Ceramic Honeycomb Plugging via Variable Mask Holes

Solution Overview

Problem

In the manufacturing of ceramic honeycomb structures used in filters like diesel particulate filters, the uniformity of plugging slurry length into cells is often compromised due to equal-sized holes in the masking film, leading to non-uniform pressure loss and deposition variations across cells.

Innovation Solution

A method involving the creation of holes with different diameters in the masking film ensures controlled and uniform plugging slurry length into cells by varying hole diameters based on cell position, using an automatic control system to adjust hole diameters for optimal slurry distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If holes of equal diameter are made in the masking film, then the manufacturing process is simple, but the plugging slurry length becomes non-uniform across cells

Engineering Contradiction:

Improvemasking film hole fabrication simplicityVSAvoidplugging slurry length uniformity

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies local quality by varying the hole diameters in the masking film according to the position of cells. Cells at different locations (center vs. periphery) have different hole diameters assigned to them, allowing the plugging slurry to be pressed to uniform depth across all cells despite their different positions in the honeycomb structure.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the parameter of hole diameter in the masking film from a constant value to a variable value that depends on cell position. By adjusting the hole diameter parameter locally for different cells, the system achieves uniform plugging slurry length while maintaining manufacturing feasibility.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If uniform plugging slurry length is achieved, then pressure loss and deposition become uniform, but the masking film requires complex hole diameter variations

Engineering Contradiction:

Improveplugging slurry length uniformityVSAvoidmasking film hole configuration

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies local quality by varying the hole diameters in the masking film according to the position of cells. Cells at different locations (center vs. periphery) have different hole diameters assigned to them, allowing the plugging slurry to be pressed to uniform depth across all cells despite their different positions in the honeycomb structure.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent employs feedback by determining hole diameters based on the relationship between cell position and desired plugging depth. The system calculates the appropriate hole diameter for each cell location to compensate for positional effects, ensuring uniform plugging results through a controlled variation pattern.

Inventive Principle:

Principle #23Feedback

3Ease of manufacture

If equal diameter holes are used in the mask, then the mask fabrication is straightforward, but pressure loss fluctuates across cells

Engineering Contradiction:

Improvemask fabrication easeVSAvoidpressure loss consistency

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent applies local quality by varying the hole diameters in the masking film according to the position of cells. Cells at different locations (center vs. periphery) have different hole diameters assigned to them, allowing the plugging slurry to be pressed to uniform depth across all cells despite their different positions in the honeycomb structure.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the parameter of hole diameter in the masking film from a constant value to a variable value that depends on cell position. By adjusting the hole diameter parameter locally for different cells, the system achieves uniform plugging slurry length while maintaining manufacturing feasibility.

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

This approach achieves uniform plugging slurry lengths across cells, reducing pressure loss fluctuations and deposition variations, thereby enhancing the performance and consistency of ceramic honeycomb filters.

Implementation Method 1

pressing the end surface so that the plugging slurry is pressed into the openings of the predetermined cells through the holes of the film

Methodology Applied

Scientific EffectPressure: Pressure Increase

Data Source

PatentUS7727459B2Method of manufacturing ceramic honeycomb structure

Publication Date: 2010.06.01 NGK INSULATORS LTD

AI summary

There is disclosed a method of manufacturing a ceramic honeycomb structure, which is capable of controlling a length of slurry pressed into each cell of the honeycomb structure when predetermined cells are plugged at an end surface of the honeycomb structure. A film 4 is attached to an end surface of the honeycomb structure 1. Holes 3a, 3b through the film 4 are made at a position corresponding to openings of predetermined cells 2a, 2b. The end surface is immersed into slurry 6 stored in a container 5 and the end surface is pressed so that the slurry 6 is pressed into the openings of the predetermined cells 2a, 2b. When the holes are made, two or more types of holes 3a, 3b having different diameters are made.