soap drying plant
Drying is a crucial stage in bar soap manufacturing as it affects the physical properties of the soap. The optimum moisture content at the end of the drying stage determines better performance and productivity on the finishing line.
As a rule, soap paste at the end of the saponification process contains between 42% and 44% moisture content (MC). In drying plant, it can be dried to different degrees of MC:
- Toilet soap: 12% – 15% MC
- Translucent soap: 18% – 22% MC
- Laundry soap: 22% – 30% MC
Another way to measure the quality of soap at the end of the drying plant is with the Total Fatty Matter (TFM) variable. This variable determines the total amount of fatty matter that can be extracted from a sample of soap. A low TFM is associated with lower quality.
- Toilet soap: 77% – 80% TFM
- Translucent soap: 70% – 72% TFM
- Laundry soap: 62% – 70% TFM
The drying process consists of four steps:
SOAP FILTRATION AND FEED SYSTEM
The soap paste from the saponification step is pumped by the Filtration Pump through the soap filter to the feed tank.
The saponification step can be made using three different process: by boiler, by continous saponification plant or by Soap Crutchers.
The Soap Filter ensures that the soap paste leaving the saponification step is completely free from impurities or contaminants, protecting both the quality of the final product and the downstream equipment.
The Soap Feed Tank serves as a buffer, storing the filtered soap before it is pumped into the heating stage, ensuring a smooth and continuous production flow.
CRUTCHER
FILTRATION PUMP
SOAP FILTER
SOAP HEATING PROCESS
After the Soap Feed Tank, the soap paste is transferred by the Feed Pump into the Heat Exchanger, where it is efficiently heated.
During this stage, part of the water content evaporates, allowing the soap to begin its drying process before entering the Vacuum Spray Chamber (Atomizer).
This controlled heating ensures optimal soap consistency and prepares it for the final drying and finishing stages.
FEED PUMP
HEAT EXCHANGER
vacuum spray DRYING process
The soap paste is injected into the Vacuum Spray Chamber (Atomizer) by the Feed Pump. Inside the chamber, the carefully controlled combination of temperature and vacuum pressure enables the evaporation of water, achieving the desired moisture content in the soap. The separated steam is then extracted and condensed in the Barometric Condenser unit.
Inside the chamber, the semi-dry soap flakes are continuously scraped from the internal walls by rotating spatulas, allowing the dried soap to fall directly into the Plodder for further processing.
To optimize product recovery, Cyclone Separators are employed to collect and recycle soap particles carried by the vapors inside the vacuum spray chamber, ensuring efficient operation and minimal material loss.
VACUUM SPRAY CHAMBER
CYCLONE
PLODDER
STEAM CONDENSATION and vacuum system
All steam generated during the soap drying process is extracted from the Vacuum Spray Chamber (Atomizer) and Cyclones by the vacuum group, then directed to the Barometric Condenser.
Within the condenser, the steam is continuously transformed into water, ensuring efficient condensation, stable vacuum conditions, and smooth operation of the entire drying plant.
BAROMETRIC CONDENSER
VACUUM PUMP
Different Drying Plant configurations are available, depending on your production capacity (Kg/h) and the type of soap — whether for laundry or toilet soap bars.
We design, manufacture, and supply complete soap drying plants, fully tailored to your specific production requirements.
Contact us to discuss your project and find the most efficient solution for your soap manufacturing line.