Ultrasonic Paper Sheet Bonding Without Adhesive or Through Holes

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Solution Overview

Problem

Existing methods for bonding paper sheets without thermally fusible components face challenges such as weak bonding strength, texture deterioration, and increased material costs, particularly when using no adhesive or heat embossing, and the formation of through holes when creating fine holes.

Innovation Solution

The method involves pressing a second paper sheet with pulp fibers against a first paper sheet and applying ultrasonic waves to accelerate fiber crystallization at the bonding area, achieving mechanical interlocking without thermal fusion, while maintaining a high degree of gloss and suppressing texture deterioration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the method of forming fine holes is used to bond paper sheets, then bonding is achieved, but liquid permeation increases and texture deteriorates

Engineering Contradiction:
Improvebonding strengthVSAvoidtexture deterioration
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent replaces thermal fusion (heat-based mechanical system) with ultrasonic vibration (acoustic field) to achieve bonding. The ultrasonic waves cause fibers to vibrate and interlock mechanically without melting or forming holes, thus maintaining texture while achieving strong bonding between paper sheets.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent applies ultrasonic vibration to the pressed portion of overlaid paper sheets. This mechanical vibration accelerates fiber crystallization and enables fibers to entangle and bond together without thermal fusion, achieving strong bonding while preserving the original texture and avoiding hole formation.

Inventive Principle:
Principle #18Mechanical vibration

2Loss of substance

If the method of overlaying sheets through no adhesive agent and performing embossing is used, then material cost is reduced, but bonding strength becomes weak

Engineering Contradiction:
Improvematerial costVSAvoidbonding strength
Core Design Contradiction:
Loss of substanceVSStrength

Solution Approach 1:

The patent uses ultrasonic vibration applied to pressed portions of overlaid paper sheets to achieve strong bonding without adhesive agents. The vibration accelerates fiber crystallization and creates mechanical interlocking between fibers, providing sufficient bonding strength while eliminating adhesive material costs.

Inventive Principle:
Principle #18Mechanical vibration

Solution Approach 2:

The patent replaces adhesive-based bonding with ultrasonic vibration-induced fiber entanglement. This substitution eliminates the need for adhesive agents (reducing material cost) while achieving comparable or superior bonding strength through mechanical fiber interlocking.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Strength

If the method of overlaying papers through adhesive agent and performing embossing is used, then bonding strength is improved, but material cost increases

Engineering Contradiction:
Improvebonding strengthVSAvoidmaterial cost
Core Design Contradiction:
StrengthVSLoss of substance

Solution Approach 1:

The patent replaces adhesive agent-based bonding with ultrasonic vibration-induced fiber entanglement. This substitution eliminates adhesive material costs while maintaining or improving bonding strength through mechanical interlocking of fibers at the pressed portions.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent enables paper fibers to bond with each other through self-entanglement induced by ultrasonic vibration. The fibers themselves perform the bonding function without requiring external adhesive agents, achieving cost reduction while maintaining bonding strength.

Inventive Principle:
Principle #25Self-service

4Strength

If heat embossing is used to bond paper sheets, then bonding is achieved, but texture deteriorates due to heating

Engineering Contradiction:
Improvebonding strengthVSAvoidtexture deterioration
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent uses ultrasonic vibration instead of heat embossing to achieve bonding. The mechanical vibration accelerates fiber crystallization and creates strong bonds without thermal exposure, thereby avoiding texture deterioration while maintaining bonding strength.

Inventive Principle:
Principle #18Mechanical vibration

Solution Approach 2:

The patent replaces thermal fusion (heat-based system) with ultrasonic vibration (acoustic field) for bonding paper sheets. This substitution eliminates thermal damage to the paper texture while achieving equivalent or superior bonding strength through fiber entanglement.

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

This approach enables strong bonding of paper sheets without through holes or adhesive use, maintaining texture quality and reducing material costs, with a bonding area gloss that enhances appearance and functionality.

Implementation Method 1

applying ultrasonic wave to a pressed portion so as to accelerate crystallization of the fibers at the pressed portion

Methodology Applied
Scientific EffectUltrasonic wave: Ultrasound

Implementation Method 2

accelerate crystallization of the fibers at the pressed portion where the first and second paper sheets are bonded together

Methodology Applied
Scientific EffectCrystallization: Crystallisation

Implementation Method 3

pressing the second paper sheet against the first paper sheet

Methodology Applied
Scientific EffectMechanical pressure: Compression

Data Source

PatentEP1870517B1Paper sheet and its bonding method
Publication Date: 2016.03.09 DAIO PAPER CORP
  • EP1870517B1 patent drawingFigure 1
  • EP1870517B1 patent drawingFigure 2~3
  • EP1870517B1 patent drawingFigure 4~5

AI summary

[PROBLEMS] To bond a paper sheet containing no thermally fusible component with sufficient strength without forming a through hole, deteriorating texture and increasing the material cost. [MEANS FOR SOLVING PROBLEMS] While pressing a second paper sheet (11) containing no thermally fusible component against a first paper sheet (10) containing no thermally fusible component, an ultrasonic wave is applied to the press contact portion so that fibers of the second paper sheet (11) enter mechanically between fibers of the first paper sheet (10) thus forming a bonding portion without requiring thermal fusion.