Expandable Microspheres China (Thermally expandable microspheres) are thermoplastic expandable microspheres, a type of thermal expansion microcapsule with a core-shell structure. They are composed of a thermoplastic polymer shell encasing a low-boiling solvent (liquid alkane gas or other compounds). Their diameter is generally between 10 and 50 μm. Upon heating, their volume can expand rapidly to several times their original size. After cooling, the microspheres can maintain their expanded volume without shrinking back.Expandable Microspheres China, as an ideal lightweight filler and physical foaming agent, have been widely used in various fields.
No open-cell pores, avoiding the issues of uneven pores, rupture, and poor resilience associated with ordinary foaming agents. Their complete spherical structure ensures good mechanical properties.
The thermoplastic shell has excellent pressure resistance, capable of withstanding up to 300kg/cm2 of pressure. Expandable Microspheres China have good resilience that can withstand multiple cycles of pressure application and release without breaking.
After foaming, the volume can reach 40-80 times the original size. Expandable Microspheres China have an independent closed-cell structure that remains intact after foaming, with relatively uniform pore size, resulting in stable foaming performance.
Ordinary foaming agents may produce odors and residual volatiles during use and curing, whereas Expandable Microspheres China are non-toxic and non-polluting, providing safer performance. They can be used as environmentally friendly foaming agents in high-end and high-added-value products.
Expandable Microspheres China form an inflated, sealed cavity after thermal expansion, providing excellent insulation properties. When added to polyurethane, phenolic resin, coatings, and other materials, they offer superior thermal insulation, sound insulation, vibration damping, flame retardancy, and electrical insulation effects.
They can be used for processing non-woven fabrics. By mixing Expandable Microspheres China with resin materials to form a slurry and impregnating it into non-woven or fiber materials, followed by drying and foaming, thickness can be increased, or lightweight materials can be formed.
Adding Expandable Microspheres China to sandwich materials can give composite materials elasticity, reduce density without reducing strength, making them excellent lightweight filling materials.
In coatings, Expandable Microspheres China can increase coating thickness and improve surface characteristics after coating, drying, and heating to foam, such as creating a three-dimensional effect, suede effect, matte texture, etc.
Expanded microspheres can be mixed with many thermosetting resins to make low-density molded products, such as silicone, unsaturated resin, epoxy resin, phenolic resin, etc.
For example, for shoe sole injection molding, they can reduce sole density and increase resilience.
Different types of expandable microspheres may vary in specific applications. Selection should be based on actual needs and material properties. Their performance may also be affected by various factors such as polymer composition, internal gas type, chemical exposure, external pressure, and heating speed. In some new fields, research and exploration on the applications of Expandable Microspheres China are continually being conducted.