Plugged Honeycomb Structure Manufacturing Method
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Solution Overview
Problem
The existing methods for manufacturing honeycomb structures with plugged cells, such as diesel particulate filters, face challenges in suppressing the counterflow of plugging slurry during the manufacturing process, particularly when both end faces are plugged simultaneously, leading to potential formation of through holes in areas intended to be plugged.
Innovation Solution
A method where the honeycomb structure is horizontally held along the longitudinal direction of cells, with large cells plugged at one end face and small cells plugged at the other end face, allowing a controlled time difference of 0.3 seconds or more between the plugging of large and small cells, and ensuring a sectional area ratio of 1.21 or more between the two types of cells, while maintaining a plugging slurry viscosity of 500 dPa·s or less.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If both end faces of the honeycomb structure are simultaneously subjected to plugging, then the manufacturing time is shortened, but the plugging slurry flows backwards from cells with large sectional areas causing through holes to form in portions intended to be plugged
Solution Approach 1:
The plugging process is segmented into two distinct stages: first plugging large cells, then plugging small cells. This segmentation prevents slurry counterflow by completing the large cell plugging before introducing slurry for small cells, thereby maintaining plugging quality while enabling simultaneous processing of both end faces
Solution Approach 2:
The mask for small cells is attached in advance before the plugging process begins. This preliminary action ensures that the mask is properly positioned and ready, allowing the plugging operation to proceed efficiently without delays while maintaining precise control over slurry flow into small cells
2Reliability
If the plugging slurry viscosity is increased to suppress counterflow, then the slurry flows more slowly, but the plugging process time increases and manufacturing efficiency decreases
Solution Approach 1:
The mask for small cells is attached beforehand, creating a controlled environment that prevents slurry counterflow without requiring high viscosity. This preliminary preparation allows the use of lower viscosity slurry that flows quickly while still preventing backward flow through proper mask positioning and timing
Solution Approach 2:
By segmenting the plugging process into sequential stages (large cells first, then small cells), the system maintains reliable counterflow suppression through process timing rather than relying on high slurry viscosity, thereby enabling faster plugging with lower viscosity materials
Data Source
Figure 1(A)~2
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AI summary
Disclosed is a method for quickly and correctly manufacturing a honeycomb structure constituted of two types of cells including large cells each having a relatively large area of a section thereof vertical to a longitudinal direction and small cells each having a relatively small area of the section. The method is a manufacturing method of a honeycomb structure including a large number of cells arranged via partition walls, the cells being constituted of two types of cells including large cells each having a relatively large area of a section thereof vertical to a longitudinal direction and small cells each having a relatively small area of the section, the large cells being plugged in one end face of the honeycomb structure and the small cells being plugged in the other end face of the honeycomb structure. The method horizontally holds the honeycomb structure before the plugging along the longitudinal direction of the cells, first plugs the large cells, and continuously plugs the small cells.