Because they are in direct contact with the product, these desiccant packages must be clean as well as effective. The material must be porous, but not so porous that dust can go through the material. Desiccants have been designed with pharmaceuticals in mind. Silica gel, one of the preferred desiccants, is unlikely to create dusting problems, says Stasen. In addition, the materials used for sachets keep any dust from contaminating the product.
Canisters have micropores, tiny holes that contain the desiccant and prevent leaks.
And the newest desiccant products are designed to be clean as well as effective. DuPont has created a new Tyvek suitable for packaging desiccants. Tyvek 1025BL is a thinner, lighter-weight style designed for less stringent applications where less strength is required. The 1025BL has higher permeability and greater moisture vapor transmission, enabling the desiccant to act more quickly if manufacturers have that requirement. We are anticipating that we'll see more manufacturers investigating the possibility of using 1025BL instead of kraft paper for packaging desiccants, because the two are similar in cost.