Perlite is a volcanic glass formed when lava cools very rapidly, trapping small quantities of water. After mining, crude perlite rocks are crushed, dried, milled and screened to different grades. When graded perlite is heated to about 900ºC, the material undergoes its expansion process; the trapped water vaporizes and creates countless tiny bubbles in the softened glassy particles. In this process perlite expands 10-20 times its original volume changing from a rock to a lightweight material with cellular granules of porous nature.
Specific granulometries and special qualities are selectively chosen by Imerys for its Horticultural Raw Perlite production. The procedures followed during this production are strictly controlled in order to ensure a material of high quality with uniform and unique properties suitable for the horticultural application it will be used for.
No matter what the kind of horticultural application, Imerys guarantees superior Horticultural Raw Perlite material for expansion so as to provide a nearly ideal air-water relationship for superior plant growth and root development.