What are Perlites physical properties after expansion?
Perlite is a natural combination of mixed glassy silicates making it inert and resistant to chemical attack, except for hot concentrated alkali and hydrofluoric acid. It slows thermal conductance, is incombustible (melts above 2000°F) and has no buffering capability. Each Perlite particle resembles a glassy froth of bubbles. The internal structure consists of numerous tiny closed air-filled cells. This structure imparts lightness, natural insulating properties and limited compressive strength. Liquids cannot penetrate the cells. Perlite’s external surface is composed of broken bubbles surrounding the closed frothy cells and is open, extremely large and jagged. This irregular surface adsorbs or holds matter making it an ideal filtration media. In horticulture, Perlite’s surface helps keep planting media open and lightweight. It provides a pathway for air and moisture to access plant roots. It holds moisture and nutrients for assimilation by roots over time. Perlite’s high capillary acti
