Felt to always maintain a porous, soft and uniform, after a period of time will be glued to the top of the resin, clay oil and other metals caused by the blockage of the pores, 1 cleaning of clay and pigments such as polyphosphate. 2 dissolved aluminum complex with hydrochloric acid, sulfuric acid, etc.. 3.1000L water temperature in the 40 - 50 degree plus 2KG non-ionic surface active solvent and sodium tripolyphosphate 4KG washing 100KG felt each wash 10 20Min to rinse with water can be felt on the resin cleaning. 4 special solvent formulation for felt