SiC Honeycomb Filter Bonding Without Organic Binders
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional diesel particulate filters face issues with bonding strength, durability, and thermal stress resistance due to oxidation of silicon carbide honeycomb segments, which can lead to filter destruction and increased PM emissions.
Innovation Solution
Forming an oxidation layer on silicon carbide honeycomb segments and bonding them using a sealing material composed of silicon carbide powder, ceramic fibers, and an inorganic binder, without organic binders, to enhance bonding strength and thermal shock resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If silicon carbide honeycomb segments are bonded using conventional sealing materials, then the filter can be assembled, but the bonding strength is insufficient and thermal shock resistance is poor
Solution Approach 1:
The patent changes the chemical composition parameters of the sealing material by incorporating silicon carbide powder with specific particle size distributions (D10: 0.5-2 μm, D50: 2-5 μm, D90: 5-10 μm) and controlling the water-to-binder ratio, which fundamentally alters the bonding characteristics and thermal resistance properties of the sealant
Solution Approach 2:
The sealing material is formulated as a composite system combining inorganic binder, water, and silicon carbide powder in specific proportions, creating a multi-phase material that simultaneously provides bonding strength, thermal stability, and shock resistance through the synergistic effects of its components
2Ease of manufacture
If organic binders are used in the sealing material to improve bonding, then assembly is easier, but durability and thermal stress resistance deteriorate
Solution Approach 1:
The patent completely removes organic binders from the sealing material composition, extracting the harmful element that causes durability issues while maintaining manufacturability through the inorganic binder system that provides adequate workability and bonding without organic additives
Solution Approach 2:
The patent replaces long-lived organic binders with an inorganic binder system that, while requiring precise mixing ratios, provides superior long-term durability and thermal stability, effectively trading short-term manufacturing complexity for long-term operational reliability
3Stability of the object's composition
If the honeycomb segments are not oxidized, then the original material properties are preserved, but bonding strength and thermal shock resistance are reduced
Solution Approach 1:
The patent applies preliminary oxidation treatment to the silicon carbide honeycomb segments before bonding, creating a surface layer that enhances bonding strength and thermal shock resistance. This pre-treatment prepares the surface in advance to receive the sealing material more effectively
Solution Approach 2:
The oxidation process changes the surface chemical composition parameters of the silicon carbide segments, creating a modified surface layer with different properties than the bulk material, thereby improving bonding characteristics without fundamentally altering the core material composition
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 results in a honeycomb structural body with improved bonding strength, thermal shock resistance, and durability, effectively maintaining performance during regeneration processes and operations.
Implementation Method 1
bonding them using a sealing material composed of silicon carbide powder, ceramic fibers, and an inorganic binder
Implementation Method 2
Forming an oxidation layer on silicon carbide honeycomb segments and bonding them using a sealing material... to enhance bonding strength and thermal shock resistance
Data Source
Figure 1~2
Figure 3~4
AI summary
The invention relates to a honeycomb structural body and to a method for the manufacturing thereof. The manufacturing method comprises the steps of (i) providing a plurality of silicon carbide honeycomb segments each having a cell structure and at least one outer wall, (ii) subjecting said honeycomb segments to an oxidizing thermal treatment forming a surface layer of silicon oxides on said at least one outer wall, and (iii) bonding said plurality of oxidized honeycomb segments so as to form said honeycomb structural body in the substantial absence of organic binders with the interposition of a sealing material comprising a mixture of one or more silicon carbide powder, one or more ceramic fiber, and one or more inorganic binder