Electrostatics Explained
What is Electrostatics?
ke ≈ 8.988×109 N⋅m2⋅C−2
(Coulombs Law)
Electrostatics is an environmentally responsible way to apply coating materials, significantly increasing the quality of the finished product, while substantially decreasing powder/oil costs through more effective use of materials.
The aim is to eliminate wasteful over spray and put as much coating material on the target as possible. This is achieved by negatively charging atomized powder/oil particles so that they are attracted to the grounded work piece, opposites attract.
A charging electrode is located at the tip of the electrostatic generator head or atomizer. The powder/oil is atomized as it moves past the electrode, its particles become ionized – negatively charged. An electrostatic field is created between the charging electrode and the grounded work piece, the spray is concentrated within it.
The product to be coated (chips, tablets, etc.) is Grounded from contact within the rotating drum/wire belt flat chamber. When the coating material is released, it is attracted to the Grounded product. Due to the electrostatic attraction, coating material that would normally be lost ends up on the back and sides of the target product to produce a “wrap-around” effect.
When to use Electrostatics
When you want to achieve maximum transfer efficiency and minimize coating waste and dusting/misting emissions, while achieving maximum application wrap around effect, high production and high flow rates.
The Advantages
Up to 98% coating of all products, with greatly improved coating over traditional methods, less powder usage, cut down of dusting, cleaner working area and cleaner drum, all resulting in less line contamination.
Increased transfer efficiency and reduced over spray, which results in significant cost savings and reduced dusting/misting emissions. We build our system with safety in mind, with flexible, lightweight low voltage cable going to the generating spray head.
Typical Electrostatic Applications
• Pharmaceuticals: coating tablets granule formation
• Horticulture: powder onto seeds
• Agriculture: powder/liquids on potato or cattle feed
• Meat: fresh poultry and processed meats-powder & liquid flavouring
• Fish: oils & powder
• Breakfast Cereals: vitamins & flavouring in powder/liquid form
• Snacks, crisps, nuts, extruded and pasta pellets: powder & liquid spices
• Confectionery: powder onto mints, chewing gum, etc.
• Pet food: powder & liquid enhancers onto kibbles, biscuits & chew bars
• Dairy: starch onto cheese
• Bakery: oil & powder coating onto cakes, burger buns, etc.
Typical Savings from using Electrostatic Coating
| Method | Scarf Feeder | Paddle | Augur | SAS Electrostatics |
| Powder Saving | 10% | 0% | 0% | 10–45% |
| % Coverage | 65% | 25% | 20% | 98% |
| Drop Off | 60% | 80% | 80% | 5% |
| Line Contamination | 80% | 80% | 80% | 10% |
| Packer Contamination | 80% | 90% | 90% | 10% |
| Drum Contamination | 70% | 80% | 80% | 15% |
| Payback | ≤ 5 Years | ≤ 10 Years | ≤ 10 Years | 6 Months or less |
Method |
Scarf Feeder |
Paddle |
Augur |
SAS Electrostatics |
Powder Saving |
10% | 0% | 0% | 10–45% |
% Coverage |
65% | 25% | 20% | 98% |
Drop Off |
60% | 80% | 80% | 5% |
Line Contamination |
80% | 80% | 80% | 10% |
Packer Contamination |
80% | 90% | 90% | 10% |
Drum Contamination |
70% | 80% | 80% | 15% |
Payback |
≤ 5 Years | ≤ 10 Years | ≤ 10 Years | 6 Months or less |
