As we all know, even matching with the standard Inlet and exhaust silencers, the noise of Roots blower is always a problem;
What is known is that the main structure of acoustic enclosure is its enclosure plates. When the enclosure plates have enough sound insulation, which can block the noise of the sound source machine and equipment, so that the noise can be reduced below the specified allowable sound level.
According to the law of quality, the structure of the enclosure plate should be heavy, such as brick, stone, concrete or thick steel plate. However, in most cases, due to the space conditions of the site, the maintenance of the machine and the disassembly and transportation of the acoustic enclosure, the structure of the enclosure plate is required to be light and convenient, so that the enclosure plates of this kind of sound insulation is generally made of thin metal plate with a certain thickness The sound-absorbing material of the material. To determine the structure of acoustic enclosure, the sound insulation capacity of the enclosure can be determined according to the requirements of insertion loss, and then the specific structure can be selected according to the sound insulation capacity of relevant structures and the actual situation.
EVP VACUUM introduced 80 mm thick galvanized sheet acoustic enclosure plates 20 years ago. The surface of the product is sprayed with plastic treatment process, which has many advantages compared with the traditional spray painting process. Here is a brief introduction of the spray molding process:
The main component of sprayed plastics is spray powder. It usually uses organic polymer, such as styrene acrylic emulsion, pure acrylic emulsion, epoxy acrylic emulsion, vinyl acetate ethylene copolymer emulsion, water emulsion epoxy resin and so on. Rutile titanium dioxide, lithopone, zinc oxide, talc, mica, quartz and fibrous materials such as asbestos are commonly used in the mixed fillers.
Plastic spraying is a kind of surface treatment method of spraying plastic powder on parts. Its treatment process is a kind of metal surface treatment technology which has been widely used in the world since 1980s. Compared with the common spray painting surface treatment, this technology has excellent coating appearance quality, more dense coating, strong adhesion and mechanical strength, and high corrosion resistance and wear resistance. Therefore, it is often used in box, cabinet and other products. Its working principle is that the plastic powder is not charged by high-voltage electrostatic equipment. Under the action of electric field, the coating is sprayed on the surface of the workpiece, and the powder will be evenly distributed Evenly adsorbed on the surface of the workpiece to form a powdery coating. After the powdery coating is baked at high temperature and then leveled and solidified, the plastic particles will melt into a dense final protective coating with different effects and firmly adhere to the surface of the workpiece.
The spray molding process of EVP VACUUM acoustic enclosure plates is as follows:
Objective: to remove the oil, dust and rust on the surface of the workpiece, and form a “phosphating layer” on the surface of the workpiece, which is anti-corrosion and can increase the adhesion of the spray coating.
Main process steps: degreasing, derusting, phosphating and passivation. After pretreatment, there is not only no oil, rust and dust on the surface of the workpiece, but also a uniform and rough gray phosphating film which is not easy to rust on the original silver white glossy surface, which can not only prevent rust, but also increase the adhesion of the spray layer.
2. Electrostatic spraying
Objective: to evenly spray the powder coating on the surface of the workpiece.
Process steps: using the principle of electrostatic adsorption, evenly spray a layer of powder coating on the surface of the workpiece
3. High temperature curing
Objective: to heat the powder coating on the surface of the workpiece to the specified temperature and keep it warm for the corresponding time to make it melt, level and solidify, so as to obtain the desired surface effect of the workpiece
Process steps: pushing the sprayed workpiece into the curing furnace, heating it to the predetermined temperature (generally 185 degrees), and keep it for the corresponding time (15 minutes); open the furnace and take it out for cooling to get the finished product.
EVP Vacuum roots blowers adopts the standard spraying thickness to avoid the phenomenon of too high thickness and sagging, resulting in extremely uneven plastic film thickness and affecting the effect of spraying; EVP has adopted the spraying treatment process for the acoustic enclosure since 2009, replacing the original spraying process. Our SSR series, ZW series and ZG series roots blower with spraying acoustic enclosure products have been widely used in petroleum, chemical, cement and other occasions, the noise level can be reduced to 75dB~80dB;
Company: Shanghai EVP Vacuum Technology Co.,Ltd
Key words: roots blower; three lobes roots blower; acoustic enclosureWhy Plastic powder spray on Acoustic Enclosure of EVP Roots Blower?