Getting the right liquid coating for snack foods, pet foods, and other products is already a difficult process. Finding a liquid coating system that can handle the coating efficiently and effectively is even more challenging. Some food manufacturers struggle to maintain the consistency of the coating while finding a clean application method that won’t cause shut-downs or require frequent maintenance. If you’re struggling with this problem, consider the following ways to reduce waste, improve efficiency and reduce maintenance costs in liquid coating using atomizing systems.
What are Atomizing Systems?
Most liquid coating systems use spray nozzles to evenly coat material as it moves through a mixer or conveyor. A rotary atomizing liquid coating system uses spinning disks to instead turn the liquid coating into a fine mist, which evenly coats the material as it falls through the coating chamber. The Mistcoater, including the T, TMX and SST models, is one such liquid coating system. These systems are preferred for many liquid coatings which can clog spray nozzles, such as those with high fat, sugar or salt content.
How Do Atomizing Systems Solve Liquid Coating Problems?
One common problem for liquid coating systems is overspray. In many cases, too much liquid coating is used in order to ensure that all particles receive some of the coating. If a particle receives no coating it can be missing key elements, while overspraying generally won’t harm the end product, so overspraying is usually preferred. However, this also causes waste and expenses that will build up over time. In addition, it can create slip-and-fall hazards when overspray touches walking surfaces, or generally create an unclean environment.
The Mistcoater uses a fully enclosed chamber, so the liquid coating does not escape and does not collect on surrounding surfaces. Since it creates a mist with increased surface area, it also requires less liquid to coat the product. Finally, the product falls through the coating chamber, so all sides of the particles are fully exposed to the liquid coating. By increasing the surface area of both the liquid and the solid, there is less waste and overspray.
Clogging may be the most common problem in liquid coating systems. Sugars and salts are prone to crystallization on the end of the spray nozzle, and fats are prone to congealing. Most liquid coatings use some combination of sugar, salt or fat solutions. Though not all of these mixtures will cause spray nozzles to clog, it can be difficult to predict which ones will. Or, changing the recipe slightly can cause clogging where a previous mixture did not.
When spray nozzles clog, multiple additional problems can occur; a buildup of backpressure can damage the liquid coating system, the liquid coating will be uneven, which can reduce the quality of the product, and excessive repairs and maintenance may be required to repeatedly deal with clogs. The Mistcoater helps to reduce and, in many cases, completely eliminate clogging problems, since it does not use spray nozzles. Instead, the liquid coating atomizes through the use of a rotating disk spinning at high RPMs. The liquid touches the disk and turns into a mist, which then coats the product as it falls through the enclosed chamber.
Inconsistency is another notable problem that can arise in liquid coating. Liquids are, by their nature, difficult to control. Ensuring that a liquid coating uniformly covers a particle once is difficult enough—it is even more difficult for millions of particles over a short space of time. Spray coating often only covers one side of the particle and requires additional steps for uniform coating. When working with a mixer, the spray coating must set very quickly, or the coating can be lost through the mixing action.
An atomizing liquid coating system like the Mistcoater works with, rather than against, natural forces to improve consistency. As the material falls through the coating chamber, it naturally turns, rather than remaining still, as it might on a conveyor. This exposes all sides of the material in a very short span of time, without requiring mixing action or additional steps. Instead of forcing a high pressure spray coating onto the particle and relying on absorption over time, the fine mist naturally attracts to the particle’s surfaces and pores. Since the mist is lighter than the liquid spray, it works its way into and onto the particles more easily, and dries faster.
Finding the right liquid coating equipment for your application requires careful consideration. Take a close look at the properties of the liquid coating, as well as the dry material. If you are struggling with these liquid coating problems, atomizing systems like the Mistcoater may be the ideal solution. To learn more about the Mistcoater and other liquid coating solutions, contact us.