HRC Composition with Compression-Refined Pulp for Barrier Film Dewatering

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Solution Overview

Problem

Existing highly refined cellulose pulp (HRC) papers and films face challenges with high drainage resistance, brittleness, and poor mechanical properties, which hinder their production efficiency and performance in applications requiring gas barrier and transparency.

Innovation Solution

Incorporating compression refined cellulose pulp into the HRC composition improves mechanical properties while maintaining gas barrier and transparency by inducing fiber wall defects through compression refining, reducing the need for additional additives.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If highly refined cellulose pulp is used to form dense films, then gas barrier properties are improved, but drainage resistance increases

Engineering Contradiction:

Improvegas barrier propertiesVSAvoiddrainage resistance

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent applies compression refining to modify the physical and chemical parameters of cellulose fibers, creating fiber wall defects and changing fiber morphology. This parameter change allows the fibers to maintain dense film formation capability while improving drainage characteristics during web formation

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite fiber system by combining compression refined cellulose fibers with conventional cellulose fibers. This composite approach leverages the enhanced properties of compression refined fibers (improved drainage, reduced brittleness) while maintaining the barrier properties of the dense HRC film structure

Inventive Principle:

Principle #40Composite materials

2Strength

If compression refined cellulose pulp is added to improve mechanical properties, then strength and flexibility are improved, but gas barrier properties may deteriorate

Engineering Contradiction:

Improvemechanical propertiesVSAvoidgas barrier properties

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The patent applies compression refining selectively to portions of the cellulose fiber population rather than treating all fibers uniformly. This local quality approach ensures that only specific fibers acquire the enhanced mechanical properties needed for strength and flexibility, while the majority of fibers maintain the dense packing required for gas barrier performance

Inventive Principle:

Principle #3Local quality

3Productivity

If HRC suspension is applied on porous substrate for dewatering, then production efficiency is improved, but web defects increase due to high drainage resistance

Engineering Contradiction:

Improveproduction efficiencyVSAvoidweb defects

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent performs compression refining as a preliminary action before web formation and dewatering. This pre-treatment modifies the fiber characteristics in advance, preparing them to drain more effectively during the subsequent high-speed production process on the porous substrate, thereby preventing web defects

Inventive Principle:

Principle #10Preliminary action

4Manufacturing precision

If casting technology is used to form HRC films, then uniform thickness and smooth surface are achieved, but scalability is reduced

Engineering Contradiction:

Improvethickness uniformityVSAvoidscalability

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The patent replaces the casting process with a wire-forming and dewatering process that utilizes the modified drainage characteristics of compression refined fibers. This substitution enables the production of uniform, high-quality HRC films through a scalable mechanical dewatering process rather than a less scalable casting approach

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 addition of compression refined cellulose pulp enhances the mechanical strength and dewatering efficiency of HRC papers and films, allowing for faster production and improved handling without compromising gas barrier properties.

Implementation Method 1

compression refined cellulose pulp having a Schopper-Riegler number (SR) <50, as measured according to the standard ISO 5267-1, and a water retention value (WRV) >120%, as measured according to the standard ISO 23714

Methodology Applied

Scientific EffectCompression: Compression

Data Source

PatentUS20250250742A1Highly refined cellulose pulp composition with compression refined cellulose pulp

Publication Date: 2025.08.07 STORA ENSO OYJ

AI summary

The present invention relates to a highly refined cellulose pulp (HRC) composition for preparation of barrier papers or films, said composition comprising: 50-99 wt % HRC having a Schopper-Riegler number (SR)>70, as measured according to the standard ISO 5267-1, and 1-50 wt % of compression refined cellulose pulp having a Schopper-Riegler number (SR)<30, as measured according to the standard ISO 5267-1, and a water retention value (WRV)>120%, as measured according to the standard ISO 23714, based on the total dry weight of the HRC composition. The invention further relates to an HRC paper or film and a multilayer material comprising the HRC composition.