perforated metal sheet sizes

Application: Mainly used in communication devices, medical equipment and braided mesh, brush, steel cable, filter screen, high pressure pipe, construction, technical products and other professional electric galvanized wire: is a low carbon steel as core wire, metal composite materials processed by wire drawing, electric galvanized technology.

1. Principle. Because zinc does not change easily in dry air, and in humid air, the surface can form a very dense film of zinc carbonate, which can effectively protect the interior from corrosion. And when the coating is damaged for some reason and the matrix is not too large, the zinc and steel matrix form a micro cell, so that the fastener matrix becomes the cathode and is protected. It is widely used in automobile transportation and other industries, but what is needed is the trivalent chromium passivation layer, zinc nickel alloy plating closed coating, reduce the harmful and toxic layer of hexavalent chromium passivation.

The use of galvanized anticorrosion treatment is better, the metallurgical connection between galvanized layer and steel, combined with the appearance of steel as a whole, making the coating more durable, more reliable. In the suburbs, the galvanized thickness of hot dip galvanized can adhere to more than 50 years without repair, in the suburbs or near the seaside, galvanized layer can adhere to more than 20 years without repair, is the choice of anti-rust and anti-corrosion. Coating has strong toughness, in the process of transportation or use, can resist extrusion, withstand some damage, hot dip galvanized anticorrosion treatment both save time and effort, and faster than other processing, than dipping, spraying to save much time and effort.

Although galvanized hook mesh is outstanding because of its surface, this does not mean that this hook mesh product is not useful. From the point of view of people’s use of it, this hook mesh products through a surface of galvanized treatment, whether it is wind and sun, or man-made inadvertent damage, will not bring a little harm to it, so the more comprehensive use of galvanized hook mesh products will then be widely used in several fields.

2: Clarification mechanism of coagulant

Chemical coagulation is a process in which chemical agents (coagulants) are added to water treatment to make colloidal dispersion system destabilize and agglomerate. In the coagulation process, small suspended particles and colloidal impurities are aggregated into larger solid particles to separate particulate impurities from water, which is called coagulation clarification.

After adding coagulant into water, colloidal particles and other small particles can be polymerized into larger flocs through the comprehensive action of mixing, coagulation and flocculation. The whole process of coagulation and flocculation is called coagulation.

(1) Destabilization and condensation of colloids

Adding electrolyte to water can compress the electric double layer and destabilize the colloid. The main mechanism is that the electric double layer of colloidal particles in water is compressed or neutralized by adding aluminum salt or iron salt coagulant. The coagulant and raw water are mixed rapidly and evenly, and a series of chemical reactions are produced to destabilize. This process takes a short time, generally about 1 min. Some cationic polymers can also play a role in the destabilization and condensation of colloids in water. These polymers have a long chain structure and positive charge in water. Their destabilization and condensation of colloids in water is due to the interaction of van der Waals force adsorption and electrostatic attraction.

(2) Flocculation and formation of floc (alum)

The particle size of the initial flocculate formed by colloid destabilization and coagulation in water is generally more than 1 m. at this time, Brownian motion can no longer push them to collide and form larger particles. In order to make the initial flocs collide with each other to form large flocs, it is necessary to input additional energy into the water to produce a velocity gradient. Sometimes it is necessary to add organic polymer flocculant into water, and the adsorption bridging effect of long chain molecules of flocculant is used to improve the probability of collision and adhesion. Flocculation efficiency usually increases with the increase of flocculate concentration and flocculation time.

Compared with polyaluminum chloride, polyaluminum chloride has the advantages of high density, fast settling speed and wide pH adaptability; the coagulation effect is less affected by temperature than that of polyaluminum sulfate; however, when adding ferric salt, it should be noted that when the equipment is not in normal operation, the iron ions will make the effluent color, and may pollute the subsequent desalination equipment.

Among the raw materials for coating production, titanium dioxide is more ideal, followed by lithopone. The covering power of lithopone is only that of titanium dioxide, and the price of lithopone is much lower than that of titanium dioxide, so lithopone still occupies a large market share.

Lithopone Market Outlook - 2020–2027

Avoiding exposure

Lithopone 30% CAS No. 1345-05-7 / Production Method

Resumen–En este artículo se discute el descubrimiento del litopón fosforescente en dibujos a la acuarela por el artista americano John La Farge, fechados de 1890 a 1905, y la historia del litopón en la industria de los pigmentos a finales del Siglo XIX y principios del Siglo XX. A pesar de tener muchas cualidades deseables para su uso en pintura para acuarela o pinturas al óleo blancas, el desarrollo del litopón como pigmento para artistas fue obstaculizado por su tendencia a oscurecerse con la luz solar. Su disponibilidad para los artistas y su adopción por ellos sigue siendo poco clara, ya que por lo general los catálogos comerciales de los coloristas no eran explícitos al describir si los pigmentos blancos contenían litopón. Además, el litopón se puede confundir con blanco de plomo durante el examen visual, y su fosforescencia de corta duración puede ser fácilmente pasada por alto por el observador desinformado. A la fecha, el litopón fosforescente ha sido documentado solamente en otra obra mas: una acuarela por Van Gogh. Además de la historia de la fabricación del litopón, el artículo detalla el mecanismo para su fosforescencia, y su identificación con la ayuda de espectroscopía de Raman, y de espectrofluorimetría.