Powder Coating Feeding Systems – Box Vs Hopper Feed Systems

When you are considering a powder coating equipment solution one of the key components is how the powder coating is delivered to the powder coating gun. The method of delivery impacts the portability of the powder coating equipment along with the finish that the powder coating gun delivers. Will cover the two main ways to deliver powder coating and the benefits and drawbacks of each in this article.

Powder Coating Delivery Method 1  – Vibratory Box (Box Feed Powder Coating Systems)

Box feed powder coating systems fluidize powder by a shaking motion. This shaking motion causes the powder coating to become suspended in air which is then supplied to the powder coating gun and applied appropriately. The major benefit to a box feed powder coating system is its convenience.  The powder coating can be fed directly from a box eliminating the need to transfer powder. Additionally, it allows for easy changing of powder coating colors. It is often the ideal option when you need to change powder coating colors frequently and allows for flexibility. The only slight drawback to box feed powder coating equipment is that it may not supply powder to the powder coating gun as fluidized. This can result in a slight reduction in the finish quality. It can also lead to the need to occasionally clean out the powder coating gun as the powder coating may become clotted requiring proper cleaning.

Powder Coating Delivery Method 2 – Fluidized Bed Hopper Feed Systems

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. 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. 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.

When a Vibratory Box Fed Powder Coating System is Right

• Powder coating where color change is needed – this is often the case for a powder coating job shop where multiple colors will be used in a given day; the vibratory box will allow ease changing of colors and powders
• You work with standard powders – Vibratory boxes work perfectly if your powder is all uniform in particle size
• Smaller powder coating runs – If your only doing a box of powder occasionally a box fed powder coating system is perfect for your needs

When a Hopper Feed Powder Coating System is right

• 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

Ultimately the decision between fluidized bed hoppers and box fed powder coating systems is critical to ensure you have a system that will perform well for your powder coating needs.