Ultrasonic Coatings

Ultrasonic Coatings Ultrasonic coating technique began to be applied with the use of ultrasonic spray nozzles, first introduced to the market in the 1970s, and has become widely used in many sectors such as textiles, nanomaterial production, touchscreen and glass coating, particularly in recent years. Ultrasonic technology, based on converting high-frequency sound waves into mechanical energy, is increasingly being adopted by manufacturers operating in the coating field.

What is Ultrasonic Sound Wave?

The term ultrasonic, formed by combining the Latin word "ultra" meaning beyond and "sonic" meaning sound, is used to describe sound waves above 20 kilohertz that exceed the hearing capacity of the human ear. Many living organisms such as dogs, frogs, dolphins, camels and bats use ultrasonic sound waves to carry out their vital functions. For example, more than 1,100 bat species utilize ultrasonic frequencies through echolocation to obtain food in the dark and use insects they locate using this method during flight as food.

Applications of Ultrasonic Sound Waves

The branch of science studying ultrasonic sound waves is called ultrasonics and forms part of sound studies in physics based on wave motion. The history of ultrasonic applications dates back to the 1880s. Primarily medicine, but also many sectors such as communications, food and textiles have achieved significant gains with the help of ultrasonic science. Ultrasonic technology not only enables the detection of fetus size, position and possible diseases the child may have in the womb, but also makes it possible to precisely measure the depth of wounds in the human body. One of the most important advantages offered by ultrasonic applications at this point is the elimination of potential risks created by procedures such as x-ray or incision (surgical cutting). Additionally, strong shock waves created by microscopic droplets generated through ultrasonic waves are used in detecting and eliminating cancer cells and in the treatment of kidney and gallstone diseases. Another field in which ultrasonic sound waves are widely used is maritime. By utilizing audible and ultrasonic sound waves, it is possible to locate the position of a moving object at a distance that poses an obstacle. When the obstructing object approaches the source, the frequency of the reflected wave increases, and when it moves away from the source, the reflected frequency decreases. This method is also quite functional in the detection of naval mines and submarines. Because ultrasonic waves have high frequency, they are particularly advantageous in underwater applications compared to audible waves. Since high frequency is directly proportional to short wavelength, it becomes possible for ultrasonic waves to travel longer distances.

How Ultrasonic Nozzles Work

The tip of ultrasonic nozzles containing piezoelectric transducers that provide high-frequency vibration moves up and down thousands of times per second, helping to perform the coating application quickly. The thin liquid film applied to the tip of ultrasonic nozzles creates capillary waves. The width of these waves can be regulated with the ultrasonic generator, and when capillary waves can no longer carry themselves after a certain point, they create micro-sized liquid droplets. Unlike high-pressure needles, ultrasonic nozzles are not based on applying pressure to liquid and passing it through a small opening. Instead, liquid is transferred through a larger opening without applying pressure, and the liquid is atomized with the help of ultrasonic vibrations in the nozzle. High-strength titanium alloys used in the manufacture of nozzles make these materials highly resistant to possible chemical reactions. Elements activated by electrical power are housed in a sealed case that protects the components contained in the nozzle from external factors. Nozzles are designed so that the liquid contacts only the titanium within it.

Sectors Using Ultrasonic Coating Technique

The glass manufacturing sector, which can be subdivided into branches such as lenses, touchscreens and solar panels, is at the forefront of fields where ultrasonic coating technique is widely used. Ultrasonic spray coating, offering an effective alternative to powder and pressurized spraying, has become preferred especially for flat glass coatings. Since this process does not require high vacuum, it is particularly widely used in solar panel production. Besides this, ultrasonic spray coating technique is utilized in microscope, camera and telescope lenses and in the manufacture of protective eyewear. Thin film coatings at nano and submicron levels are another area where ultrasonic coating is preferred. Polymer and paint thin film coatings are created in medical ultrasonic biosensors. The ultrasonic coating system, which facilitates complete control over flow rate and sediment volume, provides ease in creating a very thin and uniform layer.

Advantages of Ultrasonic Coating Technique

Ultrasonic spray technology continues to replace old-style coating techniques in many sectors with its innovative features. Being more easily controllable compared to traditional coating methods is one of the advantages that makes ultrasonic spray coating stand out. The ease of controlling the coating compared to traditional techniques such as immersion and rotational coating stems from the very low pressure required by ultrasonic coating and its use of a slow-speed spray. The slow-speed performance of the spraying process prevents excessive overspray and splashing, minimizing waste generation and thus enabling an environmentally friendly and economical coating process. Because it can operate at very low pressures, non-clogging nozzles can self-clean and can be used in harmony with nozzles having different functions. Coatings performed with ultrasonic spray allow for new application techniques. Unlike many coating methods, ultrasonic nozzles show positive performance in operations requiring very low flow rates. At the same time, even when the spraying process is stopped, the ultrasonic activity of the nozzles keeps all particles suspended in aligned fashion. Thus, particles can create uniform distribution in thin layers.

Future of the Ultrasonic Coating Market

The ultrasonic coating market showed significant growth in recent years across the world, particularly in developed countries. Many large companies in the sector expanded their product portfolio by acquiring smaller companies. In a report published in 2015, we see that ultrasonic coating production was 48.6% from North America, followed by Asia with 29% and Europe with 17%. The growth trend in the sensor, glass, textile and fuel cell sectors where ultrasonic coating technique is used strengthens the growth prospects of companies engaged in production based on this technique. The global ultrasonic coating technique market, which reached USD 15.32 billion in 2022, is expected to rise to USD 27.43 billion in 2028.   Sources • https://www.sono-tek.com/ultrasonic-coating/ultrasonic-spray-benefits/ • https://www.sono-tek.com/ultrasonic-coating/how-ultrasonic-nozzles-work/ • https://www.britannica.com/science/ultrasonics • https://flypaper.soundfly.com/discover/ultrasonic-animals-that-vocalize-at-frequencies-beyond-our-hearing-range/ • https://cheersonic-liquid.com/en/portfolio-items/ultrasonic-spray-coating-system/ • https://cheersonic-liquid.com/en/medical/biological-sensor-coating/ • https://microspray.com/ultrasonic-spray-nozzles-work/ • https://rivercountry.newschannelnebraska.com/story/46355377/ultrasonic-coating-systems-market • businessresearchinsights.com/market-reports/ultrasonic-coating-systems-market-100279 • Images by: pixabay.org     Compilation and Translation: Murat Soygür