What is the supercritical foaming material?

Publish Time: 2023-03-11     Origin: Site

With the development of science and technology, the supercritical foam forming technology has been widely used in various fields, and the process has gradually become a "Black Technology" and is slowly pushed to the market.



What is the principle of supercritical fluid microporous foaming?


A liquid with a temperature and pressure above the critical point is called a supercritical fluid (supercritical fluid, SCF). Supercritical fluid has unique properties, and its density, diffusion coefficient, solvation ability and other properties are very sensitive to change with temperature and pressure. The viscosity and diffusion coefficient arecloser to the gas, while the density and solvation ability are closer to the liquid.

The basic principle of microporous foaming of supercritical fluid is to use the dependence of gas solubility in the polymer on pressure and temperature, so that the polymer mixing system enters the thermodynamic unstable state in the cooling process, induce the formation of gas core, and then get the microporous structure.


Its foaming process can be divided into four stages:


1.The supercritical fluid into the polymer matrix, to reach the saturation state, forming a polymer / gas homogeneous system.

2.The temperature surge or pressure drop makes the gas in the homogeneous system to a supersaturated state that is the thermodynamically unstable state, thus causes bubble nucleation.

3. The gas spreads rapidly into the bubble nucleus and the bubble hole gradually grows up.

4. Rapid cooling, complete the finalization of the bubble hole structure.


Supercritical foaming technology or Critical EVA Materials are the most effective method to prepare microporous plastic in recent 20 years. The microporous structure here is similar to popcorn structure. In recent years, it has been widely used in various field.



What are the advantages of microporous plastic products?

1.High specific strength and high cost performance.

Can greatly improve the accuracy of the product size, shorten the product development cycle.

2. Significantly reduce the product residual stress.

It reduces the problem of improving the warping deformation and eliminates the shrinkage of the surface.

3.Cost saving  and environmental

It effectively saves raw materials, low cost of foaming agent, simple process of supercritical gas equipment and shortens the forming cycle of thin-wall products.

4.Low viscosity, easy to charge the die

The fluidity of the mixed sol can be enhanced by 20%~40%.



With their excellent lightweight, lower thermal conductivity, higher thermal conductivity, and noise reduction, supercritical foaming materials are widely used in transportation, sports equipment, ships, aerospace, furniture, decorations, toys, protective equipment and packaging industries.


For Shoes

Supercritical foam forming or

Critical EVA Materials

technology has gradually become the "black technology" in the field of shoe material, and the return rate of tpu shoe material with supercritical foam process is as high as 99%.


The Adidas boot running shoe, which bottom has a distinct granular feel and feels like foam, is made up of foamed thermoplastic polyurethane (E-TPU).


After pressurized heating, the original 5 mm particles can expand like popcorn. In this process, the volume of elliptical beads containing tiny closed bubbles will increase by 10 times.


These closed bubbles can give the foam microspheres excellent elasticity and required rebound effect, excellent shock effect.


For vehicle:


Supercritical foam materials used in automotive interior, rail transit and other fields, has its unique advantages:


  • No voc, no peculiar smell, completely solve the odor problem.

  • low as 30 kg/m3, which can reduce the weight of the vehicle

  • Lightweight and high strength, and the comprehensive mechanical properties are better than the traditional foaming materials.

  • Non-crosslinking, which can be recycled.

  • Excellent heat insulation, shock absorption, waterproof, sound insulation performance.


For New energy battery:


Supercritical foam POE is applied in the new energy battery heat insulation pad, which mainly plays the role of compensating the assembly tolerance and heat insulation buffer. At the same time, it also has light quality, low density, good creep performance, chemical corrosion resistance, voltage breakdown resistance, good thermal stability and other excellent properties.


For 5g industry applications:


Supercritical foam pp is applied in 5g radome, and its high strength meets the requirements of wind resistance and the requirements of outdoor photooxygen aging for more than 10 years. The surface is not hung with water, and the surface has a superhydrophobic layer similar to the surface of lotus leaf.


No matter what type of application you have or the style of foam required, our expert team will help you find the perfect material based on your demand. Please contact us at sales@shunhogroup.com.hk







ESD EVA Foam and Conductive EVA Foam in the PCB Industry

What is Supercritical TPU Material and Its Applications?

What is Supercritical EVA Material and Its Applications?

What Is XPE Foam Used For?

What is PET Felt Storage Solutions?