Lost Core Production Using Alkali Silicate Binder and Hot Air Curing
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Solution Overview
Problem
Current core production processes for high-value, geometrically complex lost cores require harmful binders and catalysts or expensive, energy-intensive metallic core boxes, posing environmental and health concerns.
Innovation Solution
A method using an alkali silicate or water glass binder with natural and synthetic additives, mixed with a basic moulding material, is moulded in an unheated core box and hardened with hot air, eliminating the need for active heating and allowing the use of environmentally friendly binder systems and core boxes made from wood, plastic, or metal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If harmful binders and catalysts are used in core production, then the production of complex lost cores is enabled, but environmental and health concerns arise
Solution Approach 1:
The patent changes the chemical composition parameters of the binder system by replacing harmful organic binders and catalysts with an inorganic binder based on alkali silicate or water glass combined with aluminum phosphate. This parameter change eliminates harmful emissions while maintaining the binding functionality required for producing complex lost cores
Solution Approach 2:
The patent employs disposable core boxes made from wood, plastic, or metal that do not require active heating. These inexpensive, single-use molds eliminate the need for expensive, energy-intensive metallic core boxes while enabling the use of environmentally friendly binder systems
2Ease of manufacture
If expensive, energy-intensive metallic core boxes with active heating are used, then core production is enabled, but energy consumption increases
Solution Approach 1:
The patent replaces expensive, energy-intensive metallic core boxes with inexpensive disposable core boxes made from wood, plastic, or metal. These simplified molds eliminate the need for active heating systems while maintaining core production capability
Solution Approach 2:
The patent extracts and removes the active heating function from the core box system. By separating the heating requirement from the mold structure, the invention allows use of simple, unheated disposable molds while the binder system provides sufficient strength without thermal processing
3Strength
If high primary strength binders are used, then stable lost cores for complex shapes are produced, but removal after casting becomes difficult
Solution Approach 1:
The patent changes the chemical composition parameters of the binder to create a dual-characteristic system. The aluminum phosphate-modified alkali silicate binder provides high primary strength for complex shapes while incorporating specific chemical components that reduce secondary strength after casting, enabling easy removal
Solution Approach 2:
The binder exhibits time-dependent strength characteristics: high primary strength immediately after molding to maintain complex shapes, followed by gradual strength reduction over time to facilitate easy removal after casting. This periodic strength variation is achieved through the chemical composition of the aluminum phosphate-modified binder system
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 enables the production of stable lost cores with high primary strength for complex shapes, while reducing energy consumption and environmental impact, and allows for easy removal after casting with low secondary strength.
Implementation Method 1
subsequent solidification of the moulding mixture, which is still loosely packed, can be carried out by various methods, for example by the passage of a hardening gas, for example carbon dioxide
Implementation Method 2
Hardening in this case is carried out by means of a stepwise dehydration of the core moulding material using die temperatures between 150° C. and 250° C. as well as subsequently flushing with hot air in the same temperature range
Data Source
AI summary
The invention relates to a method for producing lost cores or molded parts for the production of cast parts, in which a basic molding material is mixed with an alkali silicate or water glass binder and a lost core or a molded part for the production of cast parts is formed using a core shooter in a core box, wherein the alkali silicate or water glass binder contains an alkali silicate or water glass solution having a modulus of 1.5 to 3.5 and natural and/or synthetic additives in a proportion of 0.1 to 25% by weight measured with respect to the total amount of binder, with a particle size of less than 5 μm and the natural and/or synthetic additives are at least aluminum silicate, magnesium silicate and sodium aluminum silicate, each having a proportion of 1 to 5% by weight measured with respect to the total amount of binder. The lost core or the other molded part is formed in an unheated core box, and the lost core thus formed or the molded part is cured using hot air.