Rapid growth in the field of research of the world ocean in the middle of the past century was one of the basic incentives for development of the production of hollow glass microspheres (HGM).
The developers of the deep-submergence vehicles required state-of-the-art light-weight strong and water-resistant materials. Composites based on the HGM could, to a great extent, meet those requirements.
Technology for HGM manufacture is a complex physical-chemical and hydrodynamical process taking place in the course of forming of hollow bubbles from glass melt micro-particles by blowing. For this, our scientists have developed special fine-dispersion multi-component glass powders capable, in melted state, to form micro-particles of predetermined volume. An accurate dosage of gas generating component into powder provides blowing of the melted particles into microspheres with required wall thickness.
Hollow glass microspheres are thin wall bubbles with a diameter of 20-160 mcm and wall thickness of less than 2 mcm.
Strength of the microspheres is estimated by value of hydrostatic-pressure at which not more than 10% of the microspheres fail. It is natural that heavier microspheres with thicker walls are stronger.
The glass composition and almost regular shape of the microspheres provide a very high compressive strength, low water absorption, low heat conductivity and high chemical resistance.