Differential Speed Bonding for Disposable Undergarment Chip Removal

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Solution Overview

Problem

The existing methods for producing disposable undergarments, such as diapers, face challenges in efficiently removing unwanted web material portions like leg holes due to die wear, leading to incomplete cuts and increased die change-outs, which affect production efficiency and quality.

Innovation Solution

An apparatus utilizing rotationally variable speed shoes and transfer rolls to create bond zones and efficiently separate web material from chips by controlling rotational speeds to achieve effective ripping, allowing for continuous and discontinuous side-by-side bonding, thereby extending die life and improving production efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If die cutting is used to remove chip portions from the web, then leg holes and void spaces are created in the undergarment, but die wear causes duller cuts and incomplete separation of chips from the web

Engineering Contradiction:
Improvecut qualityVSAvoiddie life
Core Design Contradiction:
Manufacturing precisionVSDuration of action of stationary object

Solution Approach 1:

The patent replaces the traditional mechanical die-cutting system with a tearing system that uses differential rotation between a shoe and transfer roll to create relative motion and separate chips from the web through controlled tearing rather than mechanical cutting, eliminating die wear issues

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

Solution Approach 2:

The patent introduces a shoe as an intermediary component between the web and the separation mechanism. The shoe receives chips from the die-anvil system and uses rotational speed differential to tear chips away from the web, serving as a mediator that eliminates the need for direct die contact

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If die change-outs are performed frequently to maintain cut quality, then manufacturing precision is maintained, but production efficiency and productivity decrease

Engineering Contradiction:
Improvecut qualityVSAvoidproduction efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent replaces the mechanical die-cutting system with a tearing system that uses differential rotation between a shoe and transfer roll to create relative motion and separate chips from the web through controlled tearing rather than mechanical cutting, eliminating die wear issues

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

Solution Approach 2:

The patent uses a shoe and transfer roll system that can operate continuously without wear, replacing the need for frequent die changes. The system accepts minor imperfections in chip separation while maintaining overall product quality, effectively treating the separation mechanism as a disposable or low-maintenance component

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Stability of the object's composition

If multiple layers are adhesively joined to form the completed undergarment, then proper shape and layer retention are achieved, but complex bonding operations increase process time and reduce productivity

Engineering Contradiction:
Improvelayer retentionVSAvoidbonding efficiency
Core Design Contradiction:
Stability of the object's compositionVSProductivity

Solution Approach 1:

The patent combines multiple bonding operations into a single continuous bonding zone where all layers are adhesively joined simultaneously in one pass rather than through multiple sequential bonding steps, reducing process time while maintaining layer retention

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent implements continuous bonding along the entire length of the undergarment as the web moves through the bonding zone, eliminating intermittent bonding operations and maintaining continuous production flow, thereby improving productivity while ensuring consistent layer retention

Inventive Principle:
Principle #20Continuity of useful action

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 solution enhances the efficiency of chip removal and bonding processes, reducing die change-outs and ensuring consistent quality by maintaining sharp cuts and effective separation of web material, thus prolonging die usage and improving manufacturing productivity.

Implementation Method 1

a rotationally variable speed shoe for receiving a chip, a rotationally constant speed transfer roll for receiving a portion of a web from a die and anvil system

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

next slowing in rotational speed to allow said portion of said web to rip away from said chip at a leading rotational edge of said chip, next increasing in rotational speed to allow said chip to rip away from said web at a trailing rotational edge of said chip

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Implementation Method 3

Each of these layers needs to be adhesively joined at some point in the manufacturing process to the elastic web laminate to form the completed undergarment

Methodology Applied
Scientific EffectAdhesive: Adhesive

Data Source

PatentEP2548540B1Differential speed shafted machines and uses therefor, including discontinuous and continuous side by side bonding
Publication Date: 2019.05.29 JOA CURT G INC
  • EP2548540B1 patent drawingFigure 1~2
  • EP2548540B1 patent drawingFigure 3
  • EP2548540B1 patent drawingFigure 4~6

AI summary

An apparatus having independently rotating shafts for producing discontinuous and continuous side by side bonding using independently rotating bonding units.