Mounting mat including inorganic nanoparticles and method for making the same

Patent metadata

Field	Value
Publication number	US-9416053-B2
Application number	US-68219608-A
Country	US
Kind code	B2
Filing date	Oct 7, 2008
Priority date	Oct 9, 2007
Publication date	Aug 16, 2016
Grant date	Aug 16, 2016

Abstract

The present invention relates to a mounting mat for mounting a pollution control device in a catalytic converter, the mounting mat comprising a non-woven mat of inorganic fibers having distributed therein inorganic particles having an average diameter of 1 nm to 100 nm and wherein the mounting mat is free of organic binder or contains organic binder in an amount of not more than 5% by weight, based on the total weight of the mounting mat. The invention further relates to a pollution control device including the mounting mat and to a method of making the mounting mat.

First claim

What is claimed is:

1. Mounting mat for mounting a pollution control element in a housing of a pollution control device, the mounting mat comprising a non-woven mat of inorganic fibers having distributed therein intumescent material and inorganic particles having an average diameter of 1 nm to 100 nm, wherein the non-woven mat is suitable for absorbing mechanical and thermal shock as well as compensating for thermal expansion differences between the pollution control element and the housing, and the mounting mat is free of organic binder or contains organic binder in an amount of not more than 5% by weight, based on the total weight of the mounting mat.

2. Mounting mat according to claim 1 , wherein the inorganic particles are contained in said non-woven mat in an amount in the range of from at least 0.5% to 10% by weight.

3. Mounting mat according to claim 1 , wherein the intumescent material comprises vermiculite ore, graphite, sodium silicate or combinations thereof.

4. Mounting mat according to claim 3 , further comprising one or more layers selected from scrims and nettings wherein said mounting mat is an intumescent mounting mat.

5. Mounting mat according to claim 1 , wherein the inorganic fibers are selected from melt formed ceramic fibers including annealed melt-formed ceramic fibers, sol-gel formed ceramic fibers, polycrystalline fibers, glass fibers including heat treated glass fibers, alumina-silica fibers, biosoluble fibers, and combinations thereof.

6. Mounting mat according to claim 1 , wherein said mounting mat is needle-punched or stitch-bonded.

7. Mounting mat according to claim 1 , further comprising one or more layers selected from scrims and nettings.

8. Mounting mat according to claim 7 , wherein the scrim or netting comprises inorganic fibers.

9. Mounting mat according to claim 1 , wherein the inorganic particles comprise oxides of silica, alumina or zirconia, titania or silicates.

10. Pollution control device having a housing, a pollution control element disposed within the housing, and a mounting mat disposed between the pollution control element and the housing for positioning the pollution control element and for absorbing mechanical and thermal shock, wherein the mounting mat comprises a mounting mat as defined in claim 1 .

11. A method of making a mounting mat as defined in claim 1 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) capturing clumps of fibers on a lower run of the endless belt beneath fiber separating rollers and above the forming wire;
(iii) 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;
(iv) transporting the mat of fibers out of the forming box by the forming wire; and
(v) compressing the mat of fibers and restraining the mat of fibers in its compressed state thereby obtaining a mounting mat having a desired thickness suitable for mounting a pollution control element in the housing of a catalytic converter;
wherein inorganic particles having an average diameter of 1 nm to 100 nm are provided in the mounting mat.

12. A method according to claim 11 , wherein the inorganic particles are provided in the mounting mat by supplying a powder of inorganic particles to the forming box.

13. A method according to claim 11 , wherein the inorganic particles are provided in the mounting mat by spraying a dispersion of the inorganic particles on the inorganic fibers before supplying the inorganic fibers to the forming box or by spraying the dispersion on the mat of fibers before or after compression thereof.

14. Mounting mat according to claim 1 , wherein said inorganic particles are evenly distributed within said non-woven mat.

15. Mounting mat according to claim 14 , wherein said non-woven mat further contains an intumescent material.

16. Mounting mat according to claim 15 , wherein said mounting mat is an intumescent mounting mat.

17. Pollution control device having a housing, a pollution control element disposed within the housing, and a mounting mat disposed between the pollution control element and the housing for positioning the pollution control element and for absorbing mechanical and thermal shock, wherein the mounting mat comprises a mounting mat as defined in claim 16 .

18. Mounting mat according to claim 14 , wherein the inorganic particles comprise oxides of silica, alumina or zirconia, titania or silicates.

19. Pollution control device having a housing, a pollution control element disposed within the housing, and a mounting mat disposed between the pollution control element and the housing for positioning the pollution control element and for absorbing mechanical and thermal shock, wherein the mounting mat comprises a mounting mat as defined in claim 14 .

20. Mounting mat according to claim 1 , wherein the non-woven mat contains more of the inorganic fibers by weight than the inorganic particles.

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

• C04B30/02 Primary

  containing fibrous materials · CPC title

• F01N3/10

  by thermal or catalytic conversion of noxious components of exhaust · CPC title

• F01N3/20

  specially adapted for catalytic conversion (F01N3/22 takes precedence) · CPC title

• D04H1/46

  by needling or like operations to cause entanglement of fibres (D04H1/45 takes precedence; needling machines D04H18/00) · CPC title

• D04H1/4209

  Inorganic fibres · CPC title