Binder-Free Zirconia Granulate via Build-Up Agglomeration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional processes for preparing zirconia ceramic products face challenges in achieving optimal processing properties, such as flowability and the need for debinding steps, which increase processing time and material loss.
Innovation Solution
A process involving the agglomeration of zirconia powder through build-up granulation to create a granulate that is flowable and can be processed without binders, allowing for direct sintering and reduced material loss, using a suspension with minimal organic components and agglomerating without the addition or removal of liquids.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If conventional granulation processes are used with binders, then the cohesion of powder particles is improved, but the processing time increases due to required debinding steps and material loss occurs
Solution Approach 1:
The invention extracts and eliminates the binder component from the granulation process. By using build-up granulation without organic binders, the patent removes the need for debinding steps, directly resolving the contradiction between particle cohesion and processing time.
Solution Approach 2:
The granulation process serves itself by using the powder particles' own properties and the granulation mechanism to achieve cohesion without external binders. The build-up granulation creates self-supporting granules that maintain cohesion through the granulation structure itself.
2Productivity
If build-up granulation is used without binders, then processing time is reduced and material loss is minimized, but the challenge of achieving adequate particle cohesion arises
Solution Approach 1:
The invention performs preliminary classification of powder particles by size before granulation. This preliminary action ensures that particles of appropriate sizes are available for efficient build-up granulation, enabling fast processing while maintaining adequate cohesion through proper particle size matching.
Solution Approach 2:
The invention changes the particle size distribution parameter by classifying powder into different size fractions. This parameter change optimizes the granulation process by ensuring a suitable mix of particle sizes that promotes both rapid granule formation and adequate structural cohesion.
3Ease of operation
If flow aids such as fumed silica are added to improve flowability, then the flow properties are enhanced, but the process complexity and cost increase
Solution Approach 1:
The invention extracts and eliminates flow aids from the process by achieving adequate flowability through the build-up granulation process itself. The granulated structure naturally provides improved flow properties without requiring additional chemical additives.
Solution Approach 2:
The invention replaces expensive flow aids with a simpler, more economical approach. The build-up granulation process itself serves as the flowability enhancement mechanism, eliminating the need for costly fumed silica or other flow aid additives.
4Ease of manufacture
If conventional sintering processes are used with binder-containing granulates, then the shaping process is simplified, but the overall manufacturing cost increases due to debinding requirements
Solution Approach 1:
The invention extracts binders from the granulate composition, eliminating the debinding step and associated material loss. The direct sintering of binder-free granules recovered material that would otherwise be lost during debinding operations.
Solution Approach 2:
The invention creates a continuous process by eliminating the debinding step between granulation and sintering. The useful action of transforming the granulate to the final product continues uninterrupted, improving both efficiency and material utilization.
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 resulting zirconia granulate exhibits excellent pressability, enabling automated processing, omitting the debinding step, and using inexpensive starting materials, thus reducing overall processing duration and material loss while maintaining mechanical and optical properties suitable for dental restorations.
Implementation Method 1
a zirconia powder is agglomerated by build-up granulation to give the granulate
Implementation Method 2
the starting material should be flowable and should not contain any undesirable compounds which have to be removed again in the course of the manufacture of zirconia products
Data Source
AI summary
The invention relates to a process for the preparation of a zirconia granulate from a zirconia powder and to the use of the granulate for the preparation of dental blanks and dental restorations.