Ceramic Honeycomb Batch Composition for Extrusion Shape Control
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Solution Overview
Problem
Conventional batch compositions for ceramic honeycomb bodies face challenges in achieving high extrusion feed rates while maintaining good shape control and quality, with low Tau Y/Beta ratios and issues like wall defects and slumping due to water micro-segregation.
Innovation Solution
A batch composition comprising pre-reacted inorganic spheroidal particles with a narrow particle size distribution and non-hydrophilic pore-former spheroidal particles, which are combined with a controlled amount of fine inorganic particles and an organic binder, to form a paste that is extruded into a green honeycomb body, then dried and fired to produce a ceramic honeycomb body with improved rheological properties and reduced shrinkage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional batch compositions are used for extrusion, then manufacturing process is simple, but Tau Y/Beta ratio is low causing poor shape control and wall defects
Solution Approach 1:
The patent changes the particle size distribution parameters of the inorganic powder, specifically using a narrow particle size distribution with D10-D90 range of 15-45 μm and mean particle size of 20-40 μm. This parameter optimization improves the Tau Y/Beta ratio to 3.0 or more, enabling excellent shape control and eliminating wall defects during extrusion while maintaining manufacturing simplicity
Solution Approach 2:
The patent creates a composite batch composition by combining specifically sized inorganic particles (narrow distribution 20-40 μm) with organic binders and pore-forming agents. This composite structure optimizes both the rheological properties (Tau Y/Beta ratio) and the final honeycomb body quality, resolving the contradiction between ease of manufacture and manufacturing precision
2Productivity
If extrusion feed rate is increased to improve productivity, then production efficiency increases, but shape control and quality deteriorate
Solution Approach 1:
The patent optimizes the particle size distribution parameters (narrow distribution with D10-D90 of 15-45 μm and mean size of 20-40 μm) to achieve a high Tau Y/Beta ratio of 3.0 or more. This rheological optimization allows the extrusion process to maintain excellent shape control and quality even at high feed rates, thereby improving productivity without sacrificing manufacturing precision
3Ease of operation
If water is added to batch composition to improve plasticity, then ease of extrusion increases, but water micro-segregation occurs causing wall defects
Solution Approach 1:
The patent changes the fundamental parameter of particle size distribution to a narrow range (D10-D90: 15-45 μm, mean: 20-40 μm), which optimizes the interface between water and inorganic particles. This prevents water micro-segregation while maintaining adequate plasticity for extrusion, thereby improving ease of operation without compromising wall quality
Solution Approach 2:
The patent develops a composite batch composition where specifically sized inorganic particles (narrow distribution) are combined with organic binders and pore-forming agents. This composite structure ensures uniform water distribution throughout the batch, preventing micro-segregation and wall defects while maintaining the necessary plasticity for easy extrusion
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 achieves high Tau Y/Beta ratios, resulting in excellent extrusion properties, low wall and cell distortion, smooth finish, and minimal shrinkage, enabling faster extrusion rates with maintained shape control and quality.
Implementation Method 1
pre-reacted inorganic spheroidal particles having a pre-reacted particle size distribution wherein: and and pore-former spheroidal particles having a pore-former particle size distribution wherein: and
Implementation Method 2
Such ceramic honeycomb bodies may be manufactured by extruding a plasticized batch composition of inorganic and organic materials and a liquid vehicle (LV), such as deionized water, through an extrusion die of an extruder
Implementation Method 3
The batch composition comprises less than 20% of fine inorganic particles based on a total weight of the pre-reacted inorganic spheroidal particles, wherein the fine inorganic particles have a median diameter of less than 5 μm
Implementation Method 4
Cordierite, silicon carbide, and aluminum titanate-containing ceramic honeycomb bodies have been used in catalytic converters and particulate filters for diesel and gasoline engine exhaust after-treatment
Data Source
Figure 1~3
Figure 4A~4B
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AI summary
A batch composition containing pre-reacted inorganic spheroidal particles and pore- former spheroidal particles. The pre-reacted inorganic spheroidal particles have a particle size distribution wherein 10 µm ≤ DI50 < 50 µm, and DIb ≤ 2.0, and the pore-former spheroidal particles have a particle size distribution wherein 0.40 DP50 ≤ DI50 < 0.90 DP50, and DPb ≤ 1.32, wherein DI50 is a median particle diameter of the distribution of pre-reacted inorganic spheroidal particles, DP50 is a median particle diameter of the pore-former particle size distribution, DIb is a breadth factor of the pre-reacted particle size distribution of the pre- reacted inorganic spheroidal particles, and DPb is a breadth factor of the pore-former particle size distribution. Also, green honeycomb bodies manufactured from the batch compositions, and methods of manufacturing a honeycomb body using the batch compositions, are provided.