Desiccant-coated substrate and method of manufacture

A process for making a device for gas treatment comprising a desiccant-coated substrate capable of being used at temperatures over 150 degrees Fahrenheit, the device having passageways for gas to flow through and contact the desiccant, the desiccant being in the form of particles and the particles having pores and being adhered to the substrate by a binder, the coated substrate being sufficiently flexible and the coating having sufficient adherence to the substrate so that the coated substrate can be formed into corrugated shapes, the desiccant particles in the coated substrate having at least 60% of their original adsorption capacity and the binder having good breathability;

• said process comprising the steps:
• (a) forming an aqueous suspension comprising particles of one or more desiccants, a water-based organic binder, a suspending agent to help maintain the desiccant particles in suspension, and an organic pore-clearing agent at least some of which enters at least some of the pores of the desiccant particles;
• (b) depositing the suspension on the substrate;
• (c) causing the binder of the deposited suspension to set so that the deposited desiccant particles adhere to the substrate and causing at least some of the pore-clearing agent to leave the pores of the desiccant particles to prevent the binder from occluding at least some of the pores of the adhered desiccant particles, thereby to form a desiccant-coated substrate of sufficient flexibility and a coating having sufficient adherence to the substrate so that the desiccant-coated substrate can be formed into corrugated shapes and in which the desiccant particles in the coated substrate have at least 60% of their original adsorption capacity and the binder has good breathability;
• and
• (d) forming the desiccant-coated substrate into shapes having passageways for the flow of gas arranged so that gas flowing through the passageways comes into contact with the desiccant.