CH-Acidic Sizing Composition for Metal Casting Mold Cores
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current water-based sizing compositions for metal casting molds and cores suffer from reduced strength and increased moisture sensitivity, leading to potential breakage under metallostatic pressure and high humidity conditions, and they also contribute to formaldehyde emissions during the drying process.
Innovation Solution
A water-based sizing composition incorporating CH-acidic compounds with a structural element of —C(═O)—CH2—C(═O)— is used, which significantly enhances the moisture resistance and storage stability of coated cores and molds, allowing for thinner designs and reduced binder usage, while also minimizing formaldehyde emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If water-based sizing compositions are used to reduce environmental impact and improve safety, then health and environmental safety are improved, but the strength and moisture resistance of cores decrease significantly
Solution Approach 1:
The patent modifies the chemical composition parameters of water-based sizing compositions by incorporating specific binders (sodium silicate, potassium silicate, water glass) and adhesion promoters (silanes, esters, anhydrides) to achieve both low formaldehyde emissions and high core strength. This parameter optimization resolves the contradiction between environmental safety and mechanical strength.
Solution Approach 2:
The invention uses composite binder systems combining multiple components (water glass, silanes, esters, anhydrides) to create a sizing composition that simultaneously provides moisture resistance, strength, and low formaldehyde emissions. The composite nature of the binder system allows synergistic effects that overcome the limitations of single-component water-based sizes.
2Object-affected harmful factors
If water-based sizing compositions are used to improve safety and reduce emissions, then health and environmental safety are improved, but moisture resistance of cores decreases
Solution Approach 1:
The patent adjusts the chemical parameters of the sizing composition by selecting specific water glass moduli, silane types, and ester/anhydride combinations to optimize moisture resistance while maintaining low formaldehyde emissions. The modified chemical structure provides both environmental safety and moisture stability.
Solution Approach 2:
The invention introduces intermediary substances such as silanes and esters that act as coupling agents between the water-based size and the core material. These intermediaries enhance moisture resistance by creating stronger interfacial bonds without compromising the water-based formulation's environmental benefits.
3Strength
If core dimensions are increased to compensate for reduced strength, then core strength is improved, but designing and construction freedom of components is limited
Solution Approach 1:
By fundamentally changing the chemical composition parameters of the sizing composition to include optimized binder systems, the patent achieves high core strength with reduced dimensions. This allows designers to create thinner, more complex core geometries without sacrificing structural integrity, thereby maintaining designing freedom.
4Strength
If more binder is used to increase core strength, then core strength is improved, but formaldehyde emissions increase
Solution Approach 1:
The patent changes the binder composition parameters by using water glass-based binders with controlled moduli and combining them with low-formaldehyde additives. This parameter optimization achieves high core strength while minimizing formaldehyde emissions, breaking the direct proportionality between binder quantity and emissions.
Solution Approach 2:
The invention employs binders that provide sufficient strength for the core's functional life but decompose cleanly with minimal formaldehyde emissions during the brief high-temperature exposure of casting. This approach accepts temporary binder consumption in exchange for reduced harmful emissions.
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 CH-acidic compounds improve the moisture resistance and mechanical strength of coated cores and molds, enabling thinner designs and reduced binder usage, and effectively decrease formaldehyde emissions during the casting process.
Implementation Method 1
A water-based sizing composition for molds or cores for metal casting, containing at least one CH-acidic compound having the structural element: —C(═O)—CH2—C(═O)—
Implementation Method 2
the strengths of the cores treated with the water-based sizing composition decrease significantly... the at least partially cured cores and molds produced in this manner are provided, at least on patches, with the sizing composition according to the invention in the form of a film or a coating
Implementation Method 3
Quartz sand expands with an increase in temperature due to heat expansion until at 573° C. a change of form takes place from alpha- to beta-quartz, also known as quartz inversion, which brings with it a sudden increase in volume
Implementation Method 4
The high temperatures of the liquid metal, in particular, for example, with cast iron (casting temperatures between about 1300° C. and 1500° C.) or cast steel (casting temperatures between about 1500° C. and 1700° C.)... lead to decomposition of the organic binder and heat the core or respectively the mold
Implementation Method 5
The high temperatures of the liquid metal... lead to decomposition of the organic binder
Data Source
AI summary
The subject matter of the invention are sizing compositions containing an aqueous carrier liquid, refractory base materials and CH-acidic compounds, as well as their use for casting molds, as well as casting molds coated with the sizing composition.