Polyurethane dosing units are the backbone of countless manufacturing processes, precisely metering and mixing chemical components to create high-quality PUR products. Explore how Cannon’s advanced dosing technology supports a wide range of industries with precision, safety, and reliability.
June 17, 2025
Polyurethane technology: understanding the basics
Polyurethane is produced by mixing two core components, often accompanied by one or more additives:
- Isocyanate (Component A)
- Polyol (Component B)
- Catalysts, blowing agents, fillers, and other additives (all optional)
Each component must be carefully stored, metered, and blended to start the chemical reaction that will become the flexible, rigid foam or solid plastic we are all familiar with.
Because the polyurethane blend is sensitive to heat, expanding faster at higher temperatures and slower at lower ones, consideration must also be given to the ambient temperature during production, especially for open mold processes.
A step-by-step look at the dosing unit process
Material storage and conditioning
Raw materials are stored in separate tanks, each equipped with temperature and pressure controls that maintain optimal conditions for each fluid, important for achieving predictable chemical reactions and end products of a consistent quality.
The metering process
From the tanks, the components are pumped using high-pressure axial piston pumps, gear pumps, or hydraulic-operated cylinders in the case of filled formulations. The flow rates and mixing ratios vary based on the applications, and the proportions must be strictly monitored and controlled. Flow meters and mass flow sensors, alongside servo- or frequency-controlled motors, ensure exact dosing.
The mixing process
The next phase is mixing. Here, the metered components are brought together using a “mixing head”. The method generally depends on the application, required output quantity, and formulation. There are two main types of mixing:
- High pressure: The components are sent to the mixing chamber at high velocity and pressure (usually 100-200 bar), creating turbulence that homogenizes them
- Low pressure: A mechanical stirrer or static mixer blends the components
Dispensing the mixture
Once blended, the polyurethane is dispensed directly into a mold, onto a surface, or into a cavity in a press or fixture. In some cases, like cavity filling in the automotive sector, this is done manually using a handheld head, but in most cases, the mixing head is mounted on a robotic system or CNC-controlled arm or motorized head carriers.
Curing and forming
The chemical reaction begins as soon as the components are mixed, generating heat and causing the mixture to expand or solidify. Curing times, processing temperature, and conditions depend on the specific formulation, application, and the environment.
Modern polyurethane dosing machines come with sophisticated control systems to optimize precision and safety:
- Temperature regulation ensures optimal fluidity and reaction conditions
- Ratio control guarantees the chemical balance of components
- Pressure monitoring maintains operational safety and equipment longevity
- Automated control systems (PLCs and HMIs) allow for recipe management, system diagnostics, and process automation
Industrial applications for PUR dosing technology
You may never have seen one of these dosing machines in action, but it is almost impossible not to have encountered a product made using one. They are behind the scenes, helping to make everyday life more comfortable and energy efficient, with applications including:
Why choose Cannon
Polyurethane history is Cannon history. We have been working with polyurethane since 1965, developing dosing machines and mixing heads, and pioneering processes and technologies that create higher quality products while cutting waste and energy consumption.
Our scope of supply extends far beyond the equipment and includes a comprehensive suite of services to support clients throughout the entire lifecycle of their projects, from planning and design to implementation, optimization, and maintenance. Our experienced team delivers tailored solutions to ensure project success at every stage.
Want to optimize your polyurethane production process?
Contact our specialists and find the perfect dosing unit for your needs.
