Foil Transfer Roller Timing to Prevent Sheet Warpage
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Solution Overview
Problem
Conventional foil transfer devices face issues with unnecessary foil film conveyance and impressed marks on sheets due to improper alignment and pressure application of heating and pressure rollers, leading to waste and potential damage.
Innovation Solution
A foil transfer device equipped with a nip/release mechanism and a controller that controls the position of the heating and pressure rollers, allowing for precise alignment and partial foil transfer on a confined surface region, reducing unnecessary conveyance and minimizing sheet damage by restarting sheet conveyance only when rollers are in contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the heating roller and pressure roller are pressed against each other while a sheet is being conveyed, then foil transfer can be performed, but resistance acting on the sheet produces warpage or wrinkling
Solution Approach 1:
The nip/release mechanism performs preliminary action by pressing the heating roller and pressure roller against each other before the sheet reaches the transfer position. The controller stops sheet conveyance before the rollers contact the sheet, then presses the rollers together, and restarts conveyance before the rollers reach the sheet, eliminating resistance-induced warpage while maintaining foil transfer capability.
2Loss of substance
If the heating roller and pressure roller are located apart at startup to reduce useless foil film transport, then foil waste is reduced, but the rollers must be precisely aligned before transfer which increases system complexity
Solution Approach 1:
The nip/release mechanism provides dynamic control over the roller positions, allowing them to be located apart during startup and non-transfer periods, then pressed together precisely when needed. This dynamic positioning reduces foil film waste while the automated controller manages the alignment timing, preventing excessive system complexity.
Solution Approach 2:
The controller uses feedback control to manage the timing of sheet conveyance stopping and restarting in coordination with the roller pressing action. This ensures precise alignment and timing without requiring complex mechanical alignment mechanisms, as the system responds to the sheet position and roller state to optimize both foil waste reduction and alignment precision.
3Shape
If the sheet conveyance is stopped before the rollers are pressed, then warpage is prevented, but the time for foil transfer process increases
Solution Approach 1:
The controller implements a optimized timing sequence that skips unnecessary delays by restarting sheet conveyance before the rollers reach the sheet. This rushes through the critical alignment phase efficiently, minimizing the time the sheet is stopped while still preventing warpage by ensuring the rollers are pressed only when the sheet is properly positioned.
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 configuration reduces foil film waste and minimizes the likelihood of impressed marks on sheets by optimizing the timing of sheet conveyance and roller alignment, effectively preventing warpage and wrinkling.
Implementation Method 1
The heating roller heats the foil film and the sheet being nipped between the heating roller and the pressure roller
Data Source
AI summary
A foil transfer device which transfers foil onto a sheet is disclosed herein. When a nip/release mechanism moves a first roller and starts causing a foil film to be pressed against a confined surface region on a sheet, located apart from a leading edge of the sheet, a controller executes: a first process of causing a conveyor roller to start conveyance of the sheet, while the first roller is positioned in a separate position; a second process of causing the conveyor roller to stop conveyance of the sheet before a foil transfer area reaches a transfer position; a third process of causing the nip/release mechanism to start moving the first roller from the separate position to a nipping position while the conveyance of the sheet is stopped; and a fourth process of causing the conveyor roller to restart conveyance of the sheet before the first roller reaches the nipping position.