Ngk Insulators, Inc.

Sadaaki Hirai

Yukihito Ichikawa

Yasushi Kato

Takayuki Kawae

Shinzo Hayashi

Takeshi Ngk Insulators Ltd Tokunaga

There are provided a honeycomb structure and a method of manufacturing the honeycomb structure, the honeycomb structure including a honeycomb structural part, which has partition wallsfor forming a plurality of cellspartitioned in a honeycomb shape and for forming recesseson an outer peripheral surface, and an outer wall partdisposed on the outer peripheral surface of the honeycomb structural part, wherein voids are formed in the recessesbetween the outer wall partand the honeycomb structural part. The honeycomb structure and the method of manufacturing the same can suppress the reduction of a temperature increasing speed while suppressing a decrease of mechanical strength and further can suppress the occurrence of cracks.

Honeycomb structural body and method of manufacturing the same

There is provided a cell structure, where the outer wall portion has high heat-insulating ability, the cell structural portion has a high temperature rise rate, and a temperature distribution is more uniform, and a method for manufacturing the cell structure. The cell structureincludes: a cell structural portionhaving partition walls forming a plurality of cells extending from one end face to the other end face, and an outer wall portiondisposed on an outer peripheral surface of the cell structural portionThe outer wall portionhas at least a porous layer having a porosity of 40% or more or a porous layer having a hollow body. The manufacturing method can easily manufacture the cell structure.

Cell structure and method of manufacturing the same

A honeycomb formed article comprising a plurality of partition walls is prepared using clay mainly composed of a ceramic material, a partition wall strengthening agent obtained by mixing a partition wall strengthening material with a dispersion medium mainly composed of an amphipathic liquid compound having both hydrophilic and hydrophobic groups is coated to a plurality of partition walls existing in at least one cell opening end portion of the formed article, and thereafter the article is fired. According to this method, while largely improving enhancement of productivity and product cost reduction, a honeycomb structure superior in isostatic strength and resistance to erosion can be stably obtained.

Method for manufacturing honeycomb structure

The ceramic honeycomb structure according to the present invention includes a cell group having a plurality of cells which are divided each other by porous partition walls and functioning as a fluid channel, and porous outer wall surrounding and holding outermost peripheral cells located at a circumference of the cell group. In the partition walls, a part located at least one opening end of the cells of the cell group constitutes a reinforced partition wall part having higher strength than the other part of the partition walls (normal partition wall part) as well as having a variation of porosity per unit volume within &#xb1;2%. Uniform and excellent erosion resistance is achieved throughout the reinforced partition wall part.

Ceramic honeycomb structural body and method of manufacturing the structural body

The ceramics honeycomb structure of the present invention is formed of a plurality of cells forming a fluid flow passage partitioned by porous partition walls, and comprising an inflow end part allowing fluid to flow therein, an outflow end part allowing fluid to flow therefrom, and an outer peripheral part including an outer peripheral surface, and is characterized by having a structure where a porosity per unit volume (cm) gradually increases from the inflow end part side to the outflow end part side at a rate of 0.2%/mm or less, and this ceramics honeycomb structure has an excellent erosion resistance of partition walls positioned at a cell opening end part and a high compressive strength (isostatic strength) at the time of canning, and is suitable particularly as an automobile exhaust gas purification catalyst carrier.

Ceramics honeycomb structural body and method of manufacturing the structural body

A ceramic heater includes a body of aluminum nitride, and a heating element embedded in the body of aluminum nitride. The heating element has a resistance of (E.sup.2 /W).multidot.0.003.OMEGA. to (E.sup.2 /W).multidot.0.135.OMEGA. (E and W denote an input voltage (unit: V) and a weight (unit: g) of the body of aluminum nitride, respectively).

Ceramic heater

The present invention includes a method for freeze molding, comprising the steps of: mixing poly(vinyl alcohol) or a modified additive thereof with a material slurry to obtain a mixture; pouring the mixture into a molding die; and subjecting the mixture in a molding die to at least one cycle of cooling and heating so as to obtain a compact. A compact obtained in this method is free from melting and can maintain its configuration even if the compact is kept at a temperature of freezing point or higher. Further, since the method does not require vacuum drying, the compact can easily be dried.

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Nagoya, Japan

Sadaaki Hirai