Glass-Ceramic Plate Surface Control for Inkjet Print Quality

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Solution Overview

Problem

Existing glass and glass-ceramic plates used in cooking appliances face challenges in achieving high-quality print images, particularly in non-contact printing methods like inkjet printing, due to issues with surface roughness and flatness, which affect print quality and consistency.

Innovation Solution

The plates are designed with a flatness of less than 0.1% of the lateral dimension and a mean surface roughness of less than 0.5 µm with a standard deviation of less than 0.1 µm, featuring coatings on different sub-regions with controlled raggedness, allowing for precise inkjet printing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If inkjet printing is used to print on glass or glass ceramic plates, then production flexibility and batch size variability are improved, but print quality and edge sharpness deteriorate due to surface roughness and flatness issues

Engineering Contradiction:
Improveproduction flexibilityVSAvoidprint quality
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent applies local quality by specifying that only certain regions of the glass or glass ceramic plate need to have improved surface properties (flatness and roughness) where the coating will be applied. The plate may have different surface qualities in different areas, with the coated regions having Rz < 0.5 μm and flatness < 0.1% while other areas can have standard surface characteristics. This allows selective surface treatment to optimize print quality without compromising production flexibility.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the surface parameters of the glass or glass ceramic plate by controlling and optimizing surface roughness (Rz < 0.5 μm) and flatness (< 0.1% of lateral dimension). These parameter changes create optimal conditions for inkjet printing, enabling high print quality while maintaining the flexibility of inkjet printing processes. The controlled surface parameters ensure homogeneous coating application and reduced raggedness.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If screen printing is used to print on glass or glass ceramic plates, then print quality and edge sharpness are improved, but production flexibility and batch size variability deteriorate

Engineering Contradiction:
Improveprint qualityVSAvoidproduction flexibility
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The patent applies preliminary action by pre-treating or selecting glass or glass ceramic plates with specific surface properties (flatness < 0.1% and roughness Rz < 0.5 μm) before the printing process. This preliminary preparation of the substrate ensures that subsequent inkjet printing achieves print quality comparable to screen printing, while retaining the flexibility advantages of inkjet technology for varying batch sizes and designs.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If the surface roughness of the plate is reduced to improve print quality, then coating homogeneity is improved, but surface strength and resistance to mechanical damage may deteriorate

Engineering Contradiction:
Improvecoating homogeneityVSAvoidsurface strength
Core Design Contradiction:
Manufacturing precisionVSStrength

Solution Approach 1:

The patent changes the surface parameters by controlling roughness to Rz < 0.5 μm while maintaining adequate surface strength. This optimized parameter range provides sufficient smoothness for homogeneous coating application and high print quality, while retaining enough mechanical strength for cooking applications. The balance is achieved through precise control of surface treatment parameters.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent may employ composite approaches by combining glass or glass ceramic materials with specific surface treatments or coatings that provide both smooth surfaces for printing and enhanced mechanical strength. The composite structure ensures both coating homogeneity and surface durability are achieved simultaneously.

Inventive Principle:
Principle #40Composite materials

4Manufacturing precision

If the flatness of the plate is improved to enhance print quality, then coating uniformity is improved, but manufacturing complexity and processing difficulty increase

Engineering Contradiction:
Improveprint qualityVSAvoidmanufacturing complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies local quality by requiring high flatness (< 0.1% of lateral dimension) only in the regions where coating will be applied, rather than throughout the entire plate. This localized requirement reduces manufacturing complexity while still achieving the necessary print quality and coating uniformity in the critical areas.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the flatness parameter to < 0.1% of lateral dimension, which provides optimal conditions for inkjet printing and homogeneous coating application. This parameter change balances print quality requirements with manufacturing feasibility, avoiding excessive flatness requirements that would unduly complicate production while still achieving excellent coating uniformity.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4317094B1Plate comprising glass or glass ceramic, method for the production thereof and use thereof
Publication Date: 2026.04.15 SCHOTT AG
  • EP4317094B1 patent drawingFigure 1a~1c
  • EP4317094B1 patent drawingFigure 2
  • EP4317094B1 patent drawingFigure 3

AI summary

The invention relates generally to plates comprising glass or glass-ceramic, in particular those which are at least partially covered with a coating, a method for producing such plates and their use.