Direct Printing Machine Ink Supply System With Header Tank

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Solution Overview

Problem

Direct printing machines face challenges in maintaining a closed ink flow and automatic flushing of the ink supply system, leading to time-consuming maintenance and potential print quality issues due to the need for disconnecting ink supply and return lines.

Innovation Solution

The implementation of a header tank system with a valve island between the tank and the direct print head allows for precise control of ink flow, enabling automated flushing and bubble removal, reducing the need for ink pumps and enhancing print quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the ink supply system uses a conventional design with disconnectable feed and return lines, then maintenance and commissioning can be performed, but the process becomes time-consuming and automatic flushing becomes impossible

Engineering Contradiction:
Improvemaintenance operationVSAvoidmaintenance time
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The ink supply system is segmented into a stationary part (reservoir, feed line, valve manifold) and a moving part (header tank with direct printhead), allowing the moving part to be easily detached and replaced without disrupting the stationary ink supply infrastructure. This enables quick maintenance operations while maintaining automatic flushing capability through the stationary portion's integrated flushing valve.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A flushing valve is introduced as an intermediary component in the feed line between the reservoir and the direct printhead. This flushing valve enables automatic flushing of the ink supply system without requiring disconnection of any components, thereby eliminating maintenance time loss while preserving ease of operation through simple valve actuation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the ink supply system is designed as a closed flow system, then print quality is improved, but the system complexity increases and automatic flushing becomes difficult

Engineering Contradiction:
Improveprint qualityVSAvoidink supply system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The feed line serves multiple functions: it supplies ink to the direct printhead during normal operation and acts as a flushing pathway when the flushing valve is activated. This multi-functionality maintains the closed flow system for print quality while avoiding additional complexity by reusing existing infrastructure for flushing purposes.

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

Solution Approach 2:

The ink supply system performs self-flushing through the integrated flushing valve in the feed line, eliminating the need for external flushing mechanisms or system disassembly. The system serves its own maintenance needs automatically, maintaining print quality reliability without increasing device complexity.

Inventive Principle:
Principle #25Self-service

3Reliability

If multiple ink pumps are used to maintain ink flow, then print quality is ensured, but the initial costs and system complexity increase

Engineering Contradiction:
Improveprint qualityVSAvoidnumber of ink pumps
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The header tank maintains continuous ink circulation to the direct printhead through its integrated design, eliminating the need for additional pumps. The tank's structure and positioning ensure continuous ink flow and pressure regulation, maintaining print quality reliability without adding system complexity or requiring multiple ink pumps.

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 simplifies the creation of a closed ink flow, allows for automatic flushing, and reduces the number of ink pumps required, resulting in higher print quality and lower initial costs for ink supply systems.

Implementation Method 1

at least one header tank arranged in the forward and/or return direction, a predefined meniscus pressure of the printing ink at the direct printhead can be precisely set

Methodology Applied
Scientific EffectGravitational force: Gravitation

Data Source

PatentEP3450179B1Direct printing machine and method for printing on containers by means of direct printing
Publication Date: 2020.09.30 KRONES AG
  • EP3450179B1 patent drawingFigure 1
  • EP3450179B1 patent drawingFigure 2
  • EP3450179B1 patent drawingFigure 3

AI summary

Direct printing machine (1) for printing containers (2) with a direct print, comprising at least one stationary direct printing station (5W, 5C, 5M, 5Y, 5K) with a direct printhead (50) for printing the containers (2) with the direct print, an ink supply system (6) for supplying the direct printhead (50) with printing ink (60a) from a reservoir (60), and a conveyor (3) for conveying the containers (2) past the least one stationary direct printing station (5W, 5C, 5M, 5Y, 5K), wherein the ink supply system (6) comprises a feed (6v) and/or a return (6r) for the printing ink (60a) to establish an ink flow from the reservoir (60) to the direct printhead (50) and/or back, characterized in that the ink supply system (6) has at least one feed (6v) and/or return (6r) arranged header tank (61a, 61b) to set a meniscus pressure of the printing ink (60a) towards the direct printhead (50),and that a valve manifold (62) is arranged between the at least one header tank (61a, 61b) and the direct printhead (50) in order to interrupt the ink flow via the direct printhead (50) and to establish it in a bypass line (62d) parallel to the direct printhead (50).