PROSorb is a new silica gel ideally suited to stabilize relative humidity inside museum display cases and storage cabinets.
The ideal level of humidity for most museum display cases and storage cabinets is a level between 40 - 60 % RH (Relative Humidity). It is desirable to maintain an appropriate RH level for as long as possible. PROSorb has a unique and exceptional adsorption capacity within the 40 - 60 % RH range and surpasses all other products sold for this purpose. PROSorb is able to maintain a stable RH within narrow margins through its ability to both absorb and desorb water vapour; and is shipped pre-conditioned to your desired humidity level. PROSorb also has a longer life span than other silica gels.
Free of Chlorides: PROSorb contains no lithium chloride, as some other products do (Lithium chloride is a chemical salt, potentially harmful to many metals. This salt can be transferred to metals in dust or by human touch). PROSorb consists of 97% SiO2 and 3% Al2O3.
Low Abrasion: PROSorb beads produce less dust than other silica gels (abrasion < 0,05 weight-% according to MIL-D).
High Bulk Density: One kg of PROSorb only needs a volume of ca. 1,5 l (much less than some other silica gels).
Long Term Stability: PROSorb maintains the greater part of its capacity well beyond the 2-5 years when other silica gels have lost a large portion of their capacity.
Economical: PROSorb is a better value than the other products sold for the same purpose.
Temperature Dependent: PROSorb is conditioned in relation to temperature, and reacts in the same way organic materials do. Therefore there will be no, or little, transfer of water vapour between organic materials and PROSorb if the temperature changes. Under fluctuating temperatures this property protects wooden objects and other organic materials from swelling or shrinking. Note that the conditioning indicated on the labels refers to 20°C. At 10°C the conditioning of the cassettes will be around 1 - 1,5 % RH lower, at 30°C around 1 - 1,5 % RH higher.
PROSorb Beads and Cassettes:
PROSorb is available in 500 (half-size) or 950 grams (full size) cassettes. Cassettes are open to the air on one side only, and are designed to be laid flat for use. They easier to handle than beads: they don't need trays or containers and may be easily exchanged. Re-conditioning the RH-value of a cassette can be done easily by weight. Cassettes are constructed of sturdy polypropylene and vapour permeable non-woven polyester fabric. They are filled with PROSorb beads.
Full-size and half-size cassettes are available:
Full-size Cassettes: dimensions: L 335 mm / 13.2 ", W 110 mm / 4.3", H 44 mm / 1.75 ". Content: beads. One or more cassettes per cubic metre of air volume / 30 cubic feet are required depending on circumstances of application, especially case leakage.
Half-size cassettes: dimensions: L 335 mm / 13.2 ", W 110 mm / 4.3", H 24 mm / 1". Content: beads. One half-size cassette will be sufficient for 0,7 m3 / 20 cubic feet, depending on circumstances of application.
Bulk density: 0.7 kg/l
Pore volume: 0.5 ml/g
Breaking strength: > 200 N
Internal surface area: 750 m2 /g