sSORB orange indicating silica gel is a Type A, narrow pore silica gel in bead form, impregnated with a cobalt-free moisture indicator. Orange silica gel is typically specified where a visual moisture check is wanted without the cobalt chloride indicator that colors blue silica gel. Two indicator chemistries are offered. The orange to green grades turn from orange to green as they adsorb water; the change typically begins as the moisture content passes about 6% by weight and is complete at about 14%, and a bright green bead is saturated. The orange to clear grade loses its color as it loads, and a clear bead is saturated. Within each bead, a network of interconnecting pores with a nominal opening of 20 to 30 angstroms holds water by physical adsorption and by capillary condensation. The gel can remove moisture at temperatures up to 220°F, though it typically performs best near room temperature, about 70 to 90°F, and at a relative humidity of about 60 to 90%. The grades share the same pore opening, minimum water adsorption capacities, bulk density, and size qualification, and differ in bead size and in the indicator. Interra Global's silica gel line also carries white silica gel, the non-indicating grade, and blue silica gel, the cobalt chloride indicating grade.
Chemical Formula, orange to green: SiO₂ · nH₂O + C₂₅H₃₀N₃Cl or SiO₂ · nH₂O + C₂₀H₁₄O₄
Chemical Formula, orange to clear: SiO₂ · nH₂O + (NH₄)₂SO₄ · FeSO₄ · 6H₂O
TYPICAL APPLICATIONS
sSORB orange indicating silica gel is typically used in:
- Compressed air dryers
- Industrial gas drying
- Dehydrating breathers
- Packaged goods, other than products for consumption such as food and pharmaceuticals
- Drying and storage of flowers and seeds
SIZES AND PACKAGING
- sSORB AY13B, 1 to 3 mm beads, orange to green
- sSORB AY25B, 2 to 5 mm beads, orange to green
- sSORB AOC25B, 2 to 5 mm beads, orange to clear
The orange beads ship in 55 lb (25 kg) bags and in super sacks. Other containers are quoted on request. Interra Global supplies these grades as a bulk indicating desiccant under whichever name a specification uses, orange silica gel, yellow silica gel, color changing silica gel, or self-indicating silica gel, and its staff answer questions on bead size and packaging when asked.