Inorganic Mold Composition for Casting Gas Defects

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Solution Overview

Problem

Conventional casting mold technologies face challenges in moldability, weight reduction, disposal of spent molds, gas defects in castings due to combustion gases, and surface smoothness issues.

Innovation Solution

A mold composition comprising inorganic particles, inorganic fibers, and layered clay minerals, with specific particle and fiber content ranges, and a method involving mixing and heat-pressing to create a structure that minimizes gas defects and enhances surface smoothness and shape retention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If conventional sand molds are used with organic binders, then shape retention is improved, but gas defects occur due to combustion gases from organic matter

Engineering Contradiction:
Improveshape retentionVSAvoidgas defects
Core Design Contradiction:
ShapeVSObject-generated harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters by replacing organic binders with inorganic binders (water glass, alumina, magnesia). This substitution eliminates the combustion gas generation while maintaining the binding and shape retention functions through inorganic chemical reactions and adhesion mechanisms.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs disposable inorganic binder materials that are applied in thin layers and consumed during the casting process. These inorganic binders serve their binding function and then decompose or vaporize without producing harmful combustion gases, effectively replacing persistent organic binders.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Productivity

If conventional sand molds are used, then casting production is achieved, but surface smoothness is poor

Engineering Contradiction:
Improvecasting productionVSAvoidsurface smoothness
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent creates a composite mold material system combining inorganic particles (silica sand, graphite) with inorganic binders (water glass, alumina). This composite structure provides both the mechanical strength needed for production and the surface properties required for smooth casting surfaces, eliminating the need for separate coating processes.

Inventive Principle:
Principle #40Composite materials

3Ease of manufacture

If organic fiber and thermosetting resin are used in molded articles, then moldability is improved, but weight reduction is limited

Engineering Contradiction:
ImprovemoldabilityVSAvoidmold weight
Core Design Contradiction:
Ease of manufactureVSWeight of moving object

Solution Approach 1:

The patent changes the material composition parameters by substituting heavy organic components (organic fibers, thermosetting resins) with lightweight inorganic alternatives (inorganic fibers, water glass binder). This parameter change maintains the molded article's formability and structural integrity while significantly reducing the overall weight.

Inventive Principle:
Principle #35Parameter changes

4Productivity

If sand reclamation process is used, then sand reuse is achieved, but waste generation occurs

Engineering Contradiction:
Improvesand reuseVSAvoidwaste generation
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The patent employs disposable inorganic binder materials that are applied in controlled amounts and intentionally consumed during the casting process. These binders decompose or vaporize completely, leaving no residual waste that requires reclamation processing, thereby eliminating the sand reclamation step and its associated dust waste.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 results in a lightweight, heat-resistant mold that reduces gas defects and improves surface smoothness of castings, ensuring high dimensional accuracy and reduced manufacturing costs.

Implementation Method 1

the molded article described still have room for improvements on gas defects in castings due to combustion gas from the organic matter of the molded article and surface smoothness of the castings

Methodology Applied
Scientific EffectThermal stability:

Implementation Method 2

a mold composition comprising inorganic particles, inorganic fibers, and layered clay minerals, with specific particle and fiber content ranges

Methodology Applied
Scientific EffectHeat resistance:

Implementation Method 3

a method involving mixing and heat-pressing to create a structure that minimizes gas defects and enhances surface smoothness and shape retention

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP3715010B1A mold, or a piece of a mold, a method for making a mold, or a piece of mold and a method for producing a casting
Publication Date: 2023.05.03 KAO CORP
  • EP3715010B1 patent drawingFigure 1

AI summary

A structure for manufacturing castings, containing an inorganic fiber, a layered clay mineral, and an inorganic particle other than the layered clay mineral and having an organic content of 5 mass% or lower or having a mass loss of 5 mass% or lower when heated at 1000°C for 30 minutes. The inorganic particle preferably contains one or more selected from obsidian, graphite, and mullite. The inorganic fiber preferably contains carbon fiber. The inorganic fiber preferably has an average length of 0.5 to 15 mm. The layered clay mineral preferably contains one or more selected from bentonite and montmorillonite.