Rotary Screen Printing Device with Multi-Blade Ink Control
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Solution Overview
Problem
Existing screen printing technologies face challenges in achieving reproducible and precise printing on differently dimensioned panes at high and rapid rates, particularly in the automotive glazing industry, where ink residues can cause ghost images and blurred patterns due to accumulation in screen meshes, and current processes are not cost-effective due to slow cycle times.
Innovation Solution
A screen printing device featuring a rotating hollow cylindrical screen stencil with a third doctor blade for defined ink pre-filling, a first doctor blade for ink application, and a second doctor blade for ink removal, along with an ink supply and removal system that includes a supply channel and ink collection, allowing for independent rotation and ink recirculation, enabling faster printing speeds and reducing ink accumulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional screen printing processes are used, then printing can be performed on glass panes, but the printing speed is limited to 3-4 m/min which is too slow for cost-effective automotive glazing production
Solution Approach 1:
The invention transitions from conventional flatbed or slow rotary screen printing to a high-speed rotary screen printing system where the screen stencil and substrate move synchronously on a conveyor. This dynamic configuration enables printing speeds of 15-20 m/min (up to 30 m/min), dramatically improving productivity while maintaining print quality through continuous motion and precise registration.
Solution Approach 2:
The rotary screen printing process enables continuous printing operation where the screen stencil rotates continuously alongside the substrate conveyor. This eliminates the stop-start nature of conventional printing, allowing uninterrupted ink transfer and achieving sustained high-speed production necessary for cost-effective automotive glazing manufacturing.
2Manufacturing precision
If conventional screen printing is used, then ink can be applied through the screen mesh, but ink residues accumulate in the meshes causing ghost images and blurred patterns
Solution Approach 1:
The invention introduces a doctor blade system that actively removes ink residues from the screen mesh surface after each printing cycle. The doctor blade scrapes excess ink and accumulated residues off the screen, preventing ghost images and blurred patterns, thereby maintaining consistent print quality and reliability throughout continuous high-speed operation.
Solution Approach 2:
The doctor blade acts as an intermediary element between the screen stencil and the printing process. It mediates the ink transfer by controlling the ink layer thickness and removing residues, ensuring clean, precise ink patterns are transferred to the substrate without contamination from accumulated ink in the mesh.
3Productivity
If faster printing speeds are implemented, then productivity increases, but ink accumulation and smearing problems worsen
Solution Approach 1:
The ink supply device in the rotary screen printing system performs preliminary action by precisely controlling and delivering the exact amount of ink needed to the screen mesh before the printing cycle begins. This pre-metering of ink prevents excessive ink accumulation that would cause smearing at high speeds, while ensuring sufficient ink is available for complete coverage, thereby maintaining print quality at production rates of 15-20 m/min or higher.
Data Source
AI summary
Screen printing device for applying an ink, having at least: a) a conveyor belt, b) a rotating hollow cylindrical screen stencil arranged above the conveyor belt with a circumferential screen and a rotating ink removal cylinder arranged adjacent the screen stencil, wherein: c) inside the screen stencil an ink supply device, a first doctor blade adjacent the conveyor belt, a second doctor blade adjacent the ink removal cylinder, and a third doctor blade, which is arranged upstream of the first doctor blade in the running direction of the conveyor belt and/or the rotational direction of the screen stencil are provided.