Views: 0 Author: Site Editor Publish Time: 2026-08-13 Origin: Site
Producing high-quality roof waterproof coatings requires more than simply mixing different raw materials together. Depending on the formulation, manufacturers may need efficient bulk mixing, high-speed dispersion, vacuum processing and a reliable method for discharging relatively viscous materials.
To meet these requirements, Karvil Machinery recently completed a 250L vacuum multi-function mixer for a customer in Uruguay. The equipment was designed specifically for roof waterproof coating production and integrates low-speed mixing, high-speed dispersion, vacuum processing and hydraulic lifting into one compact system.
This project demonstrates how the right mixer configuration can be tailored around the actual material and production process rather than relying on a standard machine.
Roof waterproof coatings can contain a combination of liquid components, powders, fillers, pigments and functional additives. These materials need to be properly incorporated and dispersed to achieve a consistent final product.
A conventional agitator may be suitable for simple liquid blending, but more demanding coating formulations can require additional processing capabilities.
Typical challenges include:
Maintaining uniform mixing throughout the batch
Dispersing powders and additives effectively
Handling relatively viscous materials
Controlling the mixing speed for different processing stages
Processing under vacuum
Removing the finished material efficiently from the mixing vessel
For this reason, the Uruguay project uses a multi-function mixing and dispersion system instead of a single conventional agitator.
The Karvil system has an effective working volume of 250L and uses two mixing vessels. The vessels are manufactured from SS304 stainless steel and have an internal diameter of 750 mm and an internal depth of 700 mm.
The configuration includes:
250L effective working volume
SS304 mixing vessels
Low-speed frame agitator
PTFE wall and bottom scrapers
High-speed dispersing system
Two toothed dispersing discs
Vacuum system
Hydraulic lifting system
Electrical and hydraulic controls
Hydraulic pressure discharge system
The mixing system and dispersing system operate independently, allowing the customer to select the appropriate operating conditions for different stages of the formulation process.
The mixer is equipped with an 11 kW low-speed motor and a frame-type agitator.
The mixing speed can be adjusted from 5 to 50 rpm through variable-frequency control.
The frame agitator is equipped with removable PTFE wall and bottom scrapers. These scrapers help maintain material movement near the vessel wall and bottom while also making the scraper components easier to remove for maintenance.
For high-viscosity coating formulations, controlled low-speed mixing is important because the material needs to circulate throughout the vessel rather than simply being moved around the center of the tank.
In addition to the low-speed agitator, this system includes a separate 15 kW high-speed dispersing motor.
The disperser provides a speed range of 0–1,440 rpm and uses two toothed dispersing discs made from SS304 stainless steel.
The combination of high-speed rotation and toothed dispersing discs provides a dedicated dispersion stage for formulations that contain powders, fillers, pigments or other ingredients requiring intensive mixing.
The system uses one dispersing shaft with two dispersing discs, while the disc diameter is configured within the range of 140–180 mm.
The 250L mixer is equipped with a complete vacuum system consisting of a vacuum pump, buffer tank and metal flexible hose.
The specified vacuum level is at least -0.09 MPa.
The closed top cover also includes a dedicated vacuum connection, vacuum gauge and exhaust connection, allowing the operator to control the vacuum process from the control system.
A particularly important feature is the vacuum buffer tank, which is designed to help prevent vacuum pump oil from flowing back into the mixing vessel.
This type of protection is especially valuable when processing products where contamination control is important.
The mixing and dispersing assembly is mounted on a hydraulic lifting structure.
The hydraulic cylinder provides a lifting stroke of up to 800 mm, allowing the mixing head to be raised from the vessel.
This configuration provides easier access to the mixing vessel and internal components for operation, inspection and maintenance.
The equipment also incorporates a safety interlock: the crossbeam cannot be raised while the mixing vessel remains under vacuum.
Mixing is only one part of the production process. Once a batch of waterproof coating has been completed, the finished material also needs to be discharged efficiently.
For this project, Karvil supplied an SXDYJ-250 hydraulic pressure discharge machine together with the mixer.
The pressure discharge system uses a hydraulic cylinder and matching pressure plate to push the material out of the mixing vessel.
One of the main advantages of this project is that the customer receives more than a basic mixing vessel.
The complete system brings together:
Mixing → Dispersion → Vacuum Processing → Hydraulic Lifting → Pressure Discharge
This integrated approach can simplify the production process and reduce the need to transfer material between different processing machines.
For coating manufacturers, this can be particularly useful when process consistency, equipment footprint and material handling are important considerations.
The mixer uses a 380V, 50Hz, three-phase power supply and combines electrical and hydraulic control.
Variable-frequency drives are used for motor starting and speed adjustment.
The control panel provides control and monitoring for:
Mixing start/stop
Mixing speed
Dispersion start/stop
Dispersion speed
Vacuum function
Temperature
Rotational speed
Emergency stop
The electrical system uses Schneider electrical components, while the specified motor is a Siemens Bede motor.
The variable-frequency drive also provides protection against overload, overcurrent, overvoltage, leakage and phase loss.
Safety was also considered during the design of the system.
The equipment includes an emergency stop function that immediately stops operation when activated.
The system also incorporates:
Vacuum lifting interlock
Vacuum oil backflow protection
Variable-frequency drive protection
Emergency stop
Speed monitoring
Temperature monitoring
Different coating formulations require different mixing solutions.
At Karvil Machinery, we do not simply select a mixer based on batch volume. Our engineers consider factors such as:
Material characteristics
Viscosity
Powder content
Required dispersion intensity
Batch size
Vacuum requirements
Heating or cooling requirements
Discharge requirements
Production process
Based on these factors, the mixer can be configured with different agitator designs, motor powers, dispersion systems, vacuum systems, lifting mechanisms and discharge solutions.
The Uruguay project is one example of how a standard mixing concept can be developed into a customized industrial mixing system based on the customer's actual application.
Don't choose a mixer based on capacity alone.
Tell us your material, viscosity, batch size and production requirements. Karvil's engineers can help you determine the right mixing and dispersion configuration for your application.
Your material is unique. Your mixing solution should be too.
