1️⃣ The Challenge of Fine Powder Feeding
Among all powder-handling applications, fine powder feeding is one of the most difficult to control.
Because of their small particle size, fine powders are highly sensitive to air and humidity,
making them prone to clogging inside hoppers and screw feeders.
Some typical examples include:
- Hygroscopic powders (e.g., silica, calcium carbonate)
- Electrostatically charged powders (e.g., titanium oxide, resin powders)
- Highly cohesive powders (e.g., metal powders, pharmaceutical powders)
These materials tend to block flow and cause irregular feeding performance.
2️⃣ How Clogging Happens
Clogging in fine powder feeders usually results from a combination of the following factors:
- Agglomeration – Particles stick together due to static charge or moisture, forming lumps.
- Adhesion – Powder sticks to the wall, gradually narrowing the flow path.
- Bridging – Powder forms an arch over the outlet and completely blocks the discharge.
Such issues not only stop the screw rotation but also lead to feeding inconsistency and quality instability.
3️⃣ Seiwa Giken’s Design Solutions
To solve these challenges, Seiwa Giken’s screw feeders incorporate several design innovations:
① Agitator Structure
A slowly rotating agitator inside the hopper keeps the powder gently moving,
preventing bridging before it occurs and ensuring smooth discharge into the screw.
② Polished Contact Surfaces
All stainless-steel contact parts are mirror-polished to minimize powder adhesion.
This reduces buildup during long runs and simplifies cleaning.
③ Use of Air Vibrators or Knockers
Depending on powder characteristics, light vibration or tapping is applied to dislodge stuck material.
For hygroscopic or cohesive powders, the combination of an agitator and air vibrator is particularly effective.
④ Stable Low-Speed Control
Seiwa Giken’s screw feeders offer precise low-speed rotation control,
enabling stable and consistent micro-feeding without pulsation.
👉 Learn more about Seiwa Giken’s Screw Feeders↓↓
4️⃣ Applications by Model
- Mini Screw Feeder
Specially designed for small-quantity feeding.
Ensures stable discharge even with fine or cohesive powders—ideal for R&D and test lines. - Standard Screw Feeder (20L Hopper Type)
Equipped with an agitator and optional air vibrator.
Provides stable feeding performance for large-volume or moisture-prone powders.
5️⃣ Detecting Early Signs of Clogging
Before complete blockage occurs, certain early warning signs can indicate that clogging has started:
- Gradual increase in motor torque or current
- Periodic fluctuation in discharge rate
- Powder level inside the hopper not decreasing
- Unusual feeding noise (intermittent “thump” or “rattle” sound)
At this stage, quick actions such as:
- Increasing agitator speed,
- Applying a short air pulse, or
- Temporarily increasing hopper vibration
can help restore smooth flow and prevent downtime.
By combining proper sensing and control, Seiwa Giken feeders achieve a design philosophy of
“Keep it moving before it stops.”
6️⃣ Conclusion
In fine powder feeding, stable performance cannot be achieved by screw rotation alone.
It requires a combination of mechanical design and hopper optimization
based on the powder’s unique properties.
