Solvent-Free Thermoplastic Dispersion Mixing via Segmented Vessel
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing thermoplastic elastomeric polymer dispersions often require solvents and struggle to achieve small particle sizes and high solids content with efficient storage stability and low pH values.
Innovation Solution
A solvent-free process using a reaction vessel with a primary and secondary volume, where stirrers handle high viscosities, and a specific temperature and recycling ratio are maintained to produce dispersions with particle sizes below 20 μm and high solids content, ensuring stability and low pH.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional solvent-free emulsification methods are used, then the process is simple, but the particle size is large and storage stability is poor
Solution Approach 1:
The mixing system is segmented into two distinct volumes: a first volume for initial emulsification and a second volume for secondary homogenization. This segmentation allows each stage to perform its specific function optimally, resulting in reduced particle sizes and improved storage stability without excessive complexity
Solution Approach 2:
A secondary stirrer acts as an intermediary element between the first volume and the final dispersion product. This intermediary component performs additional homogenization of the emulsion, ensuring narrow particle size distribution and excellent storage stability
2Quantity of substance
If high solids content dispersions are produced, then material efficiency improves, but viscosity increases making handling difficult
Solution Approach 1:
The process is divided into two stages: first volume for initial emulsification and second volume for final homogenization. This segmentation enables the production of high solids content dispersions while maintaining manageable viscosity through progressive mixing
Solution Approach 2:
The secondary stirrer continuously homogenizes the emulsion in the second volume, maintaining optimal mixing action throughout the process. This continuous useful action ensures high solids content is achieved while the dispersion remains handleable
3Reliability
If neutralization is performed to improve stability, then storage stability improves, but pH increases which may be undesirable
Solution Approach 1:
Partial neutralization is performed rather than complete neutralization. This partial action provides sufficient storage stability while maintaining lower pH levels that are more desirable for certain applications
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 process efficiently produces thermoplastic elastomeric polymer dispersions with narrow particle size distribution, high solids content, and excellent storage stability, eliminating the need for solvents and achieving low pH values.
Implementation Method 1
a first stirrer is located and operative in said first volume
Implementation Method 2
a secondary stirrer is located and operative in said secondary volume... operating the secondary stirrer in the second volume at a speed of above 1000 rpm
Implementation Method 3
recycling the reaction product through said secondary stirrer... maintaining a recycle ratio of at least three between the first and the second volume
Data Source
AI summary
Disclosed is a method for the production of thermoplastic polymer dispersions, using a reaction vessel with a first volume and a secondary volume, wherein a first stirrer is located and operative in said first volume and a secondary stirrer is located and operative in said secondary volume, wherein the first volume is at least 20 times larger than the secondary volume, wherein the stirrers in both volumes are able to handle viscosities above of or equal to 1000 mpas, including the steps of a.) loading the first volume of the vessel with an initial amount of polymer and optionally water and optionally alkaline; b.) heating the vessel externally to a target process temperature in the range of 80-300° C.; c.) operating the first stirrer in the first volume for at least half an hour at a speed of in the range of 10-100 rpm; d.) addition of water and optionally alkaline to the first volume; e.) connection of the secondary volume to the first volume and operating the secondary stirrer in the secondary volume at a speed of above 1000 rpm and recycling the reaction product through said secondary stirrer while keeping the operating temperature essentially constant during a timespan in excess of the recycle ratio3 of the primary and the secondary mixer to form the dispersion. Furthermore disclosed is a dispersion as obtainable using such a method and a reaction vessel for carrying out such a method.