Single-Pass Printer Tension Control for Stretchable Materials

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Solution Overview

Problem

Existing printing technologies for long band-shaped objects, such as fastener tapes, face challenges with slow printing speed in multi-pass methods and image distortion or color shift in single-pass methods due to tension variations, especially when printing stretchable materials like cloth.

Innovation Solution

A single-pass printing method and device that uses constant speed driving rollers and tension change detecting dancer rollers with rotary encoders to maintain consistent tension and precise control of conveying speed, preventing stretching and misalignment, allowing for rapid and precise printing on stretchable long band-shaped objects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a multi-pass ink-jet printer is used with dancer rollers for tension control, then position alignment is maintained, but printing speed becomes slow

Engineering Contradiction:
Improveposition alignmentVSAvoidprinting speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent transitions from a static multi-pass printing system to a dynamic single-pass system. The printer head moves continuously in one pass while dancer rollers dynamically adjust tension in real-time. This dynamic approach allows high-speed single-pass printing while maintaining position alignment through active tension control during the printing process.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements continuous printing action by eliminating the reciprocating motion of multi-pass printers. The single-pass configuration allows the printer head to move continuously along the long band-shaped object without stopping or reversing, maintaining continuous useful printing action at high speed while dancer rollers ensure continuous tension control throughout the process.

Inventive Principle:
Principle #20Continuity of useful action

2Productivity

If a single-pass ink-jet printer is used for high-speed printing, then productivity increases, but image distortion and color shift occur due to tension variations

Engineering Contradiction:
Improveprinting speedVSAvoidimage accuracy
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent incorporates feedback control through dancer rollers that continuously monitor tension variations during single-pass printing. The dancer rollers detect changes in material tension and automatically adjust to maintain optimal tension levels, providing real-time feedback control that prevents image distortion and color shift while enabling high-speed continuous printing.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The dancer rollers are positioned upstream of the printing zone to cushion and compensate for tension variations before the material reaches the printer head. This beforehand cushioning prevents tension-induced distortion from affecting the printing process, allowing high-speed single-pass printing to maintain image accuracy by pre-stabilizing the material tension.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Reliability

If dancer rollers are used to detect extra length of the long band-shaped object, then tension control is achieved, but the mechanism cannot be directly applied to single-pass printers

Engineering Contradiction:
Improvetension controlVSAvoidmechanism adaptability
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent adapts the dancer roller mechanism from multi-pass printers to single-pass printers by reconfiguring it for continuous motion. The same basic dancer roller structure serves the dual function of detecting extra length and controlling tension in the single-pass configuration, demonstrating universality. The mechanism is modified to work with continuous material flow rather than intermittent feeding, making it applicable to both printer types.

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

Data Source

PatentEP2927007B1Printing method and printing device for long band-shaped objects
Publication Date: 2020.06.10 YKK CORP
  • EP2927007B1 patent drawingFigure 1
  • EP2927007B1 patent drawingFigure 2
  • EP2927007B1 patent drawingFigure 3

AI summary

The present invention forms a clear image without distortions or color drift at high speed using a single-pass printer (12). The printing device comprises a single-pass printer (12), which is provided with multiple printing units (18) arranged in the conveyance direction of a long band-shaped body (14) that is the printing object and which performs the desired printing (16) on the surface of the long band-shaped object (14). The device is provided with a constant speed drive roller (40) for conveying the long band-shaped object (14) at a specified speed and a constant speed motor (42) for rotating the constant drive roller (40) at a constant speed. The device is provided with tension change-detecting members (26, 30, 33, 52, 54, 57) for detecting the tension of the long band-shaped object (14) at both the upstream side and the downstream side of the printing units (18) in the conveyance direction. The device is provided with speed control rollers (24, 60) for controlling the conveyance speed of the long band-shaped object (14) on the basis of the speed of the long band-shaped object (14) detected at both the upstream side and the downstream side of the printing units (18) in the conveyance direction. A specified printing (16) is performed on the surface of the long band-shaped object (14), which is conveyed at a specified speed facing the printer (12), by keeping the tension of the long band-shaped object (14) constant.