Ink Circuit Pumping for Flexographic Press Conversion

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Solution Overview

Problem

Flexographic and gravure printing machines face high conversion costs due to the need for frequent press changes and the use of solvents requiring special explosion protection, which limits the efficiency of ink circuits.

Innovation Solution

An annular piston pump driven by an asynchronous motor with field-oriented control is used as the discharge pump, allowing for direct electric motor operation and reducing energy consumption, noise, and ink loss, while enabling precise control of ink viscosity and flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If air-operated diaphragm pumps are used for ink circulation, then explosion protection requirements are met, but energy consumption increases and noise levels rise

Engineering Contradiction:
Improveexplosion protectionVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent replaces air-operated diaphragm pumps with electrically driven piston pumps. This substitution eliminates the need for compressed air while maintaining safe operation with solvent-containing inks through intrinsic safety design, thereby reducing energy consumption and noise levels.

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

Solution Approach 2:

The patent changes the operating parameters by using electric motors with controlled speed and torque characteristics instead of air pressure operation. This allows precise control of ink circulation while maintaining explosion safety through controlled electrical parameters in potentially explosive atmospheres.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If air-operated diaphragm pumps are used for ink circulation, then explosion protection requirements are met, but noise emission increases

Engineering Contradiction:
Improveexplosion protectionVSAvoidnoise emission
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent replaces air-operated diaphragm pumps with electrically driven piston pumps, eliminating the noisy compressed air system while maintaining explosion protection through intrinsically safe electrical design, thereby significantly reducing noise emission.

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

3Productivity

If conventional pumps are used for ink circulation, then ink can be circulated, but ink loss during press changes increases

Engineering Contradiction:
Improveink circulationVSAvoidink loss
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The patent replaces conventional pumps with piston pumps that feature precise metering capabilities and lower dead volumes. This allows for more efficient ink circulation with minimal residual ink in the system, significantly reducing ink loss during press changes and color conversions.

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

Solution Approach 2:

The patent uses variable speed control and precise flow rate regulation of the piston pump to optimize ink circulation during different operating phases, minimizing unnecessary circulation and reducing ink loss during press changes.

Inventive Principle:
Principle #35Parameter changes

4Use of energy by moving object

If piston pumps are used for ink circulation, then energy consumption decreases, but precise control of ink viscosity and flow is required

Engineering Contradiction:
Improveenergy consumptionVSAvoidcontrol system complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent incorporates feedback control systems that monitor ink viscosity and flow rate, automatically adjusting pump parameters to maintain optimal circulation conditions. This feedback mechanism simplifies operation while achieving precise control with reduced energy consumption.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent uses variable speed control and adjustable flow parameters of the piston pump to adapt to different ink viscosities and circulation requirements, enabling precise control while maintaining energy efficiency through optimized operating parameters.

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

This solution significantly reduces energy consumption, noise, and ink loss during press changes, minimizing conversion costs and optimizing ink control, thereby reducing overall printing costs and maintaining ink quality.

Implementation Method 1

an asynchronous motor with field-oriented control in which the motor states speed, slip and torque are determined on the basis of the magnitude and phase position of the instantaneous current to the voltage

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a pump for the drain pump that is driven directly by an electric motor. A key insight of the invention is that, under certain conditions, a pump driven directly by an electric motor can indeed be used as a discharge pump and/or as a feed pump

Methodology Applied
Scientific EffectMechanical displacement pumping: Pump

Data Source

PatentEP3334605B1Ink circuit of an inking unit of a flexographic or gravure printing press
Publication Date: 2020.11.18 WINDMOELLER & HOELSCHER GMBH
  • EP3334605B1 patent drawingFigure 1

AI summary

The invention relates to an ink circuit of an inking unit of a flexographic or gravure printing press. In order to reduce the changeover costs in relation to the ink circuit of an inking unit of a flexographic or gravure printing press, an ink circuit of an inking unit of a flexographic or gravure printing press is provided, wherein the inking unit has an ink inflow for providing ink which is ready for printing and an ink outflow for transporting away excess ink, wherein the ink inflow is operated by an inflow pump and the ink outflow is operated by an outflow pump, and wherein the outflow pump is a pump which is driven by an electric motor.