Coreless roll of absorbent sheet and method for manufacturing the same

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Solution Overview

Problem

Coreless rolls of absorbent sheet products face issues with collapsing, lack of elasticity, and difficulty in maintaining a defined axial hollow passageway, leading to perception of decreased quality and increased storage and transport costs.

Innovation Solution

A coreless roll design featuring a spirally wound continuous web of absorbent material with a coating composition applied to at least 20% of its length, providing superior resiliency and elasticity, allowing the roll to maintain its shape and reopen the axial hollow passageway effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of stationary object

If coreless rolls are made without a stiff core, then storage space and handling costs are reduced, but the roll collapses and loses its defined axial hollow passageway

Engineering Contradiction:
Improvestorage spaceVSAvoidaxial hollow passageway definition
Core Design Contradiction:
Volume of stationary objectVSStability of the object's composition

Solution Approach 1:

The patent applies parameter changes by treating the absorbent sheet material with chemical crosslinking agents that modify the physical and chemical properties of the material. This crosslinking increases the material's resistance to deformation and collapsing, enabling the coreless roll to maintain its axial hollow passageway definition without requiring a stiff core, thus resolving the contradiction between reduced storage space and structural stability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite structure by combining the absorbent sheet material with crosslinked polymer networks formed through chemical treatment. This composite material exhibits enhanced mechanical properties including improved resistance to collapsing and deformation, allowing the roll to maintain its shape and axial hollow passageway without a traditional stiff core

Inventive Principle:
Principle #40Composite materials

2Volume of stationary object

If the roll is compressed for storage, then storage and transport costs are reduced, but the roll must recover its shape to maintain quality perception

Engineering Contradiction:
Improvestorage volumeVSAvoidcylindrical form recovery
Core Design Contradiction:
Volume of stationary objectVSShape

Solution Approach 1:

The chemical crosslinking treatment fundamentally changes the viscoelastic parameters of the absorbent sheet material, transforming it from a material that permanently deforms under compression to one that exhibits elastic recovery. This parameter change enables the roll to be compressed for storage and then recover its cylindrical shape upon unpacking, maintaining quality perception while reducing storage volumes

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If the continuous web lacks sufficient stiffness, then flexibility for compression is improved, but the roll cannot resist deformation forces during storage and transport

Engineering Contradiction:
Improvecompression flexibilityVSAvoidresistance to deformation
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The patent applies parameter changes through controlled chemical crosslinking that selectively modifies the mechanical properties of the absorbent sheet. The crosslinking density and distribution are optimized to provide sufficient stiffness for resisting deformation forces during storage and transport, while maintaining enough flexibility to allow compression for storage purposes

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite material system where the absorbent sheet is combined with a crosslinked polymer network. This composite exhibits optimized mechanical properties that balance flexibility and strength, allowing the roll to be compressed for storage while simultaneously resisting deformation forces during storage and transport

Inventive Principle:
Principle #40Composite materials

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 enhances the roll's ability to recover its original shape and size, maintaining a well-defined axial hollow passageway and reducing storage and transport costs while preventing sewage clogging.

Implementation Method 1

the roll must exhibit a certain level of 'elasticity' such that it can substantially return by itself from the compressed (oval) form to the uncompressed (cylindrical) form

Methodology Applied
Scientific EffectElastic recovery: Elasticity

Data Source

PatentEP3688224B1Coreless roll of absorbent sheet and method for manufacturing the same
Publication Date: 2022.06.15 ESSITY HYGIENE & HEALTH AB
  • EP3688224B1 patent drawingFigure 1~2
  • EP3688224B1 patent drawingFigure 3~4
  • EP3688224B1 patent drawingFigure 5~6

AI summary

The present invention relates to a coreless roll of an absorbent sheet product such as napkins, toilet paper, towels etc. made of a spirally wound continuous web of absorbent material having a first end and a second end, wherein a coating composition comprising a specific polymer is coated onto the continuous web. The coreless roll of the present invention has excellent resistance to collapsing, as well as excellent flexibility, elasticity and resiliency. Moreover, the coreless roll of the present invention has excellent disintegrability in water and can be used up over its whole length. The present invention also relates to a process for the manufacture of the coreless roll.