Activated Bentonite (Activate Clay)
Activated clay or bentonite is an absolutely natural desiccant widely used for the protection of industrial packaging. The dehydrating clay is presented in slightly coarser granules than silica gel and is inserted in the same sachets of standard material.
Thanks to its dehydrating qualities and excellent value for money, clay is a valid alternative to silica gel in all general packaging applications.
Bentonite sachets can emit a very fine brown-gray powder, which is also potentially abrasive, it is not recommended for use with delicate optical devices such as cameras, video cameras, binoculars, microscopes or delicate materials.
Clay is an economic alternative to the more common silica gel. Even if the name "activated clay" can suggest a treatment with chemical additives, the clay (or bentonite) does not come into contact with any substance during the processing phase.
The bentonite is extracted in the quarry and subsequently ground to crush it in granules. Subsequently the granules are dried in ovens to remove all traces of moisture. The product thus processed is ready to be packaged in the various desiccant bags in various weights.
Bentonite has an absorption capacity almost identical to silica gel (the differences are practically minimal) but since it is a natural product and not chemically altered, the capacity to absorb humidity varies from one batch to another.
For this reason the bentonite sachets are identified not with the weight but with the absorption capacity, identified in dehydrating units (U) in accordance with the NFH technical standards. According to these regulations, the dehydrating unit is the quantity of clay necessary to absorb 6 grams of water vapor under standard conditions (40% relative humidity with a temperature of 23° C).
Exemplifying this concept in simple terms and making a comparison with the more well-known silica gel, it can be said that sachets of 60 grams of silica gel coming from different batches have the same moisture absorption capacity. This is because silica gel is still a synthetic product, specially created to achieve a constant standard of dehydrating capacity. The same thing is not valid for sachets that use clay as a dehydrating material. In order to reach the dehydrating standard dictated by the NFH, DIN or MIL directives, the amount of dehydrating material in the sachet is changed (almost always in excess). Hence the dehydrating capacity of 60 grams of silica gel, obtained on average with 70 grams of clay (bentonite), the dehydrating capacity of 240 grams of silica gel are obtained with 260-270 grams of clay (bentonite) and so on.
Thus the slightly lower dehydrating capacity of the clay compared to the silica gel is increased, increasing its quantity. At the same weight or excess, however, the clay stands at very sensitive levels of economy compared to silica gel.
Just like silica gel sachets, bentonite can also be regenerated using only microwave ovens since other systems are either completely uneconomical (electric oven) or absolutely useless (radiator, sun exposure, etc.).
Since bentonite is a 100% natural material it can be disposed of simply by dispersing it in the environment, naturally after having extracted it from the container casing which must be thrown apart in the common garbage.
Bentonite can be spread in the garden or simply by using it as a pet litter.