SILICA GEL

SILICA GEL: "Sorb-It� packaged silica gel is made from amorphous silicate. It is a hard, translucent material with an extremely high capacity for moisture at temperatures below 75� F. and at humidity levels above 40%.

Sorb-It� is designed to control moisture levels within packaged products. The function of Sorb-It� when controlling moisture is like a tiny sponge with millions of microscopic pores. Under very low humidity conditions, a small amount of water vapor will be adsorbed in the smallest pores. As humidity increases, the larger pores will begin to fill. For example, at 20% R.H. and 75� F., Sorb-It� can adsorb about 12% its weight in water. At 80% R.H. and 75� F, it can adsorb 35% its weight in water (see Exhibit 1). Unlike a sponge, however, Sorb-It� remains dry even at maximum capacity.

In addition to adsorbing more at higher humidity levels, Sorb-It� will also adsorb more as the time period increases. For example, at 70% R.H. and 75�F, Sorb-It� can adsorb 15% its weight in water within two hours and reach adsorption capacity within eight hours "