What is the difference between polyurethane high pressure foaming machine and conventional foaming machine?

What is the difference between polyurethane high pressure foaming machine and conventional foaming machine?

Polyurethane high pressure foaming machine and conventional foaming machine (usually referred to as low pressure foaming machine) play an important role in polyurethane foaming process, but they have significant differences in working principle, equipment structure, application scenarios and foaming effect. The differences between the two devices will be explored in detail in several dimensions.

1. How it works

High pressure foaming machine:

The working principle of the high pressure foaming machine is to accurately measure and mix polyurethane raw materials 

(isocyanates and polyols) through high pressure. The high pressure pump pressurizes the raw material to 100-200bar (or even higher) 

and then mixes it instantaneously through the high pressure mixing head. Due to the effect of high pressure, the raw materials collide 

violently in the tiny chamber of the mixing head to achieve full mixing, and then rapidly ejected to form foam.

Conventional foaming machine (low pressure foaming machine) :

The working principle of the low-pressure foaming machine is relatively simple, and the raw material is transported to the mixing head

 through a low-pressure pump, and the mixing pressure is usually between 5-30bar. The raw materials are mixed in the mixing head by

 mechanical stirring or static mixer, the mixing effect is relatively weak, and the foaming speed and uniformity are not as good as the 

high pressure foaming machine.

2. Equipment structure

High pressure foaming machine:

The structure of high pressure foaming machine is complex, mainly including high pressure pump, high pressure mixing head, precise 

metering system, temperature control system and so on. The high pressure mixing head is the core component, which is designed to 

withstand high pressure and achieve instantaneous mixing of raw materials. In addition, high-pressure foaming machines are usually 

equipped with automated control systems that can precisely control the ratio of raw materials, mixing time and foaming volume.

Conventional foaming machine (low pressure foaming machine) :

The structure of low pressure foaming machine is relatively simple, mainly including low pressure pump, mixing head, metering system

 and temperature control system. The design of the mixing head is relatively simple, usually using mechanical mixing or static mixer, 

the mixing effect depends on the strength and time of the mechanical mixing. The low pressure foaming machine has a low degree of 

automation and relatively simple operation, but the accuracy and efficiency are not as good as the high pressure foaming machine.

3. Application scenario

High pressure foaming machine:

The high pressure foaming machine is suitable for occasions with high foaming quality requirements, such as automotive interior, 

refrigerator insulation layer, building insulation materials, etc. Because the high pressure foaming machine can realize the accurate 

measurement and instantaneous mixing of raw materials, the foaming effect is uniform and fine, and the foam density and strength 

are controllable, which is suitable for large-scale and high-precision production.

Conventional foaming machine (low pressure foaming machine) :

The low-pressure foaming machine is suitable for occasions where the foaming quality is not high, such as low-end insulation 

materials, packaging materials, simple fillers, etc. Due to the weak mixing effect of the low-pressure foaming machine, the foaming 

speed and uniformity are poor, which is suitable for small-scale and low-precision production.

4. Foaming effect

High pressure foaming machine:

The high pressure foaming machine can produce uniform and delicate foam, foam density and strength can be controlled, foaming 

speed is fast, and production efficiency is high. Due to the instantaneous mixing effect of the high-pressure mixing head, the raw 

materials are fully mixed, the bubbles are evenly distributed during the foaming process, and the foam quality is stable.

Conventional foaming machine (low pressure foaming machine) :

The foam quality produced by the low-pressure foaming machine is relatively poor, the foam density and strength are not easy to 

control, the foaming speed is slow, and the production efficiency is low. Due to the weak mixing effect, the bubble distribution is not 

uniform during the foaming process, the foam quality is unstable, and the problem of thick bubble and unequal density is easy to 

appear.

5. Cost and maintenance

High pressure foaming machine:

The equipment cost of high pressure foaming machine is high, and the maintenance cost is relatively high due to the complex 

structure. Core components such as high-pressure mixing wear out faster and require regular replacement and maintenance. In 

addition, the high energy consumption of the high pressure foaming machine is higher, and the operating cost is larger.

Conventional foaming machine (low pressure foaming machine) :

The equipment cost of low pressure foaming machine is low, the structure is simple, and the maintenance cost is also low. Mixing and 

first-class components wear slowly and maintain less frequently. Low pressure foaming machine has low energy consumption and low 

operating cost.

6. Operation and control

High pressure foaming machine:

The high pressure foaming machine is usually equipped with an automated control system, which is complex in operation and 

requires professional and technical personnel to operate and maintain. The control system can precisely control the ratio of raw 

materials, mixing time and foaming amount to achieve high-precision production control.

Conventional foaming machine (low pressure foaming machine) :

The operation of the low-pressure foaming machine is relatively simple, the degree of automation is low, and it is usually operated by 

ordinary workers. The precision of the control system is low, the production control is relatively rough, and it is suitable for the 

occasions where the production accuracy is not high.

Sum up

There are significant differences between polyurethane high pressure foaming machine and conventional foaming machine in working

 principle, equipment structure, application scenario, foaming effect, cost and maintenance, operation and control. The high pressure 

foaming machine is suitable for large-scale, high-precision production with high foaming quality requirements, while the low pressure 

foaming machine is suitable for small-scale, low-precision production with low foaming quality requirements. The choice of foaming 

machine depends on the specific production needs and budget.