Surface treating apparatus and method

Abstract

A back-up apparatus for use with a surface treating apparatus can include a back-up plate having a pad attachment face and a back-up pad having a first pad face and a second pad face. The back-up apparatus can also include a porous interface layer. The interface layer can include an outer face. The back-up apparatus can also include a layer of a first adhesive on the outer face and extending into the interface layer, and a layer of a second adhesive provided on the layer of the first adhesive. The second adhesive can be selected to releasably adhesively bond to an abrasive sheet. The first and second adhesives can be selected such that the adhesive bond between the first adhesive and the second adhesive is stronger than the adhesive bond between the second adhesive and the abrasive sheet.

1 . A back-up apparatus for use with a surface treating apparatus, the back-up apparatus comprising:
 a) a back-up plate having a pad attachment face;   b) a back-up pad, the back-up pad having a first pad face, secured to the pad attachment face, and an opposed second pad face;   c) an porous interface layer, the interface layer comprising an inner face, secured to the second pad face, and an outer face;   d) a layer of a first adhesive provided on the outer face and extending into the interface layer; and   e) a layer of a second adhesive provided on the layer of the first adhesive wherein the second adhesive is selected to releasably adhesively bond to an abrasive sheet, and wherein the first and second adhesives are selected such that the adhesive bond between the first adhesive and the second adhesive is stronger than the adhesive bond between the second adhesive and the abrasive sheet whereby the layer of second adhesive remains bonded to the layer of first adhesive when the abrasive sheet is separated from the back-up apparatus.   
     
     
         2 . The back-up apparatus of  claim 1 , wherein the back-up pad is resiliently flexible and the interface layer is flexible whereby the back-up pad flexes to follow the contours of a surface being sanded. 
     
     
         3 . The back-up apparatus of  claim 1 , wherein the interface layer is a pile material and the outer face comprises a plurality of engagement fibres extending away from the interface layer. 
     
     
         4 . The back-up apparatus of  claim 1 , wherein the first adhesive is mechanically worked into the interface layer and extends below the outer face to provide a three dimensional adhesive layer. 
     
     
         5 . The back-up apparatus of  claim 1 , wherein the interface layer covers substantially all of the outer face. 
     
     
         6 . The back-up apparatus of  claim 1 , wherein the surface area of the interface layer is greater than the surface area of the pad mounting face of the back-up plate. 
     
     
         7 . The back-up apparatus of  claim 1 , wherein the back-up pad is a natural or synthetic rubber. 
     
     
         8 . The back-up apparatus of  claim 1 , wherein the bond between the second adhesive and the abrasive sheet has a first bond strength at 25° C. and a second bond strength at 400° C., the second bond strength being at least 80% of the first bond strength. 
     
     
         9 . The back-up apparatus of  claim 1 , wherein the back-up plate comprises a plurality of plate suction apertures fluidly connectable to a suction housing, the back-up pad comprises a plurality of pad suction apertures in fluid communication with the plurality of plate suction apertures and the interface layer comprises a plurality of interface suction apertures in registration with the pad suction apertures. 
     
     
         10 . The back-up apparatus of  claim 1 , wherein the back-up plate comprises a plurality of plate suction apertures fluidly connectable to a suction housing, the back-up pad comprises an open pad suction channel in fluid communication with the plurality of plate suction apertures and opening to the second pad face and the interface layer comprises an interface suction opening registered with the pad suction channel. 
     
     
         11 . A method of replacing an abrasive sheet on a back-up apparatus, the method comprising:
 f) providing a back-up apparatus comprising:
 i) a back-up plate having a pad attachment face; 
 ii) a back-up pad, the back-up pad having a first pad face secured to the pad attachment face, and an opposed second pad face; 
 iii) a porous interface layer, the interface layer having an inner face secured to the second pad face, and an opposed outer face; 
 iv) a layer of a first adhesive covering the outer face and coating a plurality of discrete fibres extending away from the abrasive mounting face; and 
 v) a layer of a second adhesive provided on the first adhesive and releasably adhesively bonded to the abrasive sheet; 
   g) separating the abrasive sheet from the interface layer;   h) providing a replacement abrasive sheet comprising a first side covered with abrasive material and an opposed second side configured to releasably engage the layer of second adhesive;   i) aligning the second side of the replacement abrasive sheet with the abrasive mounting face of the interface layer; and   j) pressing the second side of the replacement abrasive sheet against the layer of second adhesive on the interface layer.   
     
     
         12 . The method of  claim 11 , wherein the abrasive sheet comprises a base layer, the base layer comprising the first side covered with abrasive material, and comprising an opposed rear face, and a film layer bonded to the opposed rear face of the base layer, and the film layer comprising the opposed second side configured to releasably engage the layer of second adhesive. 
     
     
         13 . The method of  claim 11 , wherein step b) is completed in the absence of transferring the second adhesive from the abrasive mounting face to the abrasive sheet. 
     
     
         14 . The method of  claim 11 , further comprising sealing the peripheral edges of the film layer to the abrasive mounting face whereby debris is inhibited from being deposited between the abrasive mounting sheet and the film layer. 
     
     
         15 . The method of  claim 11 , wherein the film layer is mylar. 
     
     
         16 . The method of  claim 11 , wherein the back-up pad is resiliently flexible and the interface layer is also flexible whereby the interface layer flexes with the back-up pad. 
     
     
         17 - 96 . (canceled)