Cooling Roller Tension Control for Inkjet Paper Break Prevention
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Solution Overview
Problem
Dew condensation on cooling rollers in inkjet printing apparatuses leads to paper breakage when elongate printing paper transportation is halted, due to the heat of the paper and humidity causing water droplets to adhere to the rollers.
Innovation Solution
A printing apparatus with a controller that adjusts the tension between upstream and downstream drive rollers to create gaps between the paper and cooling rollers, and optionally uses ventilators to blow air and reduce moisture, preventing dew condensation and paper breakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the cooling rollers are used to cool the heated printing paper, then the cooling effect is improved, but dew condensation occurs on the cooling rollers causing paper breakage
Solution Approach 1:
The patent applies preliminary action by reducing the tension of the printing paper before it contacts the cooling rollers. The tension reducing unit lowers the paper tension in advance, creating slack that prevents paper breakage when dew condensation occurs during the cooling process. This proactive measure ensures the paper can withstand the cooling operation without breaking.
Solution Approach 2:
The patent introduces a tension reducing unit as an intermediary between the paper feeding mechanism and the cooling rollers. This intermediary component modifies the paper tension state, creating a buffer that protects the paper from breaking due to dew condensation while still allowing the cooling rollers to perform their cooling function effectively.
2Loss of energy
If the transportation of printing paper is halted after printing, then energy consumption is reduced, but dew condensation continues to occur due to residual heat and humidity
Solution Approach 1:
The patent applies preliminary action by maintaining reduced tension in the paper during the halt period. The tension reducing unit keeps the paper in a slack state even when transportation stops, preventing dew condensation-related breakage during the idle period when residual heat and humidity from the printing process continue to cause condensation on the cooling rollers.
Solution Approach 2:
The patent maintains the tension-reducing action continuously during the halt period. Rather than stopping the tension reduction when transportation halts, the system continues to maintain low tension, ensuring continuous protection against dew condensation throughout the entire halt duration, thereby extending the protective effect beyond the active printing period.
3Object-affected harmful factors
If water droplets from dew condensation adhere to the printing paper, then the paper surface is contaminated, but paper breakage occurs during subsequent transportation
Solution Approach 1:
The patent applies preliminary action by reducing paper tension before water droplets can cause significant damage. The tension reducing unit creates slack in the paper in advance, so when dew condensation occurs and water droplets adhere to the paper surface, the reduced tension prevents the paper from breaking under the stress of the adhered droplets during subsequent transportation.
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
Inhibits paper breakage by reducing contact between the paper and cooling rollers, minimizing dew condensation and ensuring smooth paper transportation resumption.
Implementation Method 1
a plurality of cooling rollers (also called chiller rollers) having a cooling function for cooling the print portions heated by the drying unit
Implementation Method 2
a drying unit for heating and drying print portions of the elongate printing paper printed by the printing unit
Implementation Method 3
a drying unit for heating and drying print portions of the elongate printing paper
Implementation Method 4
dew condensation occurs to the cooling rollers. Especially when the transportation of the elongate printing paper stops after printing is completed, dew condensation tends to be caused by the influence of the heat of the elongate printing paper and humidity due to the ink droplets
Data Source
AI summary
At least one of an upstream drive roller and a downstream drive roller is operated, after printing on web paper and at a time of transportation halt of the web paper, to make a tension value of the web paper between the upstream drive roller and downstream drive roller lower than a tension value at a time of transporting the web paper, so that at least part of contact portions of the web paper in contact with five cooling rollers separate from the five cooling rollers. Consequently, gaps can be produced between the contact portions of the web paper in contact with the five cooling rollers and the five cooling rollers. This can reduce waterdrops due to dew condensation adhering to the web paper. As a result, paper break can be inhibited at a time of starting transportation of the web paper.