Layered Elastic Substrate Differential Speed Metering

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Solution Overview

Problem

Existing methods for manufacturing absorbent articles, such as diapers, face challenges in creating waistbands with different contraction amounts, which can improve fit but add complexity and cost to the assembly process.

Innovation Solution

A method and apparatus for making a single layered elastic substrate that can be cut into discrete waistbands with varying contraction levels by advancing elastic materials and substrate layers through metering devices at controlled speeds, allowing for differential elongation and consolidation to create waistbands with specific contraction properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If multiple separate waistbands with different contraction levels are produced, then the fit of the absorbent article is improved, but the manufacturing complexity and cost increase

Engineering Contradiction:
Improvecontraction level differentiationVSAvoidassembly process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The single elastic substrate is segmented into multiple waistband regions with different contraction levels through differential stretching during manufacturing. The substrate is divided into a first waistband portion and a second waistband portion, each with distinct elastic properties achieved by applying different stretching forces or durations to different sections of the continuous substrate during the bonding process.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the elastic substrate are given different local properties (contraction levels) to meet specific functional requirements. The first waistband portion is engineered with one contraction level while the second waistband portion is engineered with a different contraction level, allowing each region to be optimized for its specific location and function on the absorbent article.

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If multiple separate waistbands with different contraction levels are produced, then the fit of the absorbent article is improved, but the manufacturing cost increases

Engineering Contradiction:
Improvecontraction level differentiationVSAvoidmanufacturing cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

Multiple waistbands with different contraction levels are merged into a single continuous elastic substrate that is manufactured and bonded in one continuous process. This eliminates the need to produce, handle, and assemble multiple separate waistband components, thereby reducing manufacturing cost while maintaining the differentiated contraction levels across different regions of the substrate.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single elastic substrate serves multiple functions simultaneously by providing both a first waistband portion and a second waistband portion with different contraction levels. This multi-functional component replaces what would traditionally require multiple separate components, simplifying the manufacturing process and reducing overall production cost.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Manufacturing precision

If elastic materials are advanced at different speeds through metering devices, then differential elongation is achieved for tailored contraction, but the process control complexity increases

Engineering Contradiction:
Improvedifferential elongation controlVSAvoidmetering device control complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The metering devices are configured with variable speed capabilities that allow dynamic adjustment of material advancement rates during the bonding process. By controlling the relative speeds of the first and second elastic materials as they are advanced through the metering devices, the system achieves differential elongation and gathering effects, creating regions with different contraction levels in a controlled manner.

Inventive Principle:
Principle #15Dynamics

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

Enables the production of absorbent articles with improved fit by creating waistbands with tailored contraction, simplifying the manufacturing process and reducing costs associated with producing multiple waistbands with distinct contraction levels.

Implementation Method 1

advancing a first elastic material in a machine direction to a first metering device at a speed, V1, wherein the first elastic material is in a stretched state; advancing a second elastic material in the machine direction to a second metering device at a speed, V2, wherein the second elastic material is in a stretched state

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

V1 is less than V2, wherein V3 is greater than V1 and V2... bonding the first and second elastic materials in the stretched states to the first surface of the first substrate layer and the first surface of the second substrate layer

Methodology Applied
Scientific EffectDifferential elongation: Deformation

Data Source

PatentEP2866759B1Apparatus and method for making a layered elastic substrate
Publication Date: 2016.10.26 PROCTER & GAMBLE CO
  • EP2866759B1 patent drawingFigure 1
  • EP2866759B1 patent drawingFigure 2A~2D
  • EP2866759B1 patent drawingFigure 2E~2J

AI summary

A first elastic material is advanced in a machine direction in a stretched state to a first metering device at a speed, V1. A second elastic material is advanced in the machine direction in a stretched state to a second metering device at a speed, V2. First and second substrate layers are advanced in a machine direction to a third metering at a speed, V3, along with the first and second elastic materials. The first and second elastic materials are bonded to the first and second substrate layers at the third metering device to form a layered elastic substrate. The layered elastic substrate is advanced to a fourth metering device at a speed, V4. V1 is less than V2, V3 is greater than V1 and V2, V4 is less than V3, and V4 is greater than V1 and V2.