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 challenges with collapsing during manufacturing, storage, and transport, leading to difficulties in maintaining a stable axial hollow passageway and increased risk of clogging sewage systems, while existing solutions lack sufficient flexibility and elasticity, and often result in irreversible deformation and decreased product quality.

Innovation Solution

A coreless roll design featuring a continuous web of absorbent material with a coating composition comprising a nonionic cellulose ether applied to the second end, which provides excellent stiffness, resistance to collapsing, and flexibility, allowing the roll to maintain a well-defined axial hollow passageway and prevent sewage clogging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If coreless rolls are made without a temporary core, then storage and transport space is reduced and manual handling is simplified, but the roll collapses and the axial hollow passageway becomes unstable

Engineering Contradiction:
Improvestorage and transport spaceVSAvoidaxial hollow passageway stability
Core Design Contradiction:
Volume of moving objectVSStability of the object's composition

Solution Approach 1:

The patent applies a coating composition containing cellulose ether to the second end of the continuous web. This chemical modification changes the physical parameters of the paper material, providing stiffness and structural support that prevents roll collapse while maintaining the coreless design for space-efficient storage and transport.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite structure by applying a cellulose ether coating to the absorbent sheet material. This composite combines the absorbent properties of the paper web with the structural reinforcement of the cellulose ether coating, achieving both collapse resistance and coreless design benefits.

Inventive Principle:
Principle #40Composite materials

2Adaptability or versatility

If the roll is made flexible to allow compression for storage, then storage and transport costs are reduced, but the roll becomes prone to irreversible deformation and quality degradation

Engineering Contradiction:
Improvecompressibility for storageVSAvoidproduct quality consistency
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The cellulose ether coating modifies the mechanical parameters of the paper web, creating an optimal balance between flexibility and structural integrity. This allows the roll to be compressed for storage while maintaining sufficient stiffness to prevent irreversible deformation and quality degradation during handling and use.

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If a temporary core is used during manufacturing, then the axial hollow passageway is maintained during winding, but the core requires additional storage space and manual handling

Engineering Contradiction:
Improveaxial hollow passageway maintenance during windingVSAvoidcore removal and handling process
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent extracts the temporary core from the manufacturing process entirely, achieving a true coreless design. The cellulose ether coating on the second end provides sufficient structural support to maintain the axial hollow passageway during winding without requiring any core material, thereby eliminating storage and handling requirements for cores.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The absorbent sheet material itself, through the cellulose ether coating, provides the structural support function that would otherwise require a separate core component. The coated second end self-reinforces to maintain the hollow passageway during the winding process, making the core unnecessary.

Inventive Principle:
Principle #25Self-service

4Stability of the object's composition

If the first inner turns are tightly wound to define the axial hollow passageway, then the passageway is clearly defined, but the roll becomes stiff and resistant to compression

Engineering Contradiction:
Improveaxial hollow passageway definitionVSAvoidcompressibility
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The cellulose ether coating changes the local mechanical parameters of the paper at the second end, providing targeted stiffness where needed for passageway definition while allowing the rest of the roll to remain compressible. This localized parameter modification resolves the contradiction between structural definition and overall flexibility.

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

The coreless roll exhibits improved stiffness and resistance to collapsing, maintaining a stable axial hollow passageway and preventing sewage clogging, while allowing for full-length use and reduced storage and transport costs, enhancing product quality and usability.

Implementation Method 1

the absorbent sheet product constituting the first inner turns of the roll (i.e. the turns forming the axial hollow passageway at winding start) cannot be stably maintained

Methodology Applied
Scientific EffectViscoelasticity: Viscoelasticity

Implementation Method 2

the roll can be returned from its compressed (oval) form to the uncompressed (cylindrical) form by applying pressure along the longer diameter

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

the continuous web of absorbent material being wound such as to define an axial hollow passageway

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP3688226B1Coreless roll of absorbent sheet and method for manufacturing the same
Publication Date: 2021.11.24 ESSITY HYGIENE & HEALTH AB
  • EP3688226B1 patent drawingFigure 1~2
  • EP3688226B1 patent drawingFigure 3
  • EP3688226B1 patent drawingFigure 4a~4b

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 nonionic cellulose ether is coated onto the second end. The coreless roll of the present invention has excellent stiffness and resistance to collapsing, as well as sufficient flexibility and elasticity. 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.