weight-loss feeder

A loss-in-weight feeder is a precise dosing system for bulk materials. It measures the mass flow of the product in real time via the weight loss of the storage container. This allows powders, granulates or mixing components to be fed continuously and with high accuracy – a basic requirement for consistently high mixing quality.

While liquids are relatively easy to dose, powdered materials pose greater challenges. Different bulk densities, flow properties and particle sizes influence the dosing behaviour. Gravimetric systems automatically compensate for these fluctuations: sensors continuously measure the weight, and a control system adjusts the speed of the screw conveyor or rotary valve accordingly.

In modern production facilities – such as those involved in the continuous manufacture of powder formulations – the loss-in-weight feeder is the central component for stable process control. It enables several raw materials to be fed into the mixer simultaneously in the correct proportions. Even the smallest dosing deviations are detected and corrected, ensuring consistent homogeneity.

To maintain measurement accuracy, the inlet and outlet connections are flexibly mounted, usually using folding sleeves. Inside, a rotating rake tool ensures that the product is evenly loosened so that the dosing screw can always convey a homogeneous powder. This keeps the material flow stable and prevents the weighing signal from being distorted.

The dosing performance remains precise even with short refill cycles. During the filling phase, the screw operates at a constant speed ("blind phase") until the system returns to the target weight. This proven method ensures reproducible process conditions.

amixon® frequently uses gravimetric dosing systems of this type in conjunction with continuous mixers. Only when the mass flows are precisely controlled can homogeneous mixtures of the highest quality be achieved – especially with sensitive or high-priced powders.