Binder-free Friction Linings, Process for Their Production, And Their Use

Abstract

Expanded graphite and/or vermiculite are introduced into the friction lining mixture to eliminate or substantially reduce the amount of binder present therein. The friction lining at most contains from 2.5% by weight of binder. By omitting/reducing binder, the production is very stable and the friction linings can be easily reproduced. The process steps of hardening (including the hardening furnace) and scorching (including the necessary equipment) can be omitted when making such friction linings.

1 . A friction lining for a motor vehicle, comprising:
 a friction lining mixture that contains expanded graphite and/or expanded vermiculite; and   optionally a binder in a maximum amount of 2.5% by weight relative to the friction lining mixture.   
     
     
         2 . The friction lining according to  claim 1 , wherein friction lining mixture is binder-free. 
     
     
         3 . The friction lining according to  claim 1 , wherein the friction lining mixture further comprises from 30% to 65% by weight of steel fibers. 
     
     
         4 . The friction lining according to  claim 1 , wherein the friction lining mixture further comprises from 30% to 65% by weight of metal fibers. 
     
     
         5 . The friction lining according to  claim 1 , wherein the friction lining mixture contains from 5% to 26% by weight of expanded graphite and/or expanded vermiculite. 
     
     
         6 . The friction lining according to  claim 1 , wherein the expanded graphite has a particle size in a range of from 0.25 mm to 1.5 mm. 
     
     
         7 . A method for producing a friction lining, comprising:
 preparing a friction lining mixture of expanded graphite and/or expanded vermiculite, and optionally a binder in a maximum amount of 2.5% by weight relative to the friction lining mixture;   pressing the friction lining mixture into a heated mold.   
     
     
         8 . The method according to  claim 7 , wherein the friction lining mixture further comprises from 30% to 65% by weight of metal fibers. 
     
     
         9 . The method according to  claim 7 , wherein the friction lining mixture further comprises from 30% to 65% by weight of steel fibers. 
     
     
         10 . The method according to  claim 7 , wherein the friction lining mixture contains from 5% to 26% by weight of expanded graphite and/or expanded vermiculite. 
     
     
         11 . The method according to  claim 7 , wherein the expanded graphite has a particle size in a range of from 0.25 mm to 1.5 mm. 
     
     
         12 . The method according to  claim 7 , wherein the friction lining mixture is binder-free. 
     
     
         13 . The method according to  claim 7 , wherein the friction lining removed from the mold is not hardened. 
     
     
         14 . The method according to  claim 6 , wherein the friction lining removed from the mold is not scorched. 
     
     
         15 . The method according to  claim 6 , wherein the mold is heated to a temperature in the range of from 135° C. to 240° C., and wherein the pressing is at a pressure of from 45 Mpa to 200 MPa for a pressing time duration of from 50 seconds to 300 seconds.