Ceramic Feedstock Viscosity Control via Temperature-Sensitive Gelling

Solution Overview

Problem

Low pressure injection molding (LPIM) faces challenges in preparing highly concentrated ceramic slurries and providing user-friendly feedstocks due to the need for high solids concentration and viscosity suitable for the process.

Innovation Solution

A ceramic formulation comprising ceramic precursors, a temperature-sensitive gelling agent, and solvent with a solids concentration of at least 50 vol.%, and a method to prepare a dried or partially dried ceramic feedstock with up to 15 wt.% residual solvent content, allowing for viscosity adjustment suitable for LPIM by mixing with additional solvent above the gel point of the gelling agent.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If highly concentrated ceramic slurries are prepared for LPIM, then solids concentration is improved, but viscosity control and processing ease deteriorate

Engineering Contradiction:

Improvesolids concentrationVSAvoidviscosity control

Core Design Contradiction:

Quantity of substanceVSEase of operation

Solution Approach 1:

The patent employs temperature-sensitive gelling agents that dynamically change the slurry's viscosity based on temperature. At processing temperature, the slurry maintains low viscosity for easy injection, while upon cooling, it gels to provide structural support. This dynamic viscosity control enables high solids concentration without compromising processability.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The invention changes the temperature parameter to control the physical state of the slurry. By maintaining the slurry above the gel point during injection molding, low viscosity is achieved. After molding, cooling below the gel point transforms the slurry into a gel state, enabling high solids concentration to be maintained without sacrificing ease of operation.

Inventive Principle:

Principle #35Parameter changes

2Strength

If conventional ceramic feedstocks are used, then manufacturing simplicity is maintained, but mechanical strength and green body stability deteriorate

Engineering Contradiction:

Improvemechanical strengthVSAvoidfeedstock preparation complexity

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The patent utilizes phase transition of temperature-sensitive gelling agents to transform the feedstock from a liquid slurry to a gel state. This phase transition occurs upon cooling below the gel point, providing mechanical strength and structural stability to the green body without requiring complex preparation equipment or procedures.

Inventive Principle:

Principle #36Phase transitions

Solution Approach 2:

The invention creates a composite feedstock system combining ceramic particles with temperature-sensitive gelling agents. This composite structure provides both the mechanical strength needed for green body stability and the simplicity of conventional feedstock preparation, as the gelling agent integrates seamlessly into the existing slurry formulation process.

Inventive Principle:

Principle #40Composite materials

3Ease of operation

If slurry viscosity is reduced for easy injection, then ease of operation is improved, but solids concentration deteriorates

Engineering Contradiction:

Improveinjection molding easeVSAvoidsolids concentration

Core Design Contradiction:

Ease of operationVSQuantity of substance

Solution Approach 1:

The patent employs temperature-sensitive gelling agents that dynamically change the slurry's viscosity based on temperature. At processing temperature, the slurry maintains low viscosity for easy injection, while upon cooling, it gels to provide structural support. This dynamic viscosity control enables high solids concentration without compromising processability.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The invention changes the temperature parameter to control the physical state of the slurry. By maintaining the slurry above the gel point during injection molding, low viscosity is achieved. After molding, cooling below the gel point transforms the slurry into a gel state, enabling high solids concentration to be maintained without sacrificing ease of operation.

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

Enables the production of ceramic articles with enhanced mechanical strength and processing convenience through the creation of a ceramic feedstock with controlled viscosity and solvent content, facilitating the formation of complex shapes and high-solid-content ceramic formulations for LPIM.

Implementation Method 1

temperature sensitive gelling agent, for example, a polysaccharide... at a temperature greater than the gel point of the gelling agent

Methodology Applied

Scientific EffectGelation: Gel

Data Source

PatentUS20240360038A1Ceramic compositions

Publication Date: 2024.10.31 IMERTECH SAS

AI summary

A dried or at least partially dried ceramic feedstock, a method of preparing a dried or at least partially dried ceramic feedstock having a residual solvent content of up to about 5 wt. %, ceramic formulations comprising one or more ceramic precursors, temperature sensitive gelling agent, solvent, and having a viscosity suitable for low pressure injection molding, methods for preparing said ceramic formulations, a method of forming a ceramic article from said ceramic formulations, and a ceramic article obtainable therefrom.