Coalescing Agents for Gypsum Board Bubble Control

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Solution Overview

Problem

The gypsum board industry faces challenges in controlling the size and distribution of air bubbles in the gypsum core to reduce board weight while maintaining nail pull resistance and facer/gypsum core bond, as existing methods require multiple foaming agents and complex inventory management.

Innovation Solution

The use of coalescing agents with different cloud point temperatures, blended to achieve a lower cloud point than the mix temperature, allows for in-situ adjustment of the foam structure, reducing the need for multiple foaming agents and enabling flexible control of bubble structure during production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If multiple foaming agents are used to control bubble structure, then bubble size and distribution can be controlled, but inventory management complexity increases

Engineering Contradiction:

Improvebubble size and distribution controlVSAvoidinventory management complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent combines multiple foaming agents into a single blended composition that provides the desired bubble structure control. Instead of managing separate inventories of multiple foaming agents, the invention merges their functions into one composite additive package that achieves the same bubble control effects while simplifying inventory management.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The blended foaming agent composition serves multiple functions simultaneously - it controls bubble nucleation, regulates bubble growth, and maintains foam stability all through a single additive package. This multi-functional approach eliminates the need for separate specialized foaming agents for each function.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Manufacturing precision

If foam stability is increased to control bubble structure, then bubble distribution improves, but board weight reduction becomes difficult

Engineering Contradiction:

Improvebubble distribution controlVSAvoidboard weight

Core Design Contradiction:

Manufacturing precisionVSWeight of moving object

Solution Approach 1:

The invention uses foaming agents with controlled stability that allow the foam to be dynamic during different stages of board formation. The foam maintains stability during mixing and pouring to ensure good bubble distribution, but then allows controlled collapse during board formation to reduce final board weight while maintaining structural integrity.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The foaming agent composition is designed to provide periodic action - initial foam formation for bubble distribution, followed by controlled foam collapse for weight reduction. This time-dependent behavior allows the same foam structure to serve both purposes at different stages of the manufacturing process.

Inventive Principle:

Principle #19Periodic action

3Manufacturing precision

If process parameters are adjusted to optimize bubble structure, then board properties improve, but responsiveness to parameter changes is limited

Engineering Contradiction:

Improveboard propertiesVSAvoidresponsiveness to parameter changes

Core Design Contradiction:

Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The invention incorporates multiple foaming agents with different stability characteristics and response times into a single composition. This allows the foam system to respond differently to various process parameter changes - some agents respond to temperature changes, others to mixing intensity, and others to pH variations - providing enhanced adaptability and responsiveness to different manufacturing conditions.

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 approach effectively reduces board weight while maintaining desirable properties like nail pull resistance and paper/gypsum core bonding, with improved flexibility in reacting to process parameter changes, minimizing quality issues such as blisters and blows.

Implementation Method 1

first and second coalescing agents having different cloud point temperatures

Methodology Applied

Scientific EffectCloud point:

Implementation Method 2

controlling the size and distribution of the bubbles in the gypsum core

Methodology Applied

Scientific EffectCoalescence:

Implementation Method 3

the stucco rehydration reaction occurs, wherein the calcium sulfate hemihydrate reacts with water to form the gypsum crystal matrix

Methodology Applied

Scientific EffectRehydration reaction:

Implementation Method 4

During drying, the excess water (free water) is evaporated from the gypsum core

Methodology Applied

Scientific EffectEvaporation: Evaporation

Data Source

PatentUS9889579B2Gypsum wallboard and method of making same

Publication Date: 2018.02.13 GOLD BOND BUILDING PRODUCTS LLC

AI summary

Compositions for gypsum board are disclosed, comprising a mixture of a gypsum slurry and a pre-generated foam and a coalescing agent. The coalescing agent comprises one or more coalescing agents that are added to the composition singly, separately or in combination to change the size and distribution of the air bubbles in the foamed gypsum slurry. The resulting gypsum cores have increased nail pull resistance and an improved facer/gypsum core bond.