Support bodies and method for improving wear and tear on support bodies in large scale grinders

Abstract

The invention relates to a method for improving wear and tear on support bodies (54) for plates or grinding belts in large-scale grinders (1). The support body (54) has a base body (18), onto which an abrasion-resistant primary layer of at least 0.3 mm thickness is applied using a thermal spraying process. This is configured as an inhomogeneous layer with an oxide entrapment of a specific porosity. If the support body (54) is a roll for the forward feed unit (20, 28), the roll body is roughened and a primer and the primary layer are applied using a thermal spraying process. Approximately 50 % of the primary layer consists of chromium steel, in particular 13 % chromium steel and an abrasion-resistant hard material and said primary layer provides a coarse surface with good grip that is resistant to wear and tear. If the support body (54) is a grinding-belt contact roll (9, 9'), the latter is polished after the thermal spraying process. If the support body (54) is a grinding belt shoe (50), the base body (18) is roughened and an adhesive layer and then the primary layer are applied in a thermal spraying process. The wear-resistant primary layer is polished to create a smooth surface and the layer construction is configured to produce a high degree of slip.

1 . Method for improving wear performance of support bodies in wide-belt sanding machines ( 1 ) at least as regards the drive rollers ( 23 ) of the in-feed unit ( 20 ) and/or the backing roller ( 32 ) 
 characterized in that    the support body has a base body onto which    a) a primer ( 72 ) and then    b) a primary coating ( 73 ) are applied using a thermal spray process    and onto which said base body ( 18 ,  51 ) a coating structure consisting of a 0.1 to 0.3 mm primer ( 72 ) on top of which an abrasion-resistant primary coating ( 73 ) of at least 0.3 mm is applied by using a thermal spray process, and said primary coating ( 73 ) is designed as an inhomogeneous coating with oxide inclusions, and approximately 50% of the primary coating ( 73 ) consists of chromium steel, in particular 13% chromium steel, and an abrasion-resistant hard material and said primary coating ( 73 ) results in a rough surface that has a good grip and is resistant to wear.    
     
     
         2 . Method for improving wear performance of support bodies in wide-belt sanding machines ( 1 ) at least as regards the abrasive-belt contact rollers ( 9 ,  9 ′) 
 characterized in that  
 the support body has a base body onto which  
 a) a primer ( 72 ) and then  
 b) a primary coating ( 83 ) [sic] are applied using a thermal spray process  
 and onto which said base body ( 18 ,  51 ) a coating structure consisting of a 0.1 to 0.3 mm primer on top of which an abrasion-resistant primary coating ( 73 ) of at least 0.3 mm is applied by using a thermal spray process, and said primary coating ( 73 ) is designed as an inhomogeneous coating with oxide inclusions, and in a preferred embodiment the primary coating ( 73 ) consists of 13% chromium steel, and the surface of said base body after the thermal application of the primary coating ( 73 ) is sanded to obtain a smooth surface.  
 
     
     
         3 . Method for improving wear performance of support bodies in wide-belt sanding machines ( 1 ) at least as regards the opposing shoe ( 50 ) 
 characterized in that    the support body has a base body onto which    a) a primer ( 72 ) and then    b) a primary coating ( 73 ) are applied using a thermal spray process    and onto which said base body ( 18 ,  51 ) a coating structure consisting of a 0.1 to 0.3 mm primer on top of which an abrasion-resistant primary coating ( 73 ) of at least 0.3 mm is applied by using a thermal spray process, and said primary coating ( 73 ) is designed as an inhomogeneous coating with oxide inclusions, and said primary coating is wear resistant and the coating structure is designed to have a high degree of slip.    
     
     
         4 . Method according to  claims 1  to  3  
 characterized in that  
 the primary coating ( 73 ) is applied using an arc spray process and in a preferred embodiment has a certain degree of porosity.  
 
     
     
         5 . Method according to  claim 1  to  4  
 characterized in that  
 the surface of the base body ( 18 ,  51 ) is roughened prior to the thermal application particularly through sandblasting.  
 
     
     
         6 . Method according to  claims 1  to  5  
 characterized in that  
 the base body ( 18 ,  51 ) is an oxidizable metal body and the thermal spray application must be done in a narrow time window notably in under three hours after the surface has been roughened.  
 
     
     
         7 . Method according to  claims 1  to  6  
 characterized in that  
 after the base body ( 18 ,  51 ) is roughened, a primer ( 72 ) in particular one of aluminum bronze or zinc substrate is applied using a thermal spray process prior to the application of the primary coating ( 73 ) using a thermal arc spray process.  
 
     
     
         8 . Support bodies for platens or abrasive belts ( 6 ,  7 ) in wide-belt sanding machines ( 1 ) where at least one of the drive rollers ( 9 ) of the in-feed unit has a base body ( 18 ) made of plastic or metal ( 73 ) [sic]
 characterized in that    the support body has a base body ( 18 ,  51 ) that has a coating structure consisting of approximately 0.1 to 0.3 mm primer ( 72 ) and an outer, abrasion-resistant primary coating ( 73 ) of at least 0.3 mm applied by using a thermal spray process, and said primary coating ( 73 ) is designed as an inhomogeneous coating with oxide inclusions, and approximately 50% of said primary coating ( 73 ) consists of a chromium steel alloy, and an abrasion-resistant hard material and said primary coating ( 73 ) results in a rough surface that has a good grip and is resistant to wear.    
     
     
         9 . Support bodies for platens or abrasive belts ( 6 ,  7 ) in wide-belt sanding machines ( 1 ) where the abrasive-belt contact rollers ( 8 ,  9 ) and/or the opposing shoe ( 50 ) and/or the backing roller ( 32 ) have a base body ( 51 ) made of plastic or metal 
 characterized in that    the support body has a base body ( 18 ,  51 ) that has a coating structure consisting of approximately 0.1 to 0.3 mm primer ( 72 ) and an outer, abrasion-resistant primary coating ( 73 ) of at least 0.3 mm applied by using a thermal spray process, and said primary coating ( 73 ) is designed as an inhomogeneous coating with oxide inclusions, and in a preferred embodiment consists of chromium steel and is sanded to obtain a smooth surface.    
     
     
         10 . Support body according to  claim 8  or  9  
 characterized in that  
 the primary coating ( 73 ) is inhomogeneous and has a porous structure.  
 
     
     
         11 . Support body according to  claims 8  to  10  
 characterized in that  
 the primer ( 72 ) has a thickness of approximately 0.1 to 0.2 mm and the primary coating ( 73 ) is applied at a thickness of 0.4 to 5 mm, and in the case of abrasive-belt contact roller ( 8 ,  9 ) and/or opposing sanding shoe ( 50 ), and/or backing roller ( 32 ), the coating thickness is at least 0.3 to 4 mm.