Microfibrillated Cellulose Pulp Sheets for Mechanical Property Retention

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Solution Overview

Problem

Existing methods fail to maintain the mechanical properties of microfibrillated cellulose (MFC) sheets after drying and re-dispersion in an aqueous medium, limiting their use in papermaking applications.

Innovation Solution

Manufacturing sheets comprising microfibrillated cellulose and pulp blends with enhanced mechanical properties by adding MFC to pulp before drying, and forming them into sheets that maintain these properties even after drying and re-dispersion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If MFC sheets are dried for commercial transport and storage, then the sheets become stable and manageable, but the mechanical properties of the MFC are substantially degraded

Engineering Contradiction:

Improvesheet stabilityVSAvoidmechanical properties

Core Design Contradiction:

Stability of the object's compositionVSStrength

Solution Approach 1:

The patent uses an intermediary substance (such as a binder or protective coating) that is applied to the MFC sheet during the drying process. This intermediary protects the MFC fibrils from damage during drying and storage, allowing the sheet to maintain its mechanical properties while still achieving the stability needed for commercial handling and transport.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Strength

If MFC is added to pulp to enhance mechanical properties, then tensile strength and opacity improve, but the complexity of the manufacturing process increases

Engineering Contradiction:

Improvetensile strengthVSAvoidmanufacturing process complexity

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The patent merges the MFC addition step with the existing pulp processing workflow. Instead of treating MFC as a separate, complex addition requiring specialized equipment, the process integrates MFC incorporation into standard pulp mixing and sheet formation operations already present in papermaking facilities, thereby enhancing tensile strength without significantly increasing manufacturing complexity.

Inventive Principle:

Principle #5Merging (Combining)

3Adaptability or versatility

If MFC sheets are re-dispersed in aqueous medium after drying, then they can be re-used in papermaking, but the mechanical properties are lost

Engineering Contradiction:

Improvere-dispersabilityVSAvoidmechanical properties

Core Design Contradiction:

Adaptability or versatilityVSStrength

Solution Approach 1:

The patent applies preliminary protective measures during the drying process that preserve the MFC's ability to be re-dispersed while maintaining its mechanical properties. This may involve using specific drying conditions, protective coatings, or binder systems that prevent irreversible damage to the MFC structure, allowing the sheet to be re-dispersed in aqueous medium and retain its enhanced mechanical properties for subsequent papermaking applications.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS12385185B2Microfibrillated cellulose containing pulp sheets with improved mechanical properties

Publication Date: 2025.08.12 FIBERLEAN TECH LTD

AI summary

A method of manufacturing a partially-dried sheet comprising, consisting essentially of, or consisting of, microfibrillated cellulose suitable for use as a binder, or a dried sheet comprising, consisting essentially of, or consisting of, a blend of microfibrillated cellulose and a pulp suitable for use as a pulp source, wherein said sheet may be redispersed with a high shear disperser, mixer or refiner operated at energy inputs of about 10 kWh/t to about 2,000 kWh/t, wherein the sheet upon re-dispersion in a aqueous medium maintains, or is not substantially degraded in, tensile index, compared to the dried sheet prior to drying and re-dispersion.