Segmented Ductor Roll Assembly for Consistent Can Ink Transfer

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Solution Overview

Problem

Conventional can decorating machines face issues with ink inconsistencies, such as ink starvation and variation in film thickness, due to the need for adjusting fountain keys to achieve zero ink transfer in non-image areas, leading to wear and loss of zero key settings.

Innovation Solution

The introduction of a ductor roll assembly with a modular design featuring a roll portion comprising a plurality of ink transfer segments and spacer segments, allowing selective ink transfer and non-transfer regions, which are rotatably coupled to pivot arms for precise ink distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If fountain keys are adjusted to achieve zero ink transfer in non-image areas, then ink transfer control is improved, but component wear increases and zero key settings are lost

Engineering Contradiction:
Improveink transfer controlVSAvoidcomponent wear and setting retention
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The ductor roll is divided into multiple independent segments (image area segments and non-image area segments) that can be selectively positioned. This segmentation eliminates the need for continuous fountain key adjustment by providing discrete ink transfer zones, thereby reducing component wear while maintaining precise ink transfer control.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The ductor roll segments are made rotatable relative to the ductor roll axis, allowing dynamic positioning of ink transfer segments against the fountain roll. This dynamic adjustment mechanism replaces static fountain key settings, eliminating wear from continuous adjustment while maintaining precise ink transfer control through rotational positioning.

Inventive Principle:
Principle #15Dynamics

2Device complexity

If conventional ductor roll design is used, then结构简单性 is maintained, but ink consistency deteriorates due to ink starvation and film thickness variation

Engineering Contradiction:
Improveductor roll structureVSAvoidink film thickness consistency
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The ductor roll surface is segmented into multiple independent ink transfer segments that can be selectively positioned. This segmentation allows precise control of ink distribution to different zones of the fountain roll, eliminating ink starvation and ensuring consistent ink film thickness across all image areas while maintaining relatively simple overall structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different segments of the ductor roll can be independently positioned to contact or avoid contact with specific zones of the fountain roll. This local quality control ensures that each image area receives appropriate ink transfer while non-image areas receive no ink, thereby achieving consistent ink film thickness without complex overall structure.

Inventive Principle:
Principle #3Local quality

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 design addresses ink inconsistencies by enabling controlled ink transfer, reducing wear on components and maintaining consistent ink film thickness, thereby enhancing the decorating process efficiency and accuracy.

Implementation Method 1

The number of ink transfer segments, each having an ink transfer surface structured to transfer ink between a corresponding axial portion of a fountain roll and a corresponding axial portion of a distributor roll

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4291409B1Ductor roll assembly, ink station assembly and can decorator employing same
Publication Date: 2025.10.29 STOLLE MACHINERY CO LLC
  • EP4291409B1 patent drawingFigure 1
  • EP4291409B1 patent drawingFigure 2
  • EP4291409B1 patent drawingFigure 3

AI summary

A ductor roll assembly for use in an ink station assembly of a can decorator for communicating ink from a fountain roll to a distributor roll. The ductor roll assembly having a roll portion including an elongated axial member and a plurality of segments selectively disposed on and around the axial member axially adjacent each other for rotation about a rotation axis. The plurality of segments includes: a number of ink transfer segments, each ink transfer segment having an ink transfer surface disposed at a first radial distance from the rotation axis and structured to transfer ink between a corresponding axial portion of a fountain roll and a corresponding axial portion of a distributor roll; and a number of spacer segments having a second outer diameter less than the first outer diameter.