Surface-Enhanced Pulp Fibers Through Length-Preserving Refining

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Solution Overview

Problem

Conventional refining processes of pulp fibers result in significant reductions in fiber length and generate undesirable amounts of fines, affecting the properties and performance of end products such as paper and biofiber composites.

Innovation Solution

A method for producing surface enhanced pulp fibers involves recirculating fibers through mechanical refiners multiple times using fine-grooved plates and controlled refining conditions to maintain fiber length while increasing surface area, minimizing fines generation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of moving object

If conventional refining processes are used to increase surface area, then surface area is improved, but fiber length is reduced and fines are generated

Engineering Contradiction:
Improvesurface areaVSAvoidfiber length
Core Design Contradiction:
Area of moving objectVSLength of moving object

Solution Approach 1:

The patent applies parameter changes by modifying the refiner plate geometry (bar width, groove width, groove depth) and refining conditions (specific edge load, recirculation ratio) to achieve surface area enhancement while preserving fiber length. The use of fine-grooved plates with specific dimensional parameters enables controlled fibrillation that increases surface area without the excessive fiber shortening seen in conventional refining.

Inventive Principle:
Principle #35Parameter changes

2Area of moving object

If conventional refining processes are used to increase surface area, then surface area is improved, but fines generation increases

Engineering Contradiction:
Improvesurface areaVSAvoidfines generation
Core Design Contradiction:
Area of moving objectVSObject-generated harmful factors

Solution Approach 1:

The patent applies local quality by creating localized fibrillation zones on the refiner plates with specific groove patterns and dimensions. The fine-grooved plates concentrate the refining action in specific local areas, enabling surface area enhancement through controlled local fibrillation rather than global fiber breakdown, thereby reducing overall fines generation.

Inventive Principle:
Principle #3Local quality

3Area of moving object

If multiple passes through refiner are used to increase surface area, then surface area is improved, but fiber length is reduced

Engineering Contradiction:
Improvesurface areaVSAvoidfiber length
Core Design Contradiction:
Area of moving objectVSLength of moving object

Solution Approach 1:

The patent applies continuity of useful action through recirculation, where fibers that have undergone initial fibrillation are returned to the refiner for additional passes. This continuous process allows progressive surface area enhancement while the controlled refiner parameters prevent excessive fiber shortening that would occur with multiple sequential passes through conventional refiners.

Inventive Principle:
Principle #20Continuity of useful action

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 method preserves fiber length and significantly enhances surface area without generating excessive fines, improving properties like binding, water retention, and strength in papermaking applications.

Implementation Method 1

A method for producing surface enhanced pulp fibers comprises introducing unrefined pulp fibers in a mechanical refiner

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP3287564B2Surface enhanced pulp fibers, methods of making surface enhanced pulp fibers, products incorporating surface enhanced pulp fibers, and methods of making products incorporating surface enhanced pulp fibers
Publication Date: 2025.10.15 DOMTAR PAPER COMPANY LLC(US)
  • EP3287564B2 patent drawingFigure 1
  • EP3287564B2 patent drawingFigure 2
  • EP3287564B2 patent drawing

AI summary

Various embodiments of the present invention relate to surface enhanced pulp fibers, various products incorporating surface enhanced pulp fibers, and methods and systems for producing surface enhanced pulp fibers. Various embodiments of surface enhanced pulp fibers have significantly increased surface areas compared to conventional refined fibers while advantageously minimizing reductions in length following refinement. The surface enhanced pulp fibers can be incorporated into a number of products that might benefit from such properties including, for example, paper products, paperboard products, fiber cement boards, fiber reinforced plastics, fluff pulps, hydrogels, cellulose acetate products, and carboxymethyl cellulose products. In some embodiments, a plurality of surface enhanced pulp fibers have a length weighted average fiber length of at least about 0.3 millimeters and an average hydrodynamic specific surface area of at least about 10 square meters per gram, wherein the number of surface enhanced pulp fibers is at least 12,000 fibers/milligram on an oven-dry basis.