Sichuan Hersbit Scientific and Technical Co,.Ltd.
Application Research of Hydroxypropyl Methylcellulose (HPMC) in the Preparation of Honeycomb Ceramic Carriers
As a high-performance structured ceramic material, honeycomb ceramics, with their unique interconnected channels, high specific surface area, and excellent mechanical and thermal stability, have become core components in high-end fields such as automotive exhaust purification, industrial catalysis, and chemical separation.
The realization of their performance is highly dependent on a precise and stable fabrication process.
This article systematically analyzes the industrial fabrication process of honeycomb ceramics and its material processing characteristics.
Flowchart of honeycomb ceramic manufacturing process
The main methods for preparing honeycomb ceramics include extrusion molding, slip casting, and pressing.
Extrusion molding has the advantages of producing products with a height or length much larger than their cross-section, uniform pore size and shape, good wall thickness consistency, relatively simple and easy operation, and the ability to achieve continuous production with high efficiency. Therefore, extrusion molding is widely used in the industrial production of honeycomb ceramics.
batching → mixing → kneading → coarse clay refining → aging → sieving → refining clay → extrusion molding → cutting → drying → sintering.
Carrier material and product shape
Main materials: include cordierite, aluminum titanate, silicon carbide, zirconium oxide, silicon nitride, corundum, mullite, quartz, etc., or it can be a combination of two or more of them.
The shapes of honeycomb ceramics include: corrugated, triangular, square, round, and hexagonal holes.
Preparation of main excipients
In extrusion molding, ceramic powder itself lacks plasticity and must rely on a series of functional additives to construct a suitable clay system for processing. Besides solvents (water or organic solvents), the main auxiliary materials include:
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Catogary
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Main functions
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Representative substances
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Adhesive
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It improves the powder forming ability; imparts mechanical strength to semi-finished products; forms a three-dimensional network to encapsulate particles during the wet process; and regulates drying moisture to reduce deformation and cracking.
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Hydroxypropyl methylcellulose (HPMC)
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plasticizer
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It imparts good plasticity, softness and shape retention to the powder.
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Glycerin, polyethylene, ethylene glycol, etc.
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Degumming agent
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Adjusting the system pH and surface charge facilitates powder dispersion.
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Fish oil, oleic acid, etc.
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lubricant
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Improves demolding performance; enhances the flowability between powder particles.
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Paraffin, stearic acid, etc.
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wetting agent
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Reduces the surface tension of powders; improves wettability.
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Polyether, ethanol, etc.
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Defoamer
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Remove and prevent air bubbles in the powder system.
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Wax emulsions, n-butanol, ethanol, etc.
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Application Industry Classification
Starting with catalyst carriers for purifying automotive exhaust gases, honeycomb ceramic technology has developed rapidly and is widely used in:
Environmental Protection and Energy: Catalyst carriers for automobile and diesel engine exhaust purification (SCR, GPF, DPF, TWC, ASC), and catalytic purification carriers for industrial waste gas (VOCs).
Conclusion
The preparation of honeycomb ceramics is a systematic engineering project involving materials science, rheology, and thermodynamics.
Among these, the precise selection and formulation optimization of HPMC (High-Performance Hybrid Cellulose Monomer) is a crucial bridge connecting ideal design with stable mass production.
As honeycomb ceramics develop towards higher performance and more complex structures, more precise functional requirements are being placed on core additives such as HPMC.
A deep understanding of the role and mechanism of HPMC in each step of the process is of paramount importance for advancing and expanding the application of honeycomb ceramic technology.
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