Honeycomb Structure Bonding with Layered Clay Mineral

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Solution Overview

Problem

Conventional ceramic honeycomb structures face issues with bonding defects such as cracking and displacement due to nonuniform bonding and stress concentration, which affect the durability of the structure.

Innovation Solution

A ceramic honeycomb structure is developed using a bonding material containing 0.1 to 10 mass% of layered smectite clay mineral, along with an organic binder, and specific rheological properties to ensure uniform bonding and enhanced bonding strength between honeycomb segments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If pressure and vibration are applied to each porous honeycomb segment successively, then the segments can be bonded together, but the transmitted force acts as a peeling force on lower segments causing adhesive layer peeling and bonding strength decrease

Engineering Contradiction:
Improvebonding processVSAvoidbonding strength
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent combines multiple bonding operations into a single simultaneous pressurizing step. Instead of bonding segments one by one with separate pressure and vibration applications, the invention presses all honeycomb segments simultaneously in one operation, merging the bonding process to eliminate cumulative peeling forces on lower segments.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent inverts the conventional bonding approach by pressing from the outermost peripheral layer inward rather than bonding segments sequentially from bottom to top. This reversal of the bonding sequence prevents the cumulative peeling effect that occurs when each new segment adds stress to previously bonded lower segments.

Inventive Principle:
Principle #13The other way round (Inversion)

2Ease of manufacture

If a load is applied to flatten out the bonding material, then the honeycomb segments can be bonded, but the bonding material requires fluidity and may contract or displace before bonding strength develops

Engineering Contradiction:
Improvebonding processVSAvoidbonding width uniformity
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies pressurizing force before the bonding material fully sets and develops strength. By pressing all segments simultaneously while the bonding material is still pliable, the load distributes uniformly across all bonding interfaces at once, preventing subsequent contraction or displacement that would occur if pressing were delayed until after initial bonding.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent controls the rheological parameters of the bonding material, specifically its fluidity and contraction ratio, to optimize bonding performance. By adjusting these material parameters, the bonding material maintains appropriate fluidity during pressing to allow uniform distribution, then minimizes contraction after pressing to prevent bonding width fluctuations.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If bonding material with high fluidity is used to allow load application, then segments can be pressed together, but bonding width fluctuates and displacement occurs before bonding strength develops

Engineering Contradiction:
Improvebonding processVSAvoidbonding width uniformity
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent optimizes the rheological parameters of the bonding material, specifically controlling its fluidity and contraction ratio. By adjusting these parameters, the material has sufficient fluidity to distribute uniformly under pressurizing load, yet maintains enough stability to minimize contraction and displacement after pressing, thereby achieving both ease of manufacture and bonding width uniformity.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution effectively suppresses bonding width fluctuations and displacements, ensuring secure bonding without cracks or peeling, thereby improving the durability and reliability of the honeycomb structure.

Implementation Method 1

a layered clay mineral which has a fluidity suppressing effect

Methodology Applied
Scientific EffectFluidity suppression effect of layered clay mineral: Montmorillonite

Implementation Method 2

integrating a plurality of honeycomb segments by bonding the outer walls of the respective honeycomb segments to one another with a bonding material

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP2006264B1Honeycomb structure and method for producing same
Publication Date: 2013.04.03 NGK INSULATORS LTD
  • EP2006264B1 patent drawingFigure 1(a)~1(b)
  • EP2006264B1 patent drawingFigure 1(c)~2(b)
  • EP2006264B1 patent drawingFigure 2(c)

AI summary

Disclosed is a honeycomb structure which is bonded with a bonding material containing 0.1 to 10 mass% of a layered clay mineral. Also disclosed are a honeycomb structure which is bonded with a bonding material containing 0.1 to 10 mass% of an organic binder, and a honeycomb structure which is bonded with a bonding material having a Casson yield value of 6 Pa or more. Further disclosed is a method for producing such a honeycomb structure.