Novel product from Huiyuan: orange silica gel indicator, replacement of blue silica gel.

Color-changing Silica Gel, also called Blue Gel is a kind of high tech and valued indicating adsorbent which is made from highly active adsorbent--Narrow Pore Silica Gel. It is a high end desiccant. Now the State Standard is widely used in China, [Refer to Blue Silica Gel Indicator & Color-changing Silica Gel, HG/T2765.4-1996.] The usual processing method in the world is to combine Narrow Pore Silica Gel (Pore Diameter: 2-3 nm, Surface Area: 600m2/g ) with chloride cobalt (CoCl2). The main feature of Blue Silica Gel is that it has high adsorption capacity of steam in the air, and change its color from blue to purple alone with the water increasingly adsorbed.

The total output of Blue Silica Gel is above 6000MT per year in China, in which about 70%-80% is exported, at a value about 8 million US Dollar, which is over 30% of the amount earned through silica gel export. With people putting more and more attention on environment protection, pollution caused by some chemical products are taken seriously by the people in many countries. Cobalt chloride is considered to be one of the carcinogenic material in the developed nations. China is one of the major exporters of indicating silica gel, so it is a subject of great importance that whether we can develop a new indicating gel product in a short time to maintain the position of major exporter by elimination the pollution of cobalt chloride. The technologists in our company, after half a year's hard work, have already developed a new Blue Gel replacement -- Orange Silica Gel Indicator or Non-cobalt indicating Silica Gel. Compared with the blue gel, in addition to the color change, the new product has markedly higher adsorption capacity with lowered production cost. This is a great breakthrough in the field of silica gel indicator in the world. The tests show that the new product is apparently better than the original blue gel and indicator. Because of the difference in color change and process of moisture absorption, we have set up a new factory standard.

Comparison of specification for the silica gel indicator (enterprise standard) with blue gel indicator (industrial standard)

According to tests on six batches of samples, the adsorption to water vapor is markedly higher than the original blue gel at specified relative humidity, and the color change is apparent after equilibration. Hence the enterprise standard is higher in adsorbence by 1%, 2% and 4%, which makes the orange silica gel indicator even more competitive in the world market.