Roughing Disc Having a Backing Layer

Abstract

A roughing disc for machining material surfaces, which may have a disc-shaped main body having a tool side, which can face a tool, and a workpiece side, which can face a workpiece, the main body having a central opening through which an axis of rotation passes and which serves for direct or indirect attachment of a drive shaft of the tool, a disc-shaped backing layer disposed on the tool side, at least one abrasive layer, and a separating layer between adjacent layers. The backing layer may be made of a material mixture that is free of abrasive additives and that has at least one mineral additive.

1 . A roughing disc for machining material surfaces, comprising: a disc-shaped main body having a tool side, which can face a tool, and a workpiece side, which can face a workpiece, the main body comprising a central opening through which an axis of rotation passes and which serves for direct or indirect attachment of a drive shaft of the tool, a disc-shaped backing layer disposed on the tool side, at least one abrasive layer, and a separating layer between adjacent layers, wherein the backing layer is made of a material mixture that is free of abrasive additives and that comprises at least one mineral additive. 
     
     
         2 . The roughing disc according to  claim 1 , wherein the mineral additive is selected from the group consisting of basalt, quartz sand, wollastonite, aluminum silicate, kaolin, and combinations thereof. 
     
     
         3 . The roughing disc according to  claim 1 , wherein the mineral additive has a Mohs hardness of preferably between 7 and 9. 
     
     
         4 . The roughing disc according to  claim 1 , wherein the mineral additive has a grain size of 200 to 500 μm. 
     
     
         5 . The roughing disc according to  claim 1 , wherein the grain of the mineral additive is covered in phenolic resin systems comprising a resol/novolak mixture. 
     
     
         6 . The roughing disc according to  claim 5 , wherein the resol has a viscosity of 1200 to 3500 mPa·s. 
     
     
         7 . The roughing disc according to  claim 5 , wherein the novolak has a hexamethylenetetramine content of 12 to 16 vol %, and a flow length of 17 to 26 mm. 
     
     
         8 . The roughing disc according to  claim 5 , wherein defined amounts of other additives and/or aggregates of less than 20 vol % are additionally added to the novolak. 
     
     
         9 . The roughing disc according to  claim 1 , wherein the separating layer is a glass fabric layer.