Properties of polymers are often modified by quasi-spherical mineral fillers such as calcium carbonate or by highly anisotropic glass fibres for an efficient reinforcement or by foaming to reduce their density. Solid or hollow glass beads partly combine the advantages and also the drawbacks of those techniques allowing to modify mechanical, optical and thermal properties, density and cost of nearly all the polymers. Their adhesion to the polymer matrix can be optimized by sizing with coupling agents.
Moreover, glass beads have unique optical properties and can be modified by surface treatments to obtain electrical conductivity.
Consequently their application field covers a broad domain comprising polymer enhancement or lightening with hollow glass beads having a low density, syntactic foams used for buoyancy, reflective products for signs and marking, electrical conductivity for metal coated glass beads used in electronics.
Solid glass beads have a density of 2.5 g/cc, a high crush strength and a Moh hardness of approximately 6.