Glass microspheres; not exceeding 1mm in diameter

HS code 701820 covers the classification of glass microspheres, which are small, spherical glass particles typically less than 1 millimeter in diameter. These microscopic glass beads have a wide range of industrial and commercial applications, making them an important commodity in the global trade of specialty glass products. The production and export of glass microspheres is a significant component of the broader glass manufacturing industry, which plays a crucial role in various sectors of the economy, from construction and automotive to electronics and consumer goods.

Glass microspheres are primarily produced through a process known as flame attenuation. In this method, molten glass is forced through small orifices and then exposed to a high-velocity air stream, which causes the glass to form into tiny, uniform spheres. The spheres are then cooled and sorted by size to meet specific product requirements. Alternatively, some glass microspheres are created through a sol-gel process, where a liquid precursor is converted into a solid, porous material that is then broken down into small, spherical particles.

The production of glass microspheres requires several key inputs, including high-quality raw materials such as silica sand, soda ash, and other mineral additives. Specialized equipment, such as glass melting furnaces, orifice plates, and air-handling systems, are also essential for the manufacturing process. Additionally, energy sources, such as natural gas or electricity, are needed to power the production facilities and maintain the high temperatures required for glass melting and forming.

Glass microspheres produced under HS code 701820 are used in a variety of applications, including as fillers in paints, plastics, and rubber products, as well as in the production of reflective coatings and abrasives. These microspheres may also be used in the manufacture of 701912 Glass microspheres, which are larger in size and have different applications. The output of HS code 701820 can be an important input for industries covered by other HS codes, such as 320910 Paints and varnishes based on acrylic or vinyl polymers, dispersed or dissolved in an aqueous medium and 401699 Other articles of vulcanized rubber, n.e.s., among others.