The high-quality, consistent silica gel that North Star Industrial provides can be utilized in a wide range of static and dynamic solutions, including compressed air dryers, packaging desiccant, catalyst support, fluid cracking catalysts, and other static and dynamic solutions.
Industrial desiccants and adsorbents are sold in bulk, ranging from 55lb (25kg) bags to a full container load.
There are three basic varieties of silica gels: A, B, and C. Type-A is available in both indicating and non-indicating forms, and it is a narrow pore gel with pore apertures of 28 angstroms.
Gels that indicate can include:
Blue transitioning to pink when saturated.
Yellow transitioning to dark green when saturated.
Yellow transitions to clear when saturated.
Blue Silica Gel
- If visual management of moisture is necessary, blue silica gel is appropriate as a primary desiccant or when combined with other desiccants in various applications. When dried, blue silica gel beads have a rich blue color because they were saturated with a moisture-detecting solution. As it absorbs moisture, the color transitions from blue to purple to pink.
- Blue silica gel, sometimes referred to as a narrow pore silica gel, contains an extensive network of interconnected pores with widths between 20 and 30A. Physical adsorption and capillary condensation are used by these pores to capture and retain the moisture due to their high affinity for it. The optimal conditions for using silica gel are at room temperature (70–90° F) and high relative humidity (60–90% Rh), although it can remove moisture at temperatures as high as 220° F.
- Frequently, silica gel is used with:
- gas drying, compressed air drying,
- air fresheners and packaged items.
Silica Alumina Gel
- Alumina gel is a fine-pored, smooth, water-resistant silica gel that is formed into alumina beads. This product line has low dust content and excellent crush strengths.
- By adjusting the amounts of alumina that are added to fine-pored silica gel, silica alumina gel is produced. The amount of aluminum oxide affects the performance of adsorption. In applications involving liquid water or high free water content, silica alumina gel can be employed independently and still obtain low dew points.
Yellow Silica Gel
- Indicated by the color yellow, silica gel is a pure form of silicon dioxide that has undergone synthetic modification to become a firm, smooth bead. When dried, the beads have a yellow (orange) tint since they were soaked in a moisture-detecting solution. It features a large network of interconnected holes with sizes of 20–30 and is also known as a narrow pore silica gel. Physical adsorption and capillary condensation work together to capture and hold the moisture that these pores have a strong affinity for. When employed at room temperature (70–90 °F) and high relative humidity (60–90 %), silica gel may effectively remove moisture even at temperatures as high as 220 °F.
- When the moisture level reaches 6% by weight, the color usually starts to change, and when it reaches 14% by weight, it is fully changed. Bright green or clear color denotes moisture saturation and signals that the desiccant has to be changed or renewed.
- In any application where visual control of moisture is necessary, such as compressed air dryers, gas drying, breathers, for protection of non-consumable packaged products, drying, and storage of flowers and seeds, etc., as the primary desiccant or combined with other desiccants. The presence of the moisture indication means that yellow signaling silica gel should not be utilized in contact with goods meant for human consumption, such as food or medicines.