Unifrax I LLC

Unifrax Corporation

Unifax I LLC

Thomas S Lacki

Amit Kumar

Joseph A Fernando

John D Ten Eyck

John D Teneyck

Digvijay Singh Chauhan

A mounting mat for an exhaust gas treatment device includes a wet laid sheet of polycrystalline inorganic fibers that have been physically entangled while the wet laid sheet is still in a wet condition. The exhaust gas treatment device includes a housing, a fragile catalyst support structure resiliently mounted within the housing, and the mounting mat disposed in a gap between the housing and the fragile structure. Additionally disclosed are methods of making a mounting mat for an exhaust gas treatment device and for making an exhaust gas treatment device incorporating the mounting mat.

Mounting mat for exhaust gas treatment device

Methods of forming insulation mats including: providing a mixture of fibers comprising first inorganic fibers and second inorganic fibers, wherein the first inorganic fibers shrink by no more than about 2 percent and the second fibers shrink by about 5 to about 15 percent when the mixture of fibers is heat treated; wet-forming a web of fibers from the mixture of fibers; entangling the web of fibers to form an insulation mat; heat-treating the insulation mat; and drying the web of fibers and/or the insulation mat after said wet-forming and prior to or during said heat treating; and wherein the insulation mat includes substantially no non-fibrous binder material prior to said heat treating the insulation mat at a temperature of from about 500&#xb0; C. to about 800&#xb0; C., optionally for at least about 3 minutes. Insulation mats manufactured according to the above methods.

High temperature resistant insulation mat

A mounting mat for an exhaust gas treatment device including inorganic fibers, organic binder, high temperature resistant inorganic microspheres, and optionally intumescent material. The exhaust gas treatment device includes a housing, a fragile catalyst support structure resiliently mounted within the housing, and the mounting mat disposed in a gap between the housing and the fragile catalyst support structure.

Use of microspheres in an exhaust gas treatment device mounting mat

A support element is disposed between a housing and a fragile structure resiliently mounted within the housing. The support element includes an integral, substantially non-expanding ply or layer of melt-formed ceramic fibers containing at least alumina and silica. The fibers have an average diameter ranging from about 1 micron to about 14 microns and have been prepared by a process of heat treating under a time-temperature regimen of one of (i) heat treating said fibers at a temperature of 990&#xb0; C. to at least 1050&#xb0; C. for greater than 1 hour such that the treated fibers have about 5 to about 50 percent crystallinity as detected by x-ray diffraction, and a crystallite size of about 50 &#x212b; to about 500 &#x212b;, or (ii) heat treating said fibers at a temperature of greater than 1050&#xb0; C. for an effective time such that the treated fibers have about 5 to about 50 percent crystallinity as detected by x-ray diffraction, and a crystallite size of about 50 &#x212b; to about 500 &#x212b;. The resultant support element provides a minimum residual pressure for holding the fragile structure within the housing of one of at least 4 psi after at least 200 cycles of testing at 900&#xb0; C. or at least 10 psi after at least 1000 cycles of testing at 750&#xb0; C. Such a support element may be used in devices for the treatment of exhaust gases such as catalytic converters, diesel particulate traps and the like. A method of mounting a fragile structure in such a device is also provided.

Support element for fragile structures such as catalytic converters

A device () for treatment of exhaust gases includes a housing (); a fragile structure () resiliently mounted within the housing (); and a non-intumescent mounting mat () disposed in a gap between the housing () and the fragile structure (). The mounting mat () comprises melt-formed, leached glass fibers high in silica content and exerts a minimum holding pressure for holding the fragile structure () within the housing () of one of (i) at least 10 kPa after 1000 cycles of testing at a hot face temperature of 900&#xb0; C., a gap bulk density of between 0.3 and 0.5 g/cm, and a percent gap expansion of 5 percent, and (ii) at least 50 kPa after 1000 cycles of testing at a hot face temperature of 300&#xb0; C., a gap bulk density of between 0.3 and 0.5 g/cm, and a percent gap expansion of 2 percent.

Growing community of inventors

Alden, NY, United States of America

Thomas S Lacki