Method of making mounting mats for mounting a pollution control panel

Patent metadata

Field	Value
Publication number	US-9834875-B2
Application number	US-68219008-A
Country	US
Kind code	B2
Filing date	Oct 7, 2008
Priority date	Oct 9, 2007
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

A method of making mounting mats comprising the steps of: (i) supplying inorganic fibers through an inlet of a forming box having an open bottom positioned over a forming wire to form a mat of fibers on the forming wire, the forming box having rollers for breaking apart clumps of fibers and an endless belt screen; (ii) capturing clumps of fibers on the endless belt; (iii) conveying captured clumps of fibers on the endless belt so as to enable captured clumps to release from the belt and be broken apart by the rollers; (iv) transporting the mat of fibers out of the forming box by the forming wire; and (v) compressing and restraining the mat of fibers to thereby obtain a mounting mat having a desired thickness suitable for mounting a pollution control element in a pollution control device.

First claim

What is claimed is:

1. A method of making intumescent mounting mats for use in a pollution control device comprising the steps of:
(i) supplying inorganic fibers through an inlet of a forming box having an open bottom positioned over a forming wire to form a mat of fibers on the forming wire, the forming box having a plurality of fiber separating rollers provided in at least one row in the housing between the inlet and housing bottom for breaking apart clumps of fibers and an endless belt screen;
(ii) supplying an intumescent material into the forming box so as to be included in and distributed in the mat of fibers, with the amount of supplied intumescent material being enough to produce an intumescent mat of fibers;
(iii) capturing clumps of fibers on a lower run of the endless belt beneath fiber separating rollers and above the forming wire;
(iv) conveying captured clumps of fibers on the endless belt above fiber separating rollers to enable captured clumps to release from the belt and to contact and be broken apart by the rollers;
(v) transporting the intumescent mat of fibers out of the forming box by the forming wire; and
(vi) compressing the intumescent mat of fibers and restraining the intumescent mat of fibers in its compressed state thereby obtaining an intumescent mounting mat having a desired thickness suitable for mounting a pollution control element in the housing of a pollution control device.

2. The method of making intumescent mounting mats according to claim 1 , wherein no organic binder or less than 5% by weight of organic binder is used to produce the intumescent mounting mat.

3. The method of making intumescent mounting mats according to claim 1 , wherein the mat of fibers is subjected to heat treatment before, during and/or after said compression.

4. A method according to claim 3 , wherein the method further includes the step of supplying polymeric fibers or polymeric powder or both into the forming box, and said polymeric fibers or polymeric powder or both are capable of melting or softening at the temperature of heat treatment so as to bond the inorganic fibers and restrain the mounting mat in its compressed state upon cooling.

5. A method according to claim 1 , wherein the step of compression of the mat of fibers includes needling, stitch-bonding, resin bonding, applying pressure and combinations thereof.

6. The method of making intumescent mounting mats according to claim 1 , wherein the compressed mat is impregnated with a dispersion of nanoparticles.

7. The method of making intumescent mounting mats according to claim 1 , wherein the compressed mat is coated on one or both of its opposite major sides with a high friction coating.

8. A method according to claim 1 comprising forming a first mat of fibers by performing steps (i) to (v) of the method, forming at least one second mat of fibers on said first mat by repeating steps (i) to (v) with the first mat being provided on the forming wire and carrying out step (vi) of the method so as to obtain a mounting mat having a first and second mat of fibers.

9. Method according to claim 8 wherein said first mat is compressed by carrying out step (vi) of the method before forming said second mat thereon.

10. The method of making intumescent mounting mats according to claim 1 , wherein the intumescent mat of fibers is impregnated with less than 5% by weight of an organic binder and is subjected to heat treatment during said compression.

11. A method according to claim 10 , wherein the method further includes the step of supplying the organic binder into the forming box, the organic binder includes polymeric fibers or polymeric powder or both, and said polymeric fibers or polymeric powder or both are capable of melting or softening at the temperature of heat treatment so as to bond the inorganic fibers and restrain the mounting mat in its compressed state upon cooling.

12. The method of making mounting mats according to claim 1 , wherein a major side of the compressed mat is coated with a high friction coating.

13. Method of making a pollution control device comprising: making an intumescent mounting mat according to the method of claim 1 and mounting a pollution control element in a metallic housing by disposing said mounting mat between said pollution control element and said metallic housing.

14. A method of reducing the amount of shot in shot-containing inorganic fibers comprising the steps of:
supplying shot-containing inorganic fibers through an inlet of a forming box having an open bottom positioned over a forming wire, the forming box having a plurality of fiber separating rollers provided in at least one row in the housing between the inlet and housing bottom;
feeding the fibers through the plurality fiber separating rollers and generating a mixture of fibers and shot particles,
capturing the mixture of fibers and shot particles and separating the shot particles from the fibers;
capturing the fibers on the forming wire and transporting the fibers out of the forming box by the forming wire.

15. A method of making mounting mats for use in a pollution control device comprising the steps of:
producing inorganic fibers according to the method of claim 14 ;
forming the inorganic fibers into a mat of fibers on the forming wire;
transporting the mat of fibers out of the forming box by the forming wire; and
compressing the mat of fibers and restraining the mat of fibers in its compressed state thereby obtaining a mounting mat having a thickness for mounting a pollution control element in the housing of a catalytic converter.

16. The method of making mounting mats according to claim 15 , wherein no organic binder or less than 5% by weight of organic binder is used to produce the mounting mat.

17. The method of claim 15 wherein essentially no intumescent material is supplied into the forming box.

18. The method of making mounting mats according to claim 15 , wherein the mat of fibers is subjected to heat treatment before, during and/or after said compression.

19. A method according to claim 18 wherein polymeric fibers or polymeric powder are further charged into the forming box and wherein the polymeric fibers or polymeric powder are capable of melting or softening at the temperature of heat treatment.

Assignees

• Kunze Ulrich E
• Lalouch Lahoussaine
• Middendorf Claus
• Krieg Harald H
• 3M Innovative Properties Co

Inventors

• Kunze Ulrich E
• Lalouch Lahoussaine
• Middendorf Claus
• Krieg Harald H

Classifications

• D04H1/45

  by forming intermeshing loops or stitches from some of the fibres · CPC title

• D04H1/54

  by welding together the fibres, e.g. by partially melting or dissolving (in combination with needling D04H1/485) · CPC title

• D04H1/4218

  Glass fibres · CPC title

• D01G9/12

  Combinations of opening or cleaning machines · CPC title

• D04H1/4209

  Inorganic fibres · CPC title