Thermoplastic Microsphere Expansion Without Moisture

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Solution Overview

Problem

Existing methods for expanding thermally expandable thermoplastic microspheres often result in agglomerates and incompatibility due to moisture, leading to undesirable properties in final products, particularly in applications requiring uniform dispersion and stability.

Innovation Solution

An apparatus and method that utilize a heating zone capable of withstanding high pressure without direct fluid heat transfer, allowing partial expansion within the zone and full expansion in a lower-pressure area, combined with a distribution pipe for cooling and dispersion to prevent agglomeration, using a carrier liquid that is inert and water-free to maintain uniformity and prevent further expansion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If steam or moisture is introduced to heat and expand the thermally expandable microspheres, then the microspheres are expanded, but the moisture leads to incompatibility and agglomeration in the final product

Engineering Contradiction:
Improvemicrosphere expansion temperatureVSAvoidmoisture-induced agglomeration and incompatibility
Core Design Contradiction:
TemperatureVSObject-generated harmful factors

Solution Approach 1:

The patent introduces an inert gas (nitrogen or carbon dioxide) as an intermediary medium to heat the microspheres indirectly through a heat exchanger, preventing direct contact between moisture and the microspheres. This mediator transfers thermal energy without introducing harmful moisture, thus expanding the microspheres while maintaining their compatibility and preventing agglomeration.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates an inert atmosphere by using nitrogen or carbon dioxide gas in the expansion chamber and heat exchanger system. This inert environment prevents moisture from contaminating the microspheres during the heating and expansion process, eliminating the harmful effects of moisture-induced agglomeration and incompatibility in the final product.

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

2Productivity

If the microspheres are expanded rapidly, then productivity increases, but the microspheres stick together and form agglomerates

Engineering Contradiction:
Improvemicrosphere expansion rateVSAvoidagglomeration during rapid expansion
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The inert gas acts as a mediator between the heating system and the microspheres, allowing rapid heat transfer and expansion while preventing direct contact between microspheres and moisture. This enables high-speed expansion without agglomeration, as the inert gas cushion prevents the microspheres from sticking together during the rapid expansion process.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The inert atmosphere maintained throughout the expansion chamber and processing system prevents agglomeration by eliminating moisture-induced sticking. This allows the microspheres to be expanded rapidly with high productivity while remaining discrete and non-agglomerated, as the inert environment prevents the harmful sticking behavior.

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

3Volume of moving object

If the microspheres are expanded to large size, then the volume increases for better performance, but the transportation cost becomes prohibitive

Engineering Contradiction:
Improveexpanded microsphere volumeVSAvoidtransportation cost per unit volume
Core Design Contradiction:
Volume of moving objectVSQuantity of substance

Solution Approach 1:

The patent segments the expansion process into two distinct stages: first, transporting the compact thermally expandable microspheres in concentrated form; second, expanding them in-situ or near the application site to the final large size. This segmentation allows efficient low-volume transportation of the unexpanded microspheres while still achieving the desired large-volume expanded product at the destination, dramatically reducing transportation costs.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs the expansion action preliminarily planned and executes it at the optimal location (near the application site rather than at the manufacturing site). The microspheres are prepared in their compact unexpanded state for efficient transportation, then expanded in-situ when needed, combining the benefits of low transportation volume with the performance benefits of large expanded volume at the point of use.

Inventive Principle:
Principle #10Preliminary action

4Quantity of substance

If the microspheres are expanded close to or directly into the final application process, then transportation cost is reduced, but the microspheres may agglomerate in the apparatus

Engineering Contradiction:
Improvetransportation efficiencyVSAvoidagglomeration in expansion apparatus
Core Design Contradiction:
Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The inert atmosphere is maintained throughout the entire expansion apparatus and processing system, creating a moisture-free environment that prevents agglomeration. This allows the microspheres to be expanded in-situ close to the application process with high transportation efficiency, as the inert environment eliminates the sticking and agglomeration problems that would otherwise occur in the expansion apparatus.

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

Solution Approach 2:

The inert gas serves as a protective intermediary between the microspheres and the apparatus environment, preventing direct contact with moisture and contaminants in the expansion apparatus. This mediator enables in-situ expansion with high transportation efficiency while preventing agglomeration, as the inert gas cushion isolates the microspheres from harmful interactions with the apparatus.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution achieves uniformly expanded thermoplastic microspheres with improved dispersibility and stability, preventing agglomeration and ensuring consistent density distribution, suitable for a wide range of applications without the need for additional water or steam.

Implementation Method 1

a means for heating the slurry of thermally expandable thermoplastic microspheres in the heating zone to a temperature of at least 60°C without any direct contact of the slurry to any fluid heat transfer medium

Methodology Applied
Scientific EffectThermal heating: Heating

Implementation Method 2

a pump for feeding a slurry of thermally expandable thermoplastic microspheres into the heating zone. The pump is capable of generating a pressure of at least 4 bars in the heating zone

Methodology Applied
Scientific EffectPressure generation: Pressure Increase

Implementation Method 3

The outlet pipe of the apparatus is attached to a distribution pipe between an inlet and an outlet of the distribution pipe. The slurry is withdrawn into a zone with a lower pressure to fully expand the thermally expandable thermoplastic microspheres

Methodology Applied
Scientific EffectPressure drop expansion: Pressure Drop

Implementation Method 4

combined with a distribution pipe for cooling and dispersion to prevent agglomeration

Methodology Applied
Scientific EffectThermal cooling: Cooling

Data Source

PatentEP3230224B1Apparatus and method for expanding thermally expandable thermoplastic microspheres to expanded thermoplastic microspheres
Publication Date: 2018.10.17 CONSTRUCTION RESEARCH & TECHNOLOGY GMBH
  • EP3230224B1 patent drawingFigure 1
  • EP3230224B1 patent drawingFigure 2a~2b

AI summary

An apparatus and a method for expanding a slurry of thermally expandable thermoplastic microsphere is disclosed. The apparatus and method expand the slurry of thermally expandable thermoplastic microsphere without any direct contact to a fluid heat transfer medium. The apparatus and method utilise a distribution pipe attached to an outlet pipe.