Paper Packaging Sheet Heat Sealing for Individually Wrapped Absorbent Articles

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Solution Overview

Problem

The sealing strength of paper packaging sheets in individually packaged absorbent articles is insufficient compared to resin-based sheets, and using heat sealing agents increases costs, necessitating a more efficient method to form reliable seals.

Innovation Solution

A paper packaging sheet with a heat sealing agent applied to specific regions, using a barrier agent-uncoated or lightly coated sheet, and optimizing the coating weight and density to enhance sealing strength through heat sealing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a heat sealing agent is used to form a sealing portion in a paper packaging sheet, then the sealing strength is improved, but the manufacturing cost increases

Engineering Contradiction:
Improvesealing strengthVSAvoidmanufacturing cost
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The heat sealing agent is applied selectively only to the sealing portion regions of the packaging sheet rather than the entire surface. This localized application reduces the quantity of sealing agent required, thereby lowering manufacturing costs while maintaining adequate sealing strength at the critical sealing areas where heat is applied during packaging.

Inventive Principle:
Principle #3Local quality

2Ease of manufacture

If a paper packaging sheet is used instead of resin film, then the environmental friendliness and cost are improved, but the sealing strength is insufficient

Engineering Contradiction:
ImprovecostVSAvoidsealing strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The heat sealing agent acts as an intermediary substance that facilitates bonding between the paper packaging sheet layers. When heat is applied, the sealing agent melts and adheres to the paper fibers, creating strong bonds that compensate for paper's inherent inferior sealing properties compared to resin films, thus enabling paper to achieve adequate sealing strength.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-generated harmful factors

If the coating weight of barrier agent is increased, then the prevention of agent seepage is improved, but the heat sealing efficiency is reduced

Engineering Contradiction:
Improveagent seepageVSAvoidheat sealing efficiency
Core Design Contradiction:
Object-generated harmful factorsVSProductivity

Solution Approach 1:

The invention optimizes the barrier agent coating weight parameter to a specific range (5-15% of total basis weight). This optimized parameter range provides sufficient barrier protection to prevent sealing agent seepage through the packaging sheet while maintaining adequate porosity and surface properties that allow the heat sealing agent to be applied and activated effectively during the sealing process.

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 method achieves reliable heat sealing with reduced heat sealing agent usage, enhancing sealing strength and preventing agent seepage, thus improving packaging integrity and user experience.

Implementation Method 1

a heat sealing agent is provided on at least a region included in the sealing portion of one of the inner surface and the outer surface of the packaging sheet

Methodology Applied
Scientific EffectHeat sealing: Heating

Implementation Method 2

sealing both edge portions in a lateral direction orthogonal to the longitudinal direction

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP4691438A1Individually-packaged absorbent article
Publication Date: 2026.02.11 DAIO PAPER CORP
  • EP4691438A1 patent drawingFigure 1
  • EP4691438A1 patent drawingFigure 2
  • EP4691438A1 patent drawingFigure 3~5

AI summary

In an individually packaged absorbent article formed by wrapping an absorbent article in a packaging sheet made of paper, a sealing portion is formed by folding the packaging sheet toward an inner surface side in a longitudinal direction of the packaging sheet and sealing both edge portions in a lateral direction orthogonal to the longitudinal direction, a heat sealing agent is provided on at least a region included in the sealing portion of one of the inner surface and the outer surface of the packaging sheet, and the packaging sheet is a barrier agent-uncoated sheet or a barrier agent-coated sheet, and a coating weight of the barrier agent is 10% or less with respect to a total basis weight of the packaging sheet after the heat sealing agent is provided.