Honeycomb Structure Bonding Layer Micro-Pore Formation
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Solution Overview
Problem
Conventional honeycomb structures used in exhaust gas treating apparatuses suffer from reduced strength due to the formation of macro pores in the bonding and coating layers, which can lead to cracking and damage under stress.
Innovation Solution
Incorporating particles of a foaming material with diameters between 1 µm to 50 µm into the bonding and coating layers, which expand and evaporate to form micro pores instead of macro pores, thereby enhancing the structural integrity of the honeycomb structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If moisture is allowed to penetrate into the honeycomb unit during drying, then the paste volume decreases, but large bubbles form to compensate, creating macro pores that weaken the structure
Solution Approach 1:
The patent introduces a foaming agent into the paste that creates controlled micro-pores during drying. These micro-pores replace the harmful macro-pores that would otherwise form due to moisture penetration and subsequent bubble formation. The foaming agent systematically creates a porous structure at the micro-scale that maintains paste volume stability while preventing the formation of large bubbles that compromise bonding layer strength.
Solution Approach 2:
The patent changes the physical parameters of the paste by adding a foaming agent that alters the bubble formation characteristics. Instead of allowing large bubbles to form naturally when moisture penetrates, the foaming agent modifies the paste properties to generate numerous small bubbles that evaporate into micro-pores. This parameter change transforms the harmful macro-pore formation process into a beneficial micro-pore structure that preserves both volume stability and bonding strength.
2Volume of stationary object
If the paste volume decreases due to moisture penetration, then the space between honeycomb units must be compensated, but this compensation creates large bubbles and macro pores
Solution Approach 1:
The foaming agent systematically creates a controlled porous structure within the paste before drying. This pre-formed porous structure allows the paste to accommodate volume changes due to moisture penetration without forming large bubbles. The micro-pores created by the foaming agent provide internal void space that compensates for volume reduction, eliminating the need for large bubble formation and thus maintaining manufacturing precision in terms of bubble size control.
Solution Approach 2:
The foaming agent performs a preliminary action by creating micro-pores in advance during the paste application stage, before drying occurs. This preliminary pore structure is prepared so that when moisture penetration and subsequent drying occur, the paste has already established a controlled porous framework that prevents large bubble formation. The preliminary action of foam creation precedes and prevents the harmful macro-pore formation that would otherwise occur during drying.
3Stability of the object's composition
If macro pores are formed in the bonding layer, then the structure can accommodate volume changes, but the strength deteriorates considerably
Solution Approach 1:
The patent systematically replaces harmful macro-pores with beneficial micro-pores created by the foaming agent. The micro-porous structure provides the necessary volume accommodation capability while maintaining structural integrity. The controlled micro-pore distribution allows the bonding layer to accommodate volume changes during drying and firing without the formation of large voids that would compromise strength, thus resolving the contradiction between volume stability and strength.
Solution Approach 2:
The patent changes the pore size parameter from macro-scale to micro-scale through the use of a foaming agent. This parameter change transforms the pore structure from harmful large voids to beneficial small micro-pores. The micro-pore structure maintains the volume accommodation function while dramatically improving strength by eliminating the stress concentration points and crack propagation pathways associated with macro-pores.
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 method prevents the formation of macro pores, improving the strength and durability of the honeycomb structure by creating a layer with micro pores, reducing the likelihood of cracking and enhancing the structure's ability to withstand stress.
Implementation Method 1
wherein said particles of a foaming material expand and evaporate, thereby forming micro pores
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
A method of producing a honeycomb structure (100) includes a step of forming a ceramic block (140) by bonding a plurality of honeycomb units (130) that have a plurality of cells (22) partitioned by cell walls (23) using a bonding layer (110) or, a step of forming a ceramic block (140) by a single honeycomb unit (130) that has a plurality of cells (22) partitioned by cell walls (23), and a step of providing a coating layer (120) on an outer peripheral portion of the ceramic block (140), and is characterized by a step of providing a paste of the bonding material including particles of a foaming material having a diameter in a range of 1 µm to 50 µm on each bonding surface of each honeycomb unit (130), and/or, a step of providing a paste of a coating material including particles of a foaming material having a diameter in a range of 1 µm to 50 µm on the outer peripheral portion of the ceramic block (140), a step of blowing up the foaming material, and a step of evaporating the foaming material and forming bubble marks having a diameter in a range of 100 µm to 300 µm.