Silicone Concentration Control in Paper Coating
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Solution Overview
Problem
Existing methods for coating printed paper webs with silicone in offset printing face challenges in accurately controlling the silicone concentration, leading to excessive usage, staining, and quality degradation due to manual metering and fluctuating silicone amounts.
Innovation Solution
A method using infrared light with a measuring beam and reference beam to determine the silicone concentration in a solvent/auxiliary mixture through a narrow-band interference filter, allowing precise measurement and regulation of the silicone concentration, and a device with a measuring cell and computer to adjust the mixture accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If manual metering pumps are used to supply silicone/water mixture, then the device complexity is low, but the manufacturing precision of silicone concentration control deteriorates
Solution Approach 1:
The patent replaces manual mechanical metering pumps with an automated dosing system controlled by a computer. The system uses a peristaltic pump driven by a stepper motor, which is controlled electronically based on feedback from infrared measurement of silicone concentration. This substitution of mechanical manual control with an automated electromechanical system resolves the contradiction by providing both automation and precise concentration control.
Solution Approach 2:
The patent implements a feedback control system where the infrared measurement of silicone concentration in the dosing bath continuously provides information to the computer controller. The controller adjusts the peristaltic pump operation based on this feedback to maintain the desired silicone concentration. This closed-loop feedback mechanism enables precise concentration control while automating the dosing process.
2Manufacturing precision
If infrared measurement with narrow-band interference filter is used, then the manufacturing precision of concentration measurement is improved, but the device complexity increases
Solution Approach 1:
The patent introduces a narrow-band interference filter as an intermediary optical element in the measurement path. This filter selectively transmits only the specific infrared wavelength absorbed by silicone, blocking other wavelengths. This intermediary component enables precise silicone concentration measurement by isolating the characteristic absorption band, while the overall system remains manageable through integrated control.
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
Enables reliable and precise control of silicone concentration, preventing over or under-dosing, improving coating quality, and allowing for accurate verification of the silicone-water mixture supplied by the chemical industry, leading to cost savings and enhanced process efficiency.
Implementation Method 1
the coated paper web is irradiated with infrared light. Part of this infrared light is absorbed by the coated paper web, so that conclusions about the thickness of the silicone coating can be drawn from the light attenuation that occurs
Implementation Method 2
determining the concentration of the silicone based on the transmission of the light through the sample
Implementation Method 3
using a narrow-band interference filter to eliminate those that contribute to the transmission spectrum Auxiliaries in the solvent/auxiliary mixture
Data Source
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AI summary
The method involves irradiating a sample of solvent/additive mixture with infrared light by a measuring beam and a reference beam in a measuring cell. Transmission of light through the sample is measured by a measuring optics. Impurities of the optics are eliminated from a transmission spectrum by comparison of transmission values of the measuring beam in a region of characteristic wavelength and the reference beam. Solvents, additives and silicon are supplied tilll concentration of silicon in the solvent/additive mixture corresponds to a predetermined reference value. An independent claim is also included for a device for coating of printed paper webs with silicon.