Method and installation for producing a multi-layered wet friction material

Abstract

A method for producing a multi-layered wet friction material includes providing a bottom layer, providing a top layer produced independently of the bottom layer from different materials, and bonding the bottom layer to the top layer. The bottom layer and the top layer may be produced from different formulations and supplied as raw papers. A formulation of the top layer may include twenty to sixty percent (20%-60%) filler, ten to forty percent (10%-40%) wood pulp, five to ten percent (5%-10%) aramid, and twenty-five to thirty-five percent (25%-35%) phenolic resin. A formulation of the bottom layer may include ten to fifty percent (10%-50%) filler, ten to forty percent (10%-40%) wood pulp, five to ten percent (5%-10%) aramid, five to fifteen percent (5%-15%) carbon, and twenty-five to thirty-five percent (25%-35%) phenolic resin.

Claims

1. A method for producing a multi-layered wet friction material, comprising: providing a bottom layer supplied as a first raw paper; providing a top layer produced independently of the bottom layer from different materials and a different formulation, the top layer supplied as a second raw paper; bonding the bottom layer to the top layer by means of temperature and pressure; and winding the multi-layered wet friction material on a suitable roll.

2. The method of claim 1, wherein: a formulation of the top layer comprises: twenty to sixty percent (20%-60%) filler; ten to forty percent (10%-40%) wood pulp; five to ten percent (5%-10%) aramid; and twenty-five to thirty-five percent (25%-35%) phenolic resin; and a formulation of the bottom layer comprises: ten to fifty percent (10%-50%) filler; ten to forty percent (10%-40%) wood pulp; five to ten percent (5%-10%) aramid; five to fifteen percent (5%-15%) carbon; and twenty-five to thirty-five percent (25%-35%) phenolic resin.

3. The method of claim 1, wherein: the bottom layer comprises a basis weight of one hundred to two hundred grams per square meter (100-200 g/m^2); and the top layer comprises a basis weight of two hundred to four hundred grams per square meter (200-400 g/m^2).

4. The method of claim 1, further comprising coating the bottom layer with a binder material prior to the step of bonding the bottom layer to the top layer.

5. The method of claim 4, wherein the binder material is a resin powder.

6. The method of claim 1, wherein the bonding the bottom layer to the top layer comprises coating the bottom layer with a binder material and connecting the bottom layer to the top layer by a lamination process.

7. The method of claim 1, wherein the bonding the bottom layer to the top layer comprises coating the bottom layer with a binder material and connecting the bottom layer to the top layer in a double-belt press.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantages, features and details of the disclosure emerge from the following description, in which various exemplary embodiments are described in detail with reference to the drawings. In the figures:

(2) FIG. 1 shows a top layer in section;

(3) FIG. 2 shows a bottom layer in section;

(4) FIG. 3 shows a schematic representation of a method step in the production of a wet friction material;

(5) FIG. 4 shows a schematic representation of a further method step in the production of a wet friction material;

(6) FIG. 5 shows the wet friction material in section; and

(7) FIG. 6 shows an installation for producing the wet friction material.

DETAILED DESCRIPTION

(8) In FIG. 1, an upper layer 1 for producing a wet friction material, denoted by 14 in FIG. 5, is shown in a simplified section. In FIG. 2, a bottom layer 2 for producing the wet friction material designated by 14 in FIG. 5 is shown in a simplified section. The top layer 1 and the bottom layer 2 are produced independently of one another using a conventional paper making process, which is also referred to in short as the paper process.

(9) In FIG. 3, it is shown schematically that during the production of the wet friction material 14, the bottom layer 2 is first supplied to a conveyor belt 3. The conveyor belt 3 is driven with the aid of two transport rollers 4, 5.

(10) A binder material 8 in the form of a binder material layer 9 is applied to the substrate 2 with the aid of two binder rollers 6, 7. The top layer 1 is then applied to the binder material layer 9. This results in a semi-finished product 10 in which the binder material layer 9 has not yet hardened.

(11) The binder material is an adhesive that includes, for example, a resin, e.g., a phenolic resin. The adhesive, e.g., the resin, hardens under the action of heat, so that the bottom layer 2 is firmly bonded to the top layer 1 via the binder material layer 9.

(12) FIG. 4 indicates schematically that the semi-finished product 10 from FIG. 3 is passed between two calender rolls 11, 12 to bond the top layer 1 to the bottom layer 2 with the aid of the binder material layer 9. The calender rolls 11, 12 may be heated to supply the binder material layer 9 with the heat required for curing. This results in an intermediate product 13.

(13) In FIG. 5, the wet friction material 14 is shown schematically in section. The top layer 1 is firmly bonded to the bottom layer 2 with the aid of the binder material layer 9. The bottom layer 1 and the top layer 2 are made of different materials.

(14) The materials produced separately from one another are connected to one another in an additional process, for example in the lamination or laminating process indicated in FIG. 4, to form the multi-layered material shown in FIG. 5. This process is characterized by the fact that the different materials are connected to one another by means of pressure and temperature in a continuous or discontinuous process.

(15) An installation 20 for producing the wet friction material 14 is shown schematically in FIG. 6. The installation 20 includes two coils 21, 22, via which different raw papers 23, 24 are supplied.

(16) The term coil denotes a spool, roll, or cylinder on which the different raw papers 23, 24 are wound. The raw paper 23 is used to represent the bottom layer 2 of the wet friction material 14. The raw paper 24 is used to represent the top layer 1 of the wet friction material 14.

(17) The installation 20 includes a scatter powder coating device 27. The scatter powder coating device 27 includes a powder spreader 28, via which a resin powder 29 is applied to the substrate 2. The resin powder 29 is used to represent the binder material layer 8 on the substrate 2.

(18) The installation 20 also includes a double-belt press 33 with two belts 31, 32, which are driven by drive rollers, which are not designated in any further detail. The bottom layer 2 with the binder material 8 is first supplied to the belt 31 arranged at the bottom in FIG. 6. Then the raw paper 24 is supplied to represent the top layer 1. The binder material 8 on the bottom layer 2 can be heated via an optional heating device 30 before the raw paper 24 is supplied.

(19) After the raw paper 24 has been supplied, the two raw papers 23 and 24 together with the binder material 8 are passed between the belts 31, 32 of the double-wall press 33.

(20) The double-belt press 33 is equipped with heating devices 36, 37 and cooling devices 34, 35 at the top and bottom in FIG. 6. The heating device 36 is arranged at the bottom in FIG. 6, i.e., below the bottom layer 2. The cooling device 35 is also arranged below in FIG. 6, i.e., below the bottom layer 2. The cooling device 37 is arranged at the top in FIG. 6, i.e., above the top layer 1. The cooling device 34 is also arranged above the top layer 1 in FIG. 6.

(21) With the heating devices 36, 37 heat is supplied to the raw papers 23, 24 and the binder material 8 arranged therebetween. The heat supplied has the result that resin components, e.g., phenolic resin components, harden in the bottom layer 2, the top layer 1, and in the binder material 8, so that a stable bond results, which is the wet friction material 14. The cured wet friction material 14 is cooled with the cooling devices 34, 35. The cooled wet running friction material 14 is then wound onto a roll 38.

REFERENCE NUMERALS

(22) 1 Top layer 2 Bottom layer 3 Transport belt 4 Transport roller 5 Transport roller 6 Binder roller 7 Binder roller 8 Binder material 9 Binder material layer 10 Semi-finished product 11 Calender roll 12 Calender roll 13 Intermediate 14 Wet friction material 20 Installation 21 Coil 22 Coil 23 Raw paper 24 Raw paper 27 Scatter powder coating device 28 Powder spreader 29 Resin powder 30 Optional heating device 31 Belt 32 Belt 33 Double-belt press 34 Cooling device 35 Cooling device 36 Heating device 37 Heating device 38 Roller