Sand Mold Riser Insulation for Casting Shrinkage

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Solution Overview

Problem

Current metal casting methods require separate exothermic and insulating sleeves for risers, which increase the work cycle and pose health risks due to uncontrolled materials, and involve expensive deburring operations, especially in constrained areas difficult to feed.

Innovation Solution

Applying an insulating or exothermic mixture directly to areas of the sand mold during its manufacturing that require greater insulation or heat supply, such as risers and internal areas, allowing the molten metal to remain in a liquid state longer and eliminating the need for separate sleeves.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate exothermic and insulating sleeves are placed around risers before casting, then the feed effect is improved and shrinkage cavities are reduced, but the work cycle is considerably increased

Engineering Contradiction:
Improvefeed effectVSAvoidwork cycle
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The invention combines the riser and the insulating/exothermic sleeve into a single integrated component. The sleeve material is incorporated directly into the riser structure during mold preparation, eliminating the need for separate placement operations. This integration maintains the thermal insulation and exothermic properties needed for effective feeding while reducing the number of discrete steps in the work cycle.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The insulating and exothermic properties are prepared in advance by incorporating the sleeve material into the riser structure during mold preparation, before the casting process begins. This preliminary integration ensures that the feed effect is optimized from the start without requiring additional time-consuming operations during the casting cycle.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If separate exothermic and insulating sleeves are placed around risers, then shrinkage compensation is improved, but the operation becomes more complex and materials are not controlled

Engineering Contradiction:
Improveshrinkage compensationVSAvoidoperation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention merges the riser structure with the insulating/exothermic sleeve into a single integrated component. This integration simplifies the operation by eliminating separate handling, placement, and positioning steps for the sleeve, while maintaining the shrinkage compensation function through the embedded thermal properties in the riser structure.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The riser structure itself provides the insulating and exothermic functions through integrated material incorporation, eliminating the need for separate sleeve components. This self-service approach reduces operational complexity while ensuring controlled material composition for reliable shrinkage compensation.

Inventive Principle:
Principle #25Self-service

3Manufacturing precision

If padding is produced in constrained areas to assure complete filling, then difficult-to-feed areas are properly filled, but expensive deburring operations are required

Engineering Contradiction:
Improvecomplete fillingVSAvoiddeburring cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The invention applies insulating and exothermic properties locally in constrained and difficult-to-feed areas of the mold cavity. By targeting these specific regions with enhanced thermal retention, the molten metal remains liquid longer in these areas, ensuring complete filling without requiring excessive padding material that would subsequently require expensive deburring operations.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention changes the thermal parameters (insulation and exothermic properties) in specific constrained areas of the mold to extend the liquid state duration of the metal locally. This parameter modification enables complete filling of difficult-to-reach areas without the need for volumetric padding, thereby eliminating subsequent deburring costs.

Inventive Principle:
Principle #35Parameter changes

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 method reduces the need for separate sleeves, minimizes shrinkage cavities, and ensures complete filling of difficult-to-reach areas while using safer, controlled materials that comply with environmental regulations.

Implementation Method 1

the insulating or exothermic mixture delays the solidification of the molten metal cast in step e) in the areas in which the mentioned mixture has been arranged

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

areas of the mold which require a greater insulation or heat supply by exothermic reaction

Methodology Applied
Scientific EffectExothermic reaction: Exothermic Reaction

Data Source

PatentEP2581149B1Method for producing a metal part
Publication Date: 2018.01.03 ASK CHEM ESPANA
  • EP2581149B1 patent drawingFigure 1~2
  • EP2581149B1 patent drawingFigure 3~4
  • EP2581149B1 patent drawingFigure 5

AI summary

The invention relates to methods of casting metal parts in sand molds, with the particularity that it is not necessary to use sleeves surrounding the feed risers which are arranged outside the part to offset the shrinkage occurring during the solidification of the molten metals. The operations of placing the sleeves which must be arranged around the risers are eliminated with the method object of the invention, the actual sleeves being made when the sand mold is produced.