Dry-Formed Cellulose Moulding with Low-Moisture Single Pressing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing cellulose product manufacturing methods, particularly wet-forming techniques, require significant water usage, are energy-intensive, and struggle with precise control over mechanical properties and dimensional stability.

Innovation Solution

A dry-forming method using an air-formed cellulose blank structure with 4-15 wt% moisture, subjected to 1-100 MPa pressure and 100-200°C temperature in a single pressing operation, forming hydrogen bonds efficiently to produce rigid and dimensionally stable products.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If wet-forming techniques are used to produce cellulose products, then the products can be formed from liquid or semi-liquid pulp suspension, but the process requires high amounts of water and energy-consuming drying

Engineering Contradiction:
Improveforming processVSAvoiddrying energy
Core Design Contradiction:
Ease of manufactureVSUse of energy by moving object

Solution Approach 1:

The invention changes the moisture content parameter of the cellulose blank structure from high (wet-forming) to low (4-15 wt%), transforming the process from wet-forming to dry-forming. This parameter change eliminates the need for energy-consuming drying operations while maintaining formability through controlled moisture levels that enable hydrogen bond formation during pressing.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention extracts water from the cellulose blank structure to reduce moisture content to 4-15 wt% before forming. By removing excess water that would otherwise require energy-intensive drying, the process achieves water-efficient and energy-efficient production while maintaining the necessary moisture for hydrogen bond formation during the forming operation.

Inventive Principle:
Principle #2Taking out (Extraction)

2Ease of manufacture

If air-formed cellulose blank structure with high humidity (up to 45 wt% water) is used in dry-forming, then the cellulose product can be formed without wet-forming techniques, but the forming process becomes energy demanding and time consuming due to water removal

Engineering Contradiction:
Improvedry-forming processVSAvoidforming time
Core Design Contradiction:
Ease of manufactureVSLoss of time

Solution Approach 1:

The invention optimizes the moisture content parameter to a specific range of 4-15 wt%, which is lower than conventional air-formed blanks (up to 45 wt%). This parameter optimization enables single pressing operation forming without the need for prolonged water removal, significantly reducing forming time while maintaining the moisture necessary for hydrogen bond formation and product rigidity.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If wet-formed cellulose products are produced, then the products can be manufactured from pulp suspension, but the mechanical strength, flexibility, and chemical properties are limited

Engineering Contradiction:
Improvemanufacturing processVSAvoidmechanical strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The invention changes the moisture content parameter to 4-15 wt% and applies pressing and heating during forming, which promotes hydrogen bond formation between cellulose fibres. This parameter change and process modification enhance mechanical strength, flexibility, and chemical properties compared to wet-formed products, while maintaining manufacturing efficiency.

Inventive Principle:
Principle #35Parameter changes

4Ease of manufacture

If conventional dry-forming with high moisture content (up to 45 wt%) is used, then the cellulose product can be formed in a dry-forming mould system, but the process requires multiple pressing operations and extended curing time

Engineering Contradiction:
Improvedry-forming processVSAvoidproduction efficiency
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The invention optimizes moisture content to 4-15 wt%, which enables single pressing operation forming and reduces curing time. This parameter optimization directly improves productivity by eliminating the need for multiple pressing operations and extended curing periods required when using higher moisture content blanks (up to 45 wt%), while maintaining product quality through controlled hydrogen bond formation.

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 method reduces water consumption, minimizes curing time, and achieves high-quality cellulose products with improved mechanical properties and dimensional stability using minimal energy.

Implementation Method 1

forming hydrogen bonds efficiently to produce rigid and dimensionally stable products

Methodology Applied
Scientific EffectHydrogen bonding: Chemical Bonding

Implementation Method 2

heated to a forming temperature in the range of 100-200 °C, preferably in the range of 120-170 °C

Methodology Applied
Scientific EffectThermal heating: Heating

Implementation Method 3

pressed with a forming pressure in the range of 1-100 MPa, preferably in the range of 8-20 MPa

Methodology Applied
Scientific EffectMechanical compression: Compression

Data Source

PatentEP4729261A1A method for forming a cellulose product in a dry-forming mould system
Publication Date: 2026.04.22 PULPAC AB
  • EP4729261A1 patent drawingFigure 1a~1b
  • EP4729261A1 patent drawingFigure 1c~1d
  • EP4729261A1 patent drawingFigure 1e

AI summary

A method for dry-forming a cellulose product in a dry-forming mould system from an air-formed cellulose blank structure. The dry-forming mould system comprises a forming mould having a first mould part and an opposing second mould part arranged to cooperate with each other in a pressing direction upon forming of the cellulose product. The method comprises the steps: providing the air-formed cellulose blank structure and arranging the cellulose blank structure in the forming mould between the first mould part and the second mould part, wherein the cellulose blank structure has a moisture content in the range of 4-15 wt%, preferably in the range of 6-10 wt%, when arranged between the first mould part and the second mould part; forming the cellulose product by pressing and heating the cellulose blank structure when arranged between the first mould part and the second mould part in a single pressing operation, wherein in the single pressing operation the cellulose blank structure is pressed with a forming pressure in the range of 1-100 MPa, preferably in the range of 8-20 MPa, and heated to a forming temperature in the range of 100-200 °C, preferably in the range of 120-170 °C.