Winding Roller Charge Transfer for Electrostatic Safety

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Solution Overview

Problem

Rotary printing presses face issues with unwanted charging of web materials due to electrostatic printing aids, leading to voltage flashovers and safety hazards during processing and handling, especially when using insulating materials like plastic films and composite materials.

Innovation Solution

A winding device that transfers electrical charges of opposite polarity to the web material on the take-up roll, using a device connected to a high-voltage source, either positive or negative, to compensate for existing charges, thereby preventing re-charging and reducing unwanted electrostatic buildup.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If electrostatic printing aids are used to improve ink transfer, then print quality is improved, but unwanted electrostatic charging of the web material occurs

Engineering Contradiction:
Improveprint qualityVSAvoidelectrostatic charging
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent applies a semiconducting layer to the pressure cylinder that utilizes the electrostatic charging effect to create a controlled electric field for improved ink transfer, while simultaneously managing the harmful electrostatic buildup on the web material through the layer's specific electrical properties

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent changes the electrical resistance parameter of the pressure cylinder surface by applying a semiconducting layer with specific resistance values (10^6 to 10^9 ohm/cm), which allows controlled charge distribution and dissipation to prevent unwanted electrostatic charging of the web material

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If a semiconducting layer is applied to the pressure cylinder to control electrical currents, then spark generation is prevented, but the complexity of the pressure cylinder structure increases

Engineering Contradiction:
Improvespark generationVSAvoidpressure cylinder structure
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent applies a semiconducting layer (such as carbon-loaded rubber or polyurethane) onto the pressure cylinder surface, creating a composite structure that combines the mechanical properties of the cylinder with the electrical properties of the semiconducting material to control current flow and prevent sparks

Inventive Principle:
Principle #40Composite materials

3Manufacturing precision

If high voltage is applied to the pressure cylinder to enhance ink transfer, then print quality is improved, but safety hazards increase due to voltage flashovers

Engineering Contradiction:
Improveprint qualityVSAvoidoperational safety
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent carefully controls the electrical resistance parameter of the semiconducting layer to manage voltage distribution, allowing high voltage application for improved ink transfer while preventing dangerous voltage flashovers through controlled charge dissipation

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The semiconducting layer acts as an intermediary between the high voltage source and the web material, mediating the electrical interaction to achieve improved ink transfer while preventing direct high voltage discharge that would cause safety hazards

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Effectively minimizes electrostatic charging of the web material, preventing voltage flashovers and ensuring safer handling and processing by compensating for charges on the take-up roll, thus enhancing operational safety and reducing hazards.

Implementation Method 1

A winding device is described which transfers electrical charges of opposite polarity to the web material on the take-up roll (15).

Methodology Applied
Scientific EffectElectrostatic charge transfer: Electrostatic Induction

Implementation Method 2

using a device connected to a high-voltage source, either positive or negative, to compensate for existing charges

Methodology Applied
Scientific EffectElectric field force: Electric Field

Data Source

PatentEP3222421B1Winding apparatus with electric charging of the web material
Publication Date: 2021.12.15 DETTKE CHRISTA
  • EP3222421B1 patent drawingFigure 1
  • EP3222421B1 patent drawingFigure 2(a)~2(f)
  • EP3222421B1 patent drawingFigure 3

AI summary

Winding device for an electrically essentially insulating web material (12) with a winding roller (15) onto which the web material can be wound, characterized in that a device (28, 34) for transferring electrical charge to the web material is provided on the winding roller and/or when deflecting onto the winding roller and the device for transferring electrical charge is connected to at least one high-voltage electrical source of positive or negative polarity.