Expandable microspheres are white microscopic spheres (average particle size is 10~30 μm and average density is approximately 1100 kg/m3) that comprise a thermoplastic shell encapsulating a low boiling point liquid hydrocarbon. When heated to a temperature high enough to soften the shell, the increasing pressure of the hydrocarbon will cause the microsphere to expand by 40 to 100 times. The microsphere ceases to expand when its inner pressure, shell tension and external pressure reach a balance. Its density after expansion can be lower than 30 kg/m3（0.03 g/cm3), making it the most lightweight application material in the world.

Expandable Microsphere Characteristics

Cost-saving:Expandable microspheres can be added to thermoplastic materials (such as PR, PP, PVC, PET, TPR, TPU, TPV, PA, and paper/board) as lightweight fillers and blowing agents. 1kg of expandable microspheres can replace 30kg of PVC or 25-30kg of paper fibers, drastically reducing product density to reduce volume and lower transportation cost. Applications: shoe soles, wood-plastic composites, auto parts, paper and board, nonwovens, coating, etc.

Low density:Since expandable microspheres can achieve a sharp reduction in density when heated, we can lower material density by 10% only by adding 3‰ of expanded microspheres and can reduce density by 10%-10% by adding 1% of unexpanded microspheres. Lowering product density without increasing its volume and thickness can help reduce energy consumption for cars and make lighter and more comfortable shoe soles. Applications： shoe soles, wood-plastic composites, auto parts, nonwovens, ultra-light clay, etc.

Surface modification:Small particle sizes such as 5μm can make a smooth surface, and large particle-sized microspheres can create relatively rough surface. Therefore, different particle sizes achieve different surface effects such as 3D and special cashmere surface, making the surface smooth, soft, and anti-skid. Applications: printing inks, leather coating, paper and board, etc.

Insulation:Microspheres are homogeneous closed-cell structure, so they have good insulation, sound proof, electrical insulation and low water permeability. Applications: wine corks, auto parts, crack fillers, silicone rubber, emulsion explosives, cables, etc.

Elasticity:Expandable microspheres are thermoplastic core-shell microscopic spheres that are very resilient. They can be compressed with a certain pressure and resume their original volume when the pressure is withdrawn. Applications: wine corks, auto interiors, silicone rubber, leather coating, cables, etc.