Labotek MCWeight Systems - Self-Regulating Gravimetric Dosing Technology for Extrusion Processes
Developed by Labotek, the MCWeight systems are gravimetric dosing solutions based on the loss-in-weight principle, designed for extremely precise and automatic dosing of additives, masterbatch, and similar supplementary materials in extrusion lines. In continuously operating extrusion processes, MCWeight systems play a critical role in maintaining constant additive ratios, protecting product quality, and achieving raw material savings.
Unlike conventional volumetric dosing units, MCWeight continuously weighs the dosed material and automatically adjusts the feeding speed through a self-regulating control loop. As a result, variations in material bulk density, granule geometry, or process fluctuations do not affect dosing accuracy. Since the system operates on true mass flow, stable additive ratios are guaranteed even during long production runs.
Operating Principle - Self-Regulating Loss-in-Weight Dosing
At the core of the Labotek MCWeight systems is an integrated weighing module combined with the loss-in-weight principle. Using a weighing unit equipped with two load cells, the system continuously measures the weight loss in the dosing hopper. Based on this weight loss, the instantaneous mass flow is calculated and the screw motor speed is automatically adjusted.
This design ensures that:
The dosing process continuously self-calibrates
True mass flow remains constant even if material density changes
Additive ratios in the extrusion line are kept stable
Continuous and reliable production is achieved without operator intervention
The MCWeight system is automatically refilled via an integrated pneumatic knife gate located at the upper flange. During refilling, the system continues to manage the process without interrupting gravimetric control. This feature provides a major advantage for extrusion lines operating continuously.
Technical Specifications and Numerical Data
The main technical and numerical specifications of the Labotek MCWeight systems, as listed in the catalog, are summarized below.
Operating principle
Fully gravimetric loss-in-weight dosing
Integrated weighing module with dual load-cell design
Capacity options
100 kg/h
500 kg/h
1000 kg/h
These capacity levels provide flexible solutions for different extrusion lines and additive usage ratios.
Power supply
80-260 Vac, 50/60 Hz
Integrated power unit with automatic voltage selection
Maximum power consumption
150 W
Operating temperature (mechanical unit)
-20 °C to +160 °C
Operating temperature (control unit)
-20 °C to +70 °C
Weighing hopper volume
40 liters
Control and operation
Menu-guided user interface
Standard languages: English and German
Other languages available on request
Input signals
Potential-free start input
24 Vdc start signal
Output signals
Alarm output
Data storage and monitoring
Internal memory for static change logging
Dynamic data logging and centralized monitoring via MC-LAN software
Communication infrastructure
Standard Ethernet connection
Optional analog output card
Optional Profibus communication card
Thanks to this technical configuration, MCWeight systems can operate either as standalone units or be easily integrated into centralized automation systems.
Mechanical Design and Structural Features
MCWeight systems feature a robust mechanical design intended for long-term and reliable operation in industrial environments. The main structural components shown in the catalog include:
Transparent inspection window for visual process monitoring
40-liter gravimetric weighing hopper
Heavy-duty support frame and housing
Upper feed inlet with pneumatic knife gate
High-precision screw and motor feeding unit
Load-cell junction box and safety fasteners
The screw and motor system is engineered to deliver smooth and stable material flow even at high throughput rates. This design significantly improves process reliability in film, pipe, and profile extrusion applications where additive dosing accuracy is critical.
Application Areas
Labotek MCWeight systems are primarily used in the following applications:
Plastic extrusion lines
Film and sheet extrusion
Pipe and profile production lines
Continuous processes requiring additive and masterbatch dosing
High-precision additive feeding applications
In processes where additive ratios are controlled at very low percentages and process stability is critical, MCWeight delivers far more reliable results than volumetric systems.
Industrial Advantages and Process Benefits
The key advantages provided by Labotek MCWeight systems include:
High accuracy through fully gravimetric dosing
Operation independent of material density variations
Reduced additive and masterbatch consumption
Stable and repeatable product quality
Fast product and color changeovers
Low maintenance requirements and long service life
Continuous and safe operation in extrusion lines
With these characteristics, MCWeight stands out as a strategic dosing solution for plastic extrusion plants operating continuously and where precise additive control is essential.
