Impregnating agent application methods

Materials and Methods of Application. All paper substrates for the impregnating agent/paper system studies were a buffered wood sulfite, Gracie Sons Acid-Free Lining Paper, Lot 3 (supplied by Charles R. Gracie Sons, Inc., New York, N.Y. 10022). Samples were all cut in... 

Application methods for the impregnating agent The durability of the water-repellent effect depends not only on the product quality but also on the depth of penetration achieved. In order to ensure sufficient penetration, the impregnating solution should be applied by spraying or flooding. Airless spraying techniques can also be used provided the seals and hoses are solvent-resistant. 

The coating methods presented earlier are all used to create films of materials upon surfaces. There is another class of coatings from C02 that has not yet been discussed. Using both liquid and supercritical C02, it is possible to coat or impregnate porous and woven materials with a desired polymer or chemical agent. Three specific applications will be discussed in turn. 

For applications where high surface area is not important, the ceramic foam may be loaded ndi catalytic agents through single or multiple impregnation of suitable salts, followed Iw heat-treatment at moderate temperatures. Alternatively, a washcoat may be added with the same procedures used for monolithic substrates [20]. Surface areas increase from less than 1 mV to above 30 mV depending on the amount of washcoat added. In Ais way, washcoated foams have been loaded with metals and oxides [18,19], zeolites [20] and carbon [21]. Other methods, e.g. chemical vapor deposition, have also been su ested [23,24]. 

---