Ultrasonic Atomization For Coatings
Ultrasonic Atomization For Coatings. Ultrasonic Atomization technology is a very high-tech atomization technique that is used for spray coating. The liquid is fed through the center of the nozzle, allowing unrestricted flow out of the orifice, and creating a thin liquid film on the surface of the nozzle. As this surface is set to vibrate at a certain frequency perpendicular to the film, the liquid absorbs the vibrational energy and standing waves are created.
Incorporating a precise liquid delivery system allows the thin liquid film to continue ejecting droplets with diameters defined by this equation. Due to the fact that atomization is only occurring on the vibrating surface, the amount of liquid atomized is dependent only on the rate that the liquid is delivered to the surface.
This soft spray is extremely useful in maximizing transfer efficiency to the devices and results in significant cost savings when dealing with expensive drug/binder combinations.
The soft spray also allows the droplets to be accurately directed towards the substrate using low pressure air shaping gas, typically nitrogen. Depending on the exact substrate and air shaping selected, the focused region can be anywhere between .25 mm wide up to 6 mm. The droplets created in this small spray plume are forced to wet out and create a thin film on the balloons. With low concentrations of drug/binder in solvent, it is very easy to scale down to the nanometer range thickness.