OUTER COATING WITH WATER-PERMEABLE PROPERTIES

摘要

The invention relates to water-permeable outer coating consisting of plastic coated quartz fine gravel grains, exhibiting a narrow grain band spacing, to form large interspacing between individual grains. Binding of the eventually dyed individual grains is carried out in a mixing process in which little resin is added for conglutination of individual grains after the coating is applied.