor anti-aging. Epoxy anticorrosive coatings are typically composed of epoxy and curing agents. The properties of the curing agent also affect the function of the paint film. Commonly used curing agents are: ① fatty amine and its modified objects. Features can be cured at room temperature, unmodified fatty amine toxicity. ② aromatic amines and modified substances. Features are slow response, often heat curing, toxicity is weak. ③ polyamide resin. Features are better weather resistance, less toxic, good elasticity, corrosion resistance slightly worse. ④ phenolic resin, urea-formaldehyde resin and other synthetic resin. These resins and epoxy resins are cross-linked with high temperature baking, and the film has excellent corrosion resistance and excellent mechanical and decorative properties.
Epoxy ester resin coating is a one-component coating system with epoxy ester resin as film-forming material. The epoxy ester resin is composed of epoxy resin and vegetable oil fatty acid ester. The coating compared with the general cost of epoxy paint is relatively low, poor alkali resistance. Commonly used for a variety of metal primer and chemical plant outdoor equipment anti-corrosion paint.
5, polyurethane coating
Polyurethane resins for use in anticorrosive coatings often contain two components: isocyanate groups -NCO and hydroxyl groups. When used, the two-component mixture is reacted and solidified to form a polyurethane (polyurethane).
Polyurethane coating features: ① physical mechanical function is good. The film is strong, flexible, bright, full, wearable, strong adhesion. ② excellent corrosion resistance. Oil, acid, chemicals and industrial waste gas. Alkali resistance slightly lower than epoxy coatings. ③ anti-aging is better than epoxy paint. Commonly used as a finish, can also be used as a primer. ④ polyurethane resin and a variety of resin miscible, can be adjusted within a wide range of formulations to meet the various requirements. ⑤ can be cured at room temperature or heat curing, the temperature is low (0 ℃) can also be cured. ⑥ polyisocyanate components of the storage stability is poor, it is necessary to block moisture, to avoid jelly. Polyurethane paint prices are high, but the use of long life.
6, polyethylene, polypropylene resin coating
Polyethylene resin anti-corrosion coating is made of monomer resin for the film coating material. During which the polyethylene coating has been a lot of production and use.
Polyethylene pipe corrosion resistance, high mechanical strength, water resistance, quality and stability, construction convenience, applicability is good, do not pollute the environment. PE water absorption is low (less than 0.01%), together with high epoxy strength, PE water absorption and hot melt adhesive soft and so good, have a high anti-corrosion reliability, the defect is: compared with other input data costs, costly. The source of raw materials for the coating, in the corrosion has been a lot of use.
7, furan resin coating
Furan resin coating resistant to a variety of non-oxidizing inorganic acid, electrolyte solution, a variety of organic solvents, alkali resistance is also very outstanding, but the antioxidant is not good.
Furan resin series of anti-corrosion coatings, including furfuryl alcohol resin coating, furfural acetone formaldehyde resin coating and modified furan resin coating.
8, rubber coatings
Rubber anti-corrosion coating to chemical treatment or mechanical processing of natural rubber or synthetic rubber for the film-forming material, with solvents, fillers, pigments, catalysts and other processing.
⑴ chlorinated rubber coating. The coating has good water resistance, salt water and salt spray; there must be acid and alkali corrosion, 50 ℃ below the ability of 10% HCl, H2SO4, HNO3, different concentrations of NaOH and wet Cl2. But not solvent, aging resistance and poor heat resistance. The coating is widely used in ships, harbors, chemical and other occasions.
⑵ neoprene coating. The paint resistance to ozone, chemicals, alkali resistance outstanding, good weather resistance; oil and heat, can be made strippable coating. Defects are poor storage stability; coating easy to change color, difficult to make white or light paint.
⑶ chlorosulfonated polyethylene rubber coating. By the polyethylene resin and chlorine and sulfur dioxide (or chlorosulfonic acid) reaction in the system. Coating anti-ozone function is excellent, weatherability obvious, low water absorption, oil resistance, temperature, can be used at 120 ℃ above, -50 ℃ is not brittle.
9, asphalt coating
Asphalt is one of the important anti-corrosion coatings. Especially coal tar pitch as the best, coal tar pitch paint low price, has the following advantages: ① water, immersed in water for 10 years its water absorption rate of only 0.1% to 0.2%; ② resistance to some chemical media corrosion; On the surface is not full of rusty steel still have excellent moisture; ④ high solid content, can be thick film; ⑤ low prices. Its shortcomings are crisp winter, summer heat, after exposure to some ingredients evaporate and escape will make the film crack. These defects can be improved by participating in some other resins. For example, to participate in chlorinated rubber can improve the dryness of asphalt coating, to improve the winter crisp soft summer defects; to participate in epoxy resin prepared epoxy asphalt coating, both asphalt coating and epoxy paint strengths, in the anti-corrosion Very satisfying role. Asphalt coating has been in the container bottom, bottom, dock gate, cofferdam and other occasions, anti-corrosion effect is very good.
10, heavy anti-corrosion coating
Heavy-duty corrosion coatings are relatively resistant to corrosion-resistant coatings. It refers to the harsh corrosion conditions, anti-corrosion effect than the average corrosion coating several times more than anti-corrosion coating. Its characteristics are excellent resistance to strong corrosive media, excellent durability, the use of life for more than a few years. Mainly for marine structures and chemical equipment, tanks and pipelines.