Water-Soluble Pouch Stability with Magnesium Salt

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Solution Overview

Problem

Water-soluble pouches made from polyvinyl alcohol and carboxylic acid co-polymers exhibit poor compatibility and solubility when containing dissolved ionic components like carboxylates and phosphonates, leading to solubility loss and residue formation on fabrics during washing, especially after prolonged storage.

Innovation Solution

A water-soluble pouch containing a liquid composition with 5-15% water and a magnesium salt, processed using a vacuum-formed horizontal form-fill-seal process, which enhances the stability and solubility of ionic components and prevents lactone formation in the film.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If water-soluble film comprising co-polymer of vinyl alcohol and carboxylic acid is used to package liquid detergent with dissolved ionic components, then the pouch provides convenient packaging and unit dose delivery, but the pouch exhibits poor compatibility and solubility loss especially after prolonged storage

Engineering Contradiction:
Improvepouch solubilityVSAvoidfilm composition stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The invention extracts and removes the harmful ionic components (carboxylates and phosphonates) from the liquid detergent composition, or uses alternative non-ionic builders that do not cause lactone formation, thereby eliminating the root cause of solubility loss while maintaining the pouch's water-soluble properties

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the chemical composition parameters of the liquid detergent by selecting specific ionic components or their concentrations that are compatible with the water-soluble film, or by modifying the film's chemical structure to resist lactone formation, thereby resolving the incompatibility issue

Inventive Principle:
Principle #35Parameter changes

2Reliability

If dissolved ionic components (carboxylates, phosphonates) are included in the liquid detergent composition, then the detergent provides effective building and chelating functions, but the water-soluble pouch exhibits solubility loss and forms polymeric residues on fabric

Engineering Contradiction:
Improvedetergent functionalityVSAvoidpolymer residue on fabric
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The invention converts the harmful interaction between ionic components and the film into a beneficial outcome by using controlled lactone formation or alternative film compositions that actually enhance the detergent's performance while preventing residue formation on fabrics

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The invention introduces intermediary substances or modifies the film structure to mediate between the ionic components and the film matrix, preventing direct harmful interactions that lead to insolubilization while allowing the ionic components to perform their building and chelating functions

Inventive Principle:
Principle #24Intermediary (Mediator)

3Stability of the object's composition

If additional water is added to the detergent composition to dissolve ionic components, then the ionic components are stably dissolved, but the solubility of the water-soluble pouch is further reduced

Engineering Contradiction:
Improveionic component dissolutionVSAvoidpouch solubility
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The invention optimizes the water content parameter and the concentration of ionic components to achieve a balance where sufficient dissolution occurs without excessive water that would promote lactone formation and reduce pouch solubility

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

The solution ensures improved dissolution and disintegration profiles of the pouches even after prolonged storage, maintaining the functionality of ionic components with reduced amounts and preventing polymer residue on fabrics, while being manufactured using commercially available films without modifications.

Implementation Method 1

the insolubilization phenomenon is due to the undesirable formation of lactone rings in and/or on the water-soluble film

Methodology Applied
Scientific EffectLactone formation: Chemical Bonding

Implementation Method 2

The film enveloping the liquid product, which forms the wall of the pouch, is soluble in water. A particularly suitable water-soluble film for this purpose is made from polyvinyl alcohol

Methodology Applied
Scientific EffectHydrolysis: Hydrolysis

Data Source

PatentEP1854869B2Water-soluble, liquid-containing pouch
Publication Date: 2014.12.03 PROCTER & GAMBLE CO

AI summary

A water-soluble pouch containing a liquid composition wherein the water-soluble pouch is made from a film comprising a co-polymer of vinyl alcohol and a carboxylic acid, wherein the liquid composition contained within said pouch comprises at least one dissolved ionic component selected from the group consisting of carboxylates, phosphonates, and mixtures thereof, and from 5% to 15 % by weight of the liquid composition of water, and wherein said pouch is processed using a vacuum formed, horizontal form-fill-seal process.