Lightweight Functional Fillers - Cenospheres

A recent addition to our product portfolio is functional filler materials / hollow microspheres.

Lightweight functional fillers are particle materials, which are added to a target matrix materials, usually, to decrease weight and lower costs. Simultaneously, the addition of such fillers can improve specific physical properties such as thermal and impact resistance, acoustic and thermal insulation properties, flexural, tensile and compressive strength, stiffness, packing ratio and abrasive properties, as well as viscosity. Such fillers can also reduce warpage, shrinkage, thermal expansion, and dielectric properties.

Currently, Riverside is offering natural hollow microspheres / cenospheres. A cenosphere is a lightweight, inert, hollow sphere made largely of silica and alumina and filled with air or inert gas, typically produced as a byproduct of coal combustion at thermal power plants.



  • Lightweight cement, plasters, stucco and other building products
  • Sealants, caulks, adhesives and fillers
  • Refractory, foundry
  • Acoustic insulation products
  • Thermal insulation and hi-temp coatings
  • Friction materials and abrasives
  • Composite Components (Thermosets, Thermoplastics, Elastomers)
  • Polyurethanes, Epoxy compounds
  • Explosives


  • Weight reduction
  • Faster cooling rates and reduced cycle times
  • Chemical Inertness
  • Dimensional stability
  • Thermal Insulation
  • Acoustical Insulation
  • Reduced thermal conductivity
  • Increased compressive, tensile and impact strength
  • Improved rheological properties

Available Particle Size

  • Standard: 500 µm, 300 µm, 150 µm, 125 µm
  • Custom : 100 µm, 75 µm