Low pressure polyurethane foaming machines are widely used in various industrial fields such as self-skinning and soft foam due to their simple structure, convenient maintenance and high cost performance. During the use of customers, they often encounter some problems in equipment selection, parameter setting and operation optimization. Based on our technical accumulation and customer feedback, this article provides a centralized answer to the following technical questions.
Can a color tank be added to a low pressure machine?
You can add a color tank. But whether to add it is recommended to judge based on the color depth:
- Light-colored pigments : It is recommended to add them directly into the main material tank for color matching, which can effectively avoid color difference.
- Dark pigments : Suitable for using independent color paste tanks, which are injected into the mixing chamber through precise metering pumps. The color is more stable and is conducive to mass production.
What is the heating mechanism of the tank?
The Low pressure machine material tank adopts electric heating + cooling water automatic temperature control system :
Built-in electric heating tube to heat the raw materials in the interlayer; when the temperature exceeds the set value, the chiller will automatically inject cold water into the interlayer to help cool it down; achieve constant temperature control to avoid abnormal reactions of raw materials due to temperature fluctuations.
Is the motor controlled by a frequency converter?
Yes. Low voltage machines use variable frequency motors , controlled by inverters, which have the following advantages:
- Precise speed regulation to adapt to different mixing ratios;
- Soft start and stop to reduce mechanical shock;
- Energy saving and high efficiency, improving system stability.
What are the commonly used feed pump models?
The feed pump model commonly used for Low pressure machines is KCB83.3 , with a flow rate of about 160kg/min . This gear pump has stable operation, high pressure resistance, and easy maintenance, and is widely used in the transportation of medium-viscosity PU raw materials.
Is there a smaller Low pressure machine?
Yes. We offer a variety of miniature Low pressure presses , suitable for small batches, high-frequency, laboratory or manual molding customers.
What is the maximum power generation flow of the Low pressure machine?
The largest model we have ever customized has a foaming output speed of 10~15kg/s , which can meet the needs of continuous and efficient casting of large polyurethane products, such as large self-skinning workpieces or PU tires.
Is the mixing head in the flow range of 4–7kg/s a needle valve or a balancing valve?
The models in this flow range are usually equipped with a mixing head with a needle valve structure , which has a simple structure and fast switching, and is suitable for medium and high speed operation. The diameter of the mixing head is about 106mm , which can be further customized according to the mixing ratio and viscosity.
Can I add a fan to help dissipate heat from the host?
Although it is possible to add a fan, we do not recommend using an external fan . The reasons are as follows:
- It is easy to inhale dust, which will affect the life of the internal components of the host;
- The electronic components in the control box can work normally in an environment of 90-120°C ;
- If temperature control is required, we recommend using sealed liquid cooling or natural convection cooling structure .
For a 500g/s low pressure press with a filling system, how big is the hopper?
This type of system is equipped with a hopper volume of about 62L , with a stirring and insulation structure, suitable for continuous feeding of high-density filler composite materials.
What is the total power of the low voltage machine?
The total power of the 0-200g/s model is about 13kW , which is suitable for the continuous production of most self-skinning or glove-type PU products.
2.5-200g/s model, the power of each part is as follows:
- Main unit: 8.25kW
- Chiller: 1.75kW
- Feed pump: 3kW
What size air compressor is suitable for a Low pressure machine?
Recommended options:
- Three-phase 7.5kW air compressor (exhaust volume 1.0~1.2m³/min)
- Equipped with a 1 cubic gas storage tank , it can meet the gas supply needs of daily pneumatic valves, mixing heads and other control systems.
What are the usage and pressure requirements of nitrogen?
The recommended nitrogen pressure is P = 0.05MPa . Its main functions are: maintaining stable air pressure in the tank to prevent moisture absorption by raw materials; forming an inert atmosphere to avoid unnecessary prepolymerization reactions of the polyurethane system during storage or transportation ; and improving the safety and stability of equipment operation.
Summary: For equipment selection, please find a professional team
From flow selection, power matching, to heating and cooling, and accessories selection, we have provided customized Low pressure casting solutions for customers in many industries around the world. If you are looking for an efficient, stable, color paste-adding, and polyurethane equipment suitable for polyurethane soft foam, rigid foam , and self-skinning, please contact our engineers for one-on-one technical support.
