Cordierite Honeycomb Filter Plug Bonding via Controlled Sintering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for producing ceramic honeycomb filters face challenges such as deformation of unsintered ceramic moldings, insufficient plug length, and low bonding strength between plugs and cell walls due to sintering shrinkage, leading to longer production times and higher costs.
Innovation Solution
A method involving high-speed temperature elevation and controlled cooling during sintering of cordierite-based ceramic honeycomb filters, with a temperature-elevating speed of 70-500°C/hr and a temperature-lowering speed of 30-400°C/hr, ensures strong bonding of plugs to cell walls by adhering them before shrinkage occurs, using a cordierite-forming material with 5-22% silica by mass and sintering in a continuous furnace.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If plugs are formed by charging unsintered plugging material into unsintered ceramic honeycomb molding, then plug formation is simple, but the molding deforms due to water intrusion and plug length becomes insufficient
Solution Approach 1:
The ceramic honeycomb molding is sintered to completion before plug formation. This preliminary sintering action stabilizes the molding structure, preventing subsequent deformation when plugs are formed, while still allowing simple plug charging into the pre-sintered structure.
Solution Approach 2:
The formation timing parameter is changed from post-sintering (invention) to pre-sintering (prior art). By forming plugs after the molding is fully sintered, the material state changes from unsintered to sintered, eliminating water intrusion issues while maintaining manufacturing simplicity.
2Manufacturing precision
If plugs are formed by charging unsintered plugging material into sintered ceramic honeycomb structure, then molding deformation is avoided, but bonding strength becomes insufficient due to sintering shrinkage differences
Solution Approach 1:
The sintering temperature parameter is increased to 1400-1500°C, and the sintering time is extended to 2-6 hours. This parameter change ensures that the plugs and cell walls undergo similar sintering shrinkage, achieving sufficient bonding strength while maintaining dimensional stability.
Solution Approach 2:
The plugging material is designed as a composite containing cordierite particles (5-22% by mass) combined with binder and pore-forming agent. This composite formulation matches the thermal expansion and shrinkage characteristics of the cell walls, enabling strong bonding after sintering.
3Strength
If conventional sintering temperature and time are used, then plugs achieve sufficient bonding, but production time becomes excessively long
Solution Approach 1:
The sintering temperature parameter is optimized to 1400-1500°C (higher than conventional) and sintering time is reduced to 2-6 hours (shorter than conventional). This parameter optimization achieves sufficient bonding strength while significantly reducing production time through accelerated sintering kinetics.
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
This approach ensures reliable and efficient bonding of plugs to cell walls, reducing the likelihood of detachment and improving particulate matter capture efficiency while shortening sintering time and reducing production costs.
Implementation Method 1
drying and sintering the resultant plugs, the sintering step comprising a temperature-elevating process, a temperature-keeping process and a temperature-lowering process
Implementation Method 2
the plugs undergoes dimensional change such as shrinkage and expansion by a sintering reaction
Data Source
AI summary
A method for producing a cordierite-based ceramic honeycomb filter comprising the steps of introducing a plugging material of a cordierite-forming material into predetermined flow paths of a sintered, cordierite-based ceramic honeycomb having an outer diameter of 150 mm or more, and drying and sintering the resultant plugs, the sintering step comprising a temperature-elevating process, a temperature-keeping process and a temperature-lowering process, and the temperature-elevating process having a temperature-elevating speed of 70-500° C./hr from 800° C. to the highest keeping temperature.