Push-Down Mechanism for Rigid Multilayered Substrate Warping
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Solution Overview
Problem
Existing inkjet printing devices face challenges in preventing sudden warping of large rigid multilayered substrates during the drying process, which can lead to collisions with the dryer and damage, due to internal tensions and moisture differences within the substrates, especially when using vacuum transport systems that lack sufficient holding power.
Innovation Solution
The implementation of a push-down mechanism using a flat bar positioned above the transport system, maintained by gantries, which applies mechanical pressure to prevent sudden warping by angling and displacing the flat bar to enhance tension and maintain the substrate's stability during the drying process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If vacuum transport systems are used to support large rigid substrates, then the substrates can be transported and printed on, but the vacuum power is too weak to prevent sudden warping up during drying
Solution Approach 1:
The patent combines the vacuum transport system with a mechanical push-down mechanism consisting of flat bars and gantries. The vacuum system provides baseline adhesion while the mechanical elements provide additional downward force to counteract warping during drying, creating a hybrid support system that overcomes the limitations of vacuum alone.
Solution Approach 2:
The flat bars act as intermediary elements between the substrate and the drying process. These bars apply localized mechanical pressure to specific areas of the substrate, preventing warping without requiring the entire vacuum system to provide sufficient holding force across the entire substrate surface.
2Productivity
If the dryer is positioned close to the substrate (less than 1 cm distance), then drying efficiency is improved, but sudden warping causes collision with the dryer
Solution Approach 1:
The push-down mechanism activates before and during the drying process to prevent warping from occurring in the first place. By applying continuous downward pressure through the flat bars, the system counteracts the internal tensions that would otherwise cause the substrate to warp and collide with the closely positioned dryer.
Solution Approach 2:
The gantry system with flat bars provides dynamic adjustment capability, allowing the mechanical support structure to adapt to substrate movement and warping tendencies during the drying process, maintaining contact and preventing collision with the stationary dryer.
3Temperature
If internal tensions in multilayered substrates are heated during drying, then ink drying is achieved, but the tensions cause sudden unpredictable warping
Solution Approach 1:
The system maintains constant mechanical pressure parameters through the flat bars and gantries during the temperature changes of the drying process. This consistent mechanical constraint counteracts the dimensional changes and warping caused by thermal expansion and moisture evaporation in the multilayered substrate.
Solution Approach 2:
The push-down mechanism is positioned and activated before the drying process begins, establishing mechanical constraints on the substrate before internal tensions from heating and moisture loss can cause warping. This preliminary mechanical support prevents unpredictable shape changes during the drying cycle.
4Ease of manufacture
If moisture differences between layers in corrugated fibreboards are present, then the substrate can be manufactured, but warping occurs during heating
Solution Approach 1:
The flat bars provide localized mechanical pressure at specific contact points on the substrate surface. This distributed local support counteracts the uneven warping forces generated by moisture differences between layers, preventing global shape instability while allowing the substrate to maintain its manufactured structure.
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 solution effectively prevents collisions between the substrate and the dryer, ensuring stable drying and maintaining print quality by immobilizing the substrate, even with large and rigid materials like corrugated fibreboards and plastics, thereby reducing damage and improving the calibration of height settings for uniform drying.
Implementation Method 1
a vacuum transport system for transporting a rigid multilayered substrate (500) in a print direction and for holding the rigid multilayered substrate (500) against a support surface
Implementation Method 2
a dryer (315), attached to a first gantry which is positioned over the transport system and perpendicular to the print direction, for creating a drying zone on the rigid multilayered substrate (500)
Data Source
AI summary
An inkjet printing device includes a transport system for transporting a rigid multilayered substrate in a print direction and a support plane; a dryer, attached to a first gantry which is positioned over the transport system and perpendicular to the print direction, for immobilizing a jetted ink layer in a drying zone; and a push down mechanism for the rigid multilayered substrate against the transport system, arranged at least in the drying zone. The push down mechanism includes a bar which is positioned parallel and elongated to the print direction and mounted parallel to the support plane above the transport system. The bar is maintained on a second and third gantry by a maintainer on each gantry and positioned over the transport system at each side of the first gantry and perpendicular to the print direction. The push down mechanism includes a bender for pushing a portion from the bar at the push down side with an angle towards the transport system in a plane, perpendicular to the support plane and parallel to the print direction.