Anti-squeal shim
Anti-squeal shim ( 100 ) comprising a fiber reinforced vibration insulating layer ( 110 ) and a vibration absorbing layer ( 120 ), the fiber reinforced vibration insulating layer comprises reinforcement fibers, a filler material and a binder material. There is also provided a method of producing anti-squeal shims, and a method of preventing squeal noise from a disc brake.
1. Anti-squeal shim comprising at least one fibre reinforced predominantly vibration insulating layer and at least one predominantly vibration absorbing layer, wherein the at least one fibre reinforced predominantly vibration insulating layer comprises reinforcement fibres, a filler material and a binder material, wherein the at least one fibre reinforced predominantly vibration insulating layer(s) is thicker than 110 μm and thinner than 200 μm, and the fibre content by weight in the fibre reinforced predominantly vibration insulating layer is 80% or less.
2. Anti-squeal shim according to claim 1 wherein the at least one predominantly vibration absorbing layer is a visco-elastic layer.
3. Anti-squeal shim according to claim 2 wherein the visco-elastic layer is an acrylic or silicone based adhesive layer.
4. Anti-squeal shim according to claim 1 wherein the shim has a pad side and an outer side wherein the at least one fibre reinforced predominantly vibration insulating layer is arranged at the outer side, and the at least one predominantly vibration absorbing layer at the pad side.
5. Anti-squeal shim according to claim 1 wherein the reinforcement fibres comprises at least one of organic fibers, aromatic polyamide fibres, polyamide fibres other than aromatic polyamide fibres, polyolefine fibres, polyester fibres, polyacrylonitrile fibres, polyvinyl alcohol fibres, polyvinylchloride fibres, polyurea fibres, polyurethane fibres, polyfluorocarbon fibres, phenol fibres, cellulose fibres, inorganic fibres, glass fibre, ceramic fibre, rock wool, mineral wool, fused quartz fibre, chemical processed high silica fibre, fused alumina silicate fibre, alumina continuous fibre, stabilized zirconia fibre, boron nitride fibre, alkali titanate fibre, whiskers, or boron fibre.
6. Anti-squeal shim according to claim 1 wherein the at least one predominantly vibration absorbing layer is a layer of a viscous media arranged in between two plates of rigid material.
7. Anti-squeal shim according claim 1 , further comprising one or more metal plates.
8. Anti-squeal shim according claim 1 wherein the fibre content by weight in the fibre reinforced predominantly vibration insulating layer is 50% or less.
9. Anti-squeal shim according claim 1 wherein the fibre content by weight in the fibre reinforced predominantly vibration insulating layer is 30% or less.
10. Anti-squeal shim according claim 1 wherein the fibre content by weight in the fibre reinforced predominantly vibration insulating layer is 23% or less.