The fluidized hopper feed system of powder coating delivery has a thin membrane at the base of a steel drum. This membrane is supplied air which causes the powder coating to be suspended (this is a simple explanation but is pretty close to the actual technology being used). The powder coating is then supplied to the powder coating gun.
When you look inside a hopper fed powder coating solution you will usually see the powder coating floating freely and it will appear almost like a fluid. It is this fine fluidized appearance that is the biggest benefit to the fluidized bed powder coating system. The powder suspension will often allow for a finer finish than a comparable vibratory box feed system. Due to the better preparation of the powder prior to being supplied to the gun, it will also reduce issues with plugging that sometimes can occur.
However, it doesn’t allow for simple changing out of the box of powder making it less effective for rapid powder coating color changes. It is also a bit heavier as a set up compared to a vibratory box system due to the extra weight of the steel drum that is included with a fluidized bed powder feed system. Additionally, you would need multiple hoppers if you want to accommodate multiple colors with the same system.
Advantages of Hopper-Fed Powder Coating Systems:
Conditions the powder
Fluidization helps remove moisture in humid environments by introducing clean, dry air from the bottom of the hopper
Mixes the powder
This is important if you are regularly spraying river textures or bonded metallic powders, or making a transition from one batch of the same powder to the next
Less chance of powder contamination
The hopper is sealed off from the outside environment and each hopper is typically only used for one type of powder
Less surging
Because the powder is better conditioned from fluidization, the pump picks up the powder more consistently and the gun delivers it more uniformly
Disadvantages of Hopper-Fed Powder Coating Systems:
Increased cleaning time
If you only have a couple hoppers for all your colors and textures, it can take a significant amount of time to switch between colors or textures
Cost & storage issues
Buying multiple hoppers to accommodate all your colors and textures is costly. Storing hoppers not in use or empty hoppers can be challenging or a waste of floor space, especially if you do not normally carry some common powders in inventory
Reduced throughput
Commonly having to move a hopper-fed gun around can slow you down, especially if you are working on something of great size or complexity
When is a hopper-fed powder coating system the correct choice?
When you are working with powder that has special characteristics like metallic particles of different density than other parts of the powder coating
Limited color uses – if you are using only a few colors the hopper fed system can often provide a fine finish at a better overall price
Recovering powder coating – If you are reclaiming powder coating you will need a hopper fed powder coating system to allow for proper blending of the virgin powder coating with the used powder coating
If you have any questions on powder coating guns or powder coating systems, please visit our "Powder Coating Guns" page or "Contact Us" page on our website.