PETRA Expanded Microspheres (EXP Series) are advanced lightweight inorganic mineral microspheres engineered to deliver superior weight reduction, thermal insulation, and formulation efficiency across a wide range of industrial applications. Manufactured using advanced expansion technology, these microspheres feature a closed-cell structure that provides low density, high thermal stability, excellent flowability, and dimensional stability. PETRA EXP Series helps reduce material consumption, improve workability, enhance insulation performance, and optimize processing efficiency. These versatile lightweight fillers are widely used in dry-mix mortars, construction chemicals, plasters, putties, coatings, polymer compounds, composites, insulation systems, and other industrial applications requiring lightweight and high-performance formulations.