Oscillating Cutter Winding Device for Stretch Film Edge Control

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Solution Overview

Problem

Existing winding devices for stretch films face issues with edge damage during wrapping, leading to film tears, and existing methods for folding edges to prevent damage either result in thick edges or creases, complicating the winding process.

Innovation Solution

An oscillating device moves the cutter bar transversely to the film direction, allowing for lateral shifting of folded edges, with adjustable stroke and frequency, and a folding device that can handle edges separately or simultaneously, enabling optimal edge geometry without complex additional devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the edges of stretch film are folded over to prevent damage, then resistance to damage is improved, but the edges of the film roll become thick and hard

Engineering Contradiction:
Improveresistance to damageVSAvoidedge thickness
Core Design Contradiction:
ReliabilityVSShape

Solution Approach 1:

The patent applies dynamic oscillation to the folding device, causing it to move laterally during the folding process. This dynamic movement prevents the edges from stacking directly on top of each other, thereby reducing edge thickness while maintaining the protective folded structure. The oscillating motion is controlled to synchronize with the film web speed and roll diameter.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The folding device performs periodic lateral oscillations during the edge folding process. This periodic action creates a rhythmic side-to-side motion that distributes the folded edges along the roll circumference, preventing accumulation at single points and reducing overall edge thickness and hardness.

Inventive Principle:
Principle #19Periodic action

2Reliability

If the film web is reversed or oscillated before winding to fold edges, then edge damage resistance is improved, but creases are produced that impair film function

Engineering Contradiction:
Improveedge damage resistanceVSAvoidcreases
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The folding device is designed with controlled dynamic oscillation that moves laterally during operation. This controlled dynamic motion folds edges without creating sharp creases, as the oscillation distributes stress and prevents concentrated folding lines that would impair film functionality.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system adjusts oscillation parameters including stroke length, frequency, and phase angle to optimize the folding process. By carefully controlling these parameters, the device achieves edge folding that resists damage while minimizing crease formation through precise parameter optimization.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If individual folding devices are provided for each edge to handle them separately, then edge geometry control is improved, but device complexity increases

Engineering Contradiction:
Improveedge geometry controlVSAvoidnumber of folding devices
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent employs a single folding device that performs multiple functions: it folds both edges of the film web, controls edge geometry, and oscillates laterally to reduce edge thickness. This multi-functional approach achieves precise edge control without requiring separate devices for each edge, thereby reducing overall system complexity.

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

Solution Approach 2:

The folding device integrates edge folding, lateral oscillation, and geometry control into a single unified mechanism. By merging these functions into one device rather than using separate devices for each function, the system achieves complex edge control with reduced overall device complexity.

Inventive Principle:
Principle #5Merging (Combining)

4Ease of operation

If the cutter bar is stationary during winding, then winding simplicity is maintained, but lateral shifting of folded edges is not achieved

Engineering Contradiction:
Improvewinding simplicityVSAvoidedge structure
Core Design Contradiction:
Ease of operationVSShape

Solution Approach 1:

The cutter bar is transformed from a stationary component to a dynamically oscillating one. This dynamic oscillation allows the folded edges to be laterally shifted during winding, creating a reduced edge structure. The oscillation is synchronized with the winding process to maintain simplicity while achieving the desired edge geometry.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The cutter bar performs periodic lateral oscillations during the winding process. This periodic movement systematically shifts the folded edges along the roll circumference, creating uniform edge distribution and reduced edge structure without complicating the overall winding operation.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP3080023B1Winding device
Publication Date: 2020.05.27 WINDMOELLER & HOELSCHER GMBH
  • EP3080023B1 patent drawingFigure 1
  • EP3080023B1 patent drawingFigure 2

AI summary

The invention relates to a winding device for winding a running web of material, having at least one cutter for slitting the web of material in the direction of the web into a plurality of web sections, and having a folding device for folding the edges of the web sections. In order to provide a winding device that allows winding a web of material with folded edges as easily as possible and without wrinkles, an oscillating device is provided, by means of which the at least one cutter can be moved transversely to the direction of the web.