Ink Fountain Key Correction for Web Offset Blanket Cleaning
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Solution Overview
Problem
In web offset printing, switching between print jobs results in excessive ink supply adjustments and test printing, leading to increased preparation time, workload, material waste, and decreased production efficiency due to residual ink film thickness distributions and solvent effects on the blanket.
Innovation Solution
An ink supply method that involves cleaning the blanket, calculating corrected ink fountain key openings, and forming a corrected ink film thickness distribution on the ink roller group by adjusting the ink fountain key openings and performing a predetermined number of feed operations with the ink ductor roller to prevent lightly printed products and material waste.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the ink fountain key opening ratios are adjusted to values corresponding to the image of the printing plate of the next print job, then the ink supply amount is changed to match the new print job requirements, but the residual ink film thickness distribution from the preceding print job remains on the ink roller group, requiring excessive ink supply adjustments and test printing
Solution Approach 1:
The patent applies preliminary action by performing blanket cleaning immediately after the preceding print job ends, before the ink fountain key opening ratios are adjusted for the next print job. This preliminary cleaning removes residual ink and solvent effects from the blanket, preventing them from interfering with the ink film thickness distribution formation for the next print job. As a result, when the ink supply amount is adjusted to match the new print job requirements, the adjustment is more effective and requires fewer test printing iterations, thereby reducing preparation time.
2Manufacturing precision
If test printing is performed to adjust the ink supply amount and obtain a satisfactory color tone, then the ink film thickness distribution is optimized for the printing plate, but printing materials are wasted and working load increases
Solution Approach 1:
The patent performs blanket cleaning as a preliminary action before final ink supply adjustment and printing. This preliminary cleaning ensures that the blanket is free from residual ink and solvent effects that would otherwise require multiple test printing passes to compensate for. By eliminating these interfering factors in advance, the ink film thickness distribution can be optimized with minimal or no test printing, thereby reducing printing material waste and working load.
Solution Approach 2:
The patent converts the potentially harmful effect of residual ink and solvent on the blanket into a beneficial outcome by systematically cleaning the blanket. This cleaning process transforms the problematic residual substances into removable contaminants, allowing the ink film thickness distribution to be established cleanly without the need for excessive test printing to correct errors caused by residual interference.
3Stability of the object's composition
If the ink film thickness distribution for the preceding print job remains on the ink roller group, then the ink supply system maintains the previous configuration, but excessive ink supply amount adjustment and test printing are needed to achieve the correct color tone for the next print job
Solution Approach 1:
The patent applies preliminary action by cleaning the blanket immediately after the preceding print job, which prevents the residual ink film thickness distribution from interfering with the next print job's ink supply adjustments. This preliminary cleaning ensures that when the ink supply amount is adjusted for the new print job, the adjustment is accurate and requires minimal test printing, thereby maintaining production efficiency.
Data Source
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AI summary
After the end of a preceding print job, a printing press is stopped, and ink form rollers (6-1 to 6-4) of an ink roller group (6) are thrown off. After that, a printing plate (7) is exchanged with a printing plate (7') of a next print job, and a blanket (91) mounted on a blanket cylinder (9) is cleaned. The opening amounts of ink fountain keys (4-1 to 4-n) corresponding to the image of the printing plate (7') of the next print job are obtained. The obtained opening amounts of the ink fountain keys (4-1 to 4-n) are corrected by correction values of the opening amounts of the ink fountain keys (4-1 to 4-n) considering the influence of cleaning of the blanket (91) to obtain corrected opening amounts. In a state in which the opening amounts of the ink fountain keys (4-1 to 4-n) have been set to the corrected opening amounts, a corrected ink film thickness distribution corresponding to the image of the printing plate (7') of the next print job is formed on the ink roller group (6).