Rigid Blade Ink Coating for Thermal Transfer Printers

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Solution Overview

Problem

Thermal transfer printing systems face challenges in achieving uniform ink coating and consistent print quality due to variations in ink thickness and heating times, leading to patchy or blurred prints.

Innovation Solution

A printing apparatus using a deformable carrier belt and a metal rigid coating blade with a specific Shore Hardness range, combined with a rigid blade that minimizes contact area and controls ink thickness, ensures a uniform ink coating by matching compliance with pressure exerted, allowing for high-speed printing with reduced wear on the ink band.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a rigid blade is used to control ink thickness, then manufacturing precision of ink coating is improved, but the carrier belt may deform excessively under pressure

Engineering Contradiction:
Improveink coating uniformityVSAvoidcarrier belt deformation
Core Design Contradiction:
Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

The patent changes the physical parameter of the carrier belt by specifying a Shore Hardness A range of 50-100, which optimizes the balance between compliance for ink leveling and rigidity to prevent excessive deformation under the rigid blade pressure

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite approach by combining a rigid blade with a compliant carrier belt made of specific materials (rubber, silicone, or thermoplastic elastomer), creating a system where rigid and flexible components work together to achieve both precise ink coating and structural stability

Inventive Principle:
Principle #40Composite materials

2Manufacturing precision

If the carrier belt is made more compliant to level ink, then manufacturing precision is improved, but the ink coating may become overly thick

Engineering Contradiction:
Improveink leveling capabilityVSAvoidink coating thickness
Core Design Contradiction:
Manufacturing precisionVSQuantity of substance

Solution Approach 1:

The patent precisely controls the compliance parameter of the carrier belt through Shore Hardness A specifications (50-100 range), which determines the optimal balance between the belt's ability to deform for ink leveling and its ability to limit ink coating thickness

Inventive Principle:
Principle #35Parameter changes

3Productivity

If printing speed is increased for productivity, then output is improved, but print quality may deteriorate due to insufficient heating time

Engineering Contradiction:
Improveprinting speedVSAvoidprint quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent changes the physical state parameter of the ink from solid to molten by controlling temperature, which reduces ink viscosity and enables rapid transfer to the substrate, allowing high printing speeds while maintaining adequate heating time for quality transfers

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

The system achieves a thin, uniform ink layer, improving print quality and extending the life of the ink band while maintaining high printing speeds, and can operate in any orientation without additional processes for fresh ink coating.

Implementation Method 1

a heating device to heat the hot melt ink on the band

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

a printhead to thermally transfer a portion of hot melt ink from the band to the substrate

Methodology Applied
Scientific EffectThermal transfer: Conduction (thermal)

Implementation Method 3

a rigid blade to control ink thickness of the hot melt ink on the band

Methodology Applied
Scientific EffectPressure: Pressure Increase

Data Source

PatentEP3835070B1Thermal transfer printers for deposition of thin ink layers including a carrier belt and rigid blade
Publication Date: 2023.03.15 DOVER EUROPE SARL
  • EP3835070B1 patent drawingFigure 1
  • EP3835070B1 patent drawingFigure 2
  • EP3835070B1 patent drawingFigure 3A

AI summary

In some embodiments, a printing apparatus comprises a band capable of holding hot melt ink thereon, rollers configured and arranged to hold and transport the band with respect to a substrate, a printhead configured to thermally transfer a portion of hot melt ink from the band to the substrate to print on the substrate, an ink feed device configured to add hot melt ink to the band and to heat the hot melt ink on the band, and a rigid blade configured and arranged to cause hot melt ink to pass between a blade edge of the rigid blade and the band, wherein the rigid blade is shaped to minimize a contact area between the rigid blade and the band while controlling ink thickness of the hot melt ink on the band.