Aged roofing tile mfr. - by scratching clay extrudate, cutting, coating with clay slurry and granules and firing

摘要

Method for mfg. tiles with an aged appearance is described in which, immediately after leaving the extruder, the extrudate is given a surface scratching then cut into tiles which are then coated with a clay slurry and a granular prod. is sprinkled onto the slurry before firing. The slurry and granular coatings may be repeated before firing. The tiles can be made directly to have the same appearance as tiles which have been on buildings for a century or more, and hence be suitable to replace existing tiles or to reroof old buildings.