Fluid Air coating equipment

Wurster Coating

Recognized for superior fluid bed layering, the Wurster process is often the choice for coating particles, spheres, granules, and tablets. Wurster technology uses an air stream to separate and suspend particles, then coats them using a spray nozzle positioned at the bottom of the fluid bed. This approach can produce very high-quality results with a variety of coating formulations, including aqueous and organic solvents, hot saturated solutions, and hot melts.

Top-spray solutions for the food industry

Top-Spray Coating for Food, Pharmacy, and More 

Spray coating can be applied to a wide range of ingredients and products—from chocolate and olive oil to fire retardants, as well as pharmaceutical and nutraceutical coatings. Top-spray systems can be ideal whether you need a general protective layer, where the exact application thickness is not critical, but requires consistent application.

Top-spray technology can also be used as a cost-effective alternative to Wurster coating, in which particles suspended in an airstream and are gently spray coated before they dry and drop back down into the product bed. Top spray coating nozzles are positioned above the product bed so that they spray directly onto products.

Top spraying provides the best results when the particle size distribution is narrow. However, products with a wide particle size distribution may be pre-agglomerated to allow for effective top spraying.

Fluid Air ultrasonic coating

Ultrasonic Coating for Fine Particles

A unique, relatively new approach, ultrasonic spray devices coat fine particulate substances, less than 100 micron, in a fluid bed. High-frequency vibration is used instead of high-pressure or compressed air to produce extremely small, uniform droplets, making this process ideal for high-precision coatings as well as vaporization, spray drying, and humidification.

When a liquid binder, coating material or other liquid inside an ultrasonic spray device vibrates at a specific frequency, capillary waves are produced on the surface of the liquid. During atomization, the capillary waves are transformed into droplets by increasing the amplitude until the peak of the wave forms droplets. The wavelength and subsequently, the droplet size, are determined by vibration frequency. High vibration frequency generates fine droplets and low vibration frequency generates coarse droplets. 


The distribution graph illustrates the average droplet size, in microns, at Dv 0.1, Dv 0.5, Dv 0.9, Dv 0.99 and the Dmax value at various pressures.

Fluid Air TABCOATER spray nozzle

Advanced Tablet Coating

Precise coatings are key to pharmaceutical and nutraceutical brands, impacting the look of the tablet or capsule, as well as the finished product's taste, odor, stability, ease of swallowing, and stability in the gastric environment.
Outstanding uniformity can be achieved more readily today, as complicated sugar coating processes of the past have given way to modern film and enteric coatings. Not only do these coatings provide greater flexibility, they allow a wider range of dosage forms, including pellets, granules, and drug crystals.


To ensure exceptional results, careful attention must be paid to the spray pattern, drop size, and nozzle spacing, as well as a wide range of other parameters. Fortunately, innovative nozzle and equipment designs help ensure consistent distribution of the coating material for higher-quality, more viable end products.

Check out our TabCoater and Wurster Coating products

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