About Silica Gel Desiccant
Silica gel desiccant is a porous, amorphous form of silicon dioxide made into hard, translucent beads. Its vast internal surface adsorbs water vapour physically, so it can take up a large proportion of its own weight in moisture while staying dry to the touch and free-flowing. It does not react with the goods it protects and contains no free liquid.
This grade is designed for packaging and storage. Sachet converters, packers and exporters use it to control humidity inside cartons, containers, instrument cases and sealed packs, protecting goods from corrosion, mould, caking, label damage and condensation during sea or road transport. Bead size ranges are chosen to suit sachet filling machines and the volume of air to be dried, and beads are screened to keep dust and broken fragments low.
Silica gel works best at moderate to high relative humidity, which is typical of warehouses and shipping containers in humid climates. For drying inside resins and rubber compounds, our calcium oxide and molecular sieve grades are more suitable. Obsidian Minerals supplies silica gel desiccant from Gujarat with an SDS, Technical Data Sheet and batch Certificate of Analysis, and adsorption capacity, moisture and bead size are checked in an NABL-accredited laboratory. Bulk beads for converters and private-label packaging are available on request.
Typical specifications
| Parameter | Typical Value | Test Method |
|---|---|---|
| SiO₂ | ≥ 98 % | Internal method |
| Bead size ranges | 1–3 mm, 2–5 mm, 3–5 mm | Sieve analysis |
| Adsorption at 50 % RH, 25 °C | ≥ 20 % w/w | Internal method |
| Adsorption at 90 % RH, 25 °C | ≥ 30 % w/w | Internal method |
| Loss on heating | ≤ 2.0 % | Internal method, 150 °C |
| Bulk density | 0.65–0.78 g/cm³ | Internal method |
| pH (aqueous extract) | 4.0–8.0 | Internal method |
Typical values for guidance. Guaranteed limits are stated on the Technical Data Sheet and batch CoA. Adsorption values refer to freshly opened material.
Key features & benefits
High moisture capacity
Silica gel desiccant adsorbs a large share of its own weight in water vapour at the humidity levels found in warehouses and containers, giving long protection from a modest sachet size.
Chemically inert
Amorphous silica does not react with metals, textiles, electronics or most packaged products, and it contains no free liquid that could leak or stain goods during storage.
Hard, low-dust beads
Beads are hard and screened to remove fines, so they flow cleanly through sachet filling machines and leave little dust inside packs or on the products they protect.
Choice of bead size
Several size ranges are offered, letting converters balance adsorption rate, fill weight and sachet format. Smaller beads adsorb faster; larger beads suit bulk container and drum use.
Applications
Export cartons and containers
Used in cartons, pallets and container bags to reduce condensation, often called container rain, that damages goods and packaging during long sea voyages through changing climates.
Electronics and instruments
Placed in sealed packs and cases for electronic assemblies, optics and precision instruments to limit corrosion and fogging caused by humidity in storage and transit.
Leather, textiles and footwear
Added as sachets to boxes of leather goods, garments and shoes to reduce mould growth, odour, cockling and moisture marks during warehousing and long shipment.
Usage & handling
- Sizing: required quantity depends on pack volume, packaging barrier, climate and storage time; ask us for a sizing estimate.
- Fill sachets in a low-humidity area and seal them promptly to preserve capacity.
- Place sachets close to the goods inside a sealed pack; open packaging lets in fresh moist air.
- Store bulk beads in sealed bags; reactivation guidance is available on request.
Packaging & supply
- 25 kg HDPE bags for sachet converters and packers
- 1 MT or 1.2 MT jumbo (FIBC) bags
- Private-label and custom packaging on request
Frequently asked questions
How much silica gel desiccant is needed for a carton or container?
The quantity depends on the internal volume, how well the packaging seals, the moisture content of the goods and pallets, the climate on the route and the storage time. Share these details and we can provide a sizing estimate. Trial shipments with humidity indicators are the best way to confirm the amount.
Which bead size should I choose?
Bead size ranges of 1–3 mm, 2–5 mm and 3–5 mm are offered. Smaller beads adsorb moisture faster and fill small sachets evenly, while larger beads are easier to handle in bulk and suit large container bags. Your sachet machine and pack format usually decide the best option.
Can silica gel be reused?
Silica gel can usually be reactivated by heating to drive off adsorbed water, then cooled in a dry, sealed container. Reactivation temperature and time depend on the gel and the equipment, so please ask us for guidance. Sachet materials may not tolerate the temperature needed, so bulk beads are easier to reactivate.
Is silica gel suitable for drying rubber or plastic compounds?
Silica gel is designed for packaging and storage, where it adsorbs water vapour from the surrounding air. Inside rubber or polymer compounds, adsorbed water could be released again at processing temperatures. For compounding, our calcium oxide desiccant or molecular sieve powder is the better choice.