Press Curve Control via Real-Time Density Profiling
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Solution Overview
Problem
In the production of wood-based panels, existing continuously operating presses face challenges in maintaining the desired raw density profile due to delays in obtaining actual density data, leading to suboptimal panel quality and increased scrap rates, especially when wood material properties change, and rely heavily on operator expertise and continuous monitoring.
Innovation Solution
A continuously operating press equipped with two endlessly rotating steel belts, temperature-controlled heating plates, and a control system that includes a measuring device for real-time raw density profiling, an analysis device to adjust the press curve based on deviations from the target profile, and the option for semi-automatic or automatic operation to optimize press settings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If laboratory sections are taken for density profile determination, then quality control is possible, but significant delay occurs in obtaining actual density data
Solution Approach 1:
The patent replaces the mechanical/laboratory-based density measurement system with a non-contact optical measurement system. The optical sensor detects density profile by measuring light absorption or reflection properties of the pressed material as it passes through the press, eliminating the need for physical sampling and laboratory analysis.
Solution Approach 2:
The patent introduces an optical sensor as an intermediary device between the press and the measurement system. This sensor continuously monitors the density profile of the material strand in real-time as it exits the press, providing immediate feedback without requiring physical contact or post-processing.
2Adaptability or versatility
If manual adjustment of press settings is performed, then operator experience can optimize density profile, but long delay occurs in reacting to changing process parameters
Solution Approach 1:
The patent implements a closed-loop feedback system where the optical sensor continuously measures the actual density profile and feeds this information back to the control system. The control system automatically compares the measured profile with the target profile and adjusts press settings in real-time, eliminating the delay inherent in manual monitoring and adjustment.
Solution Approach 2:
The control system performs automatic self-adjustment of press parameters based on real-time density measurements. The system monitors its own performance and makes corrective adjustments without requiring external human intervention, enabling rapid response to process variations.
3Productivity
If continuous monitoring of density profile is implemented, then real-time control is possible, but device complexity increases
Solution Approach 1:
The patent replaces complex mechanical measurement systems with a non-contact optical sensing system. This substitution simplifies the overall device architecture by eliminating mechanical contact points, sample handling mechanisms, and laboratory equipment while achieving continuous real-time measurement capability.
4Manufacturing precision
If press operator continuously monitors and adjusts settings, then quality can be maintained, but operator workload increases significantly
Solution Approach 1:
The control system automatically performs the monitoring and adjustment functions that would otherwise require continuous operator attention. The system self-regulates press settings based on real-time feedback from the optical sensor, maintaining quality while eliminating the need for constant manual intervention.
Solution Approach 2:
The automated feedback loop continuously monitors density profile and automatically adjusts press parameters, replacing the need for operator monitoring and manual adjustment. This maintains manufacturing precision while significantly reducing operator workload.
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 enables improved quality control, reduced rejects, and increased efficiency by allowing for real-time adjustments to the press settings, reducing the workload on operators and enabling better mechanical properties in the panels, leading to material savings and improved economic efficiency.
Implementation Method 1
Such measuring devices operate non-contact using X-rays. An X-ray source transmits X-rays at an angle through the sheet strand, and detectors arranged on the opposite side of the sheet strand record the transmitted radiation and the radiation scattered by the sheet strand to thereby determine the density of the sheet strand.
Implementation Method 2
the pressing force is transferred to the pressing and heating platens by hydraulic actuators, particularly hydraulic pressure cylinders
Data Source
Figure 1~2
Figure 3~4
Figure 5~6d
AI summary
A continuously operating press (1) comprises: two continuously revolving steel belts (3), which form a press gap for pressing the product to be pressed (8), a rolling bearing support arranged between the steel belts (3), a frame (2) for taking up the pressing forces, which are introduced via hydraulic work cylinders (4) in order to press the product to be pressed (8) so as to form a material plate (11) and in order to adjust the press gap, and a control system (20) for providing open-loop and/or closed-loop control of the operation of the press (1). A measurement device (12) for detecting the raw density profile of the material plate (11) is also provided, and the control system (20) is designed to control the work cylinders (4) in accordance with a pressing curve by means of open-loop and/or closed-loop control, the control system (20) also comprising an analysis apparatus (23), which receives the measurement values detected by the measurement device (12), analyses the detected raw density profile as an actual raw density profile in respect of deviations from a target raw density profile, and on the basis of the analysis determines changes to be made on the pressing curve in order to approximate or match the actual raw density profile to the target raw density profile. The control system (20) can adjust (1591) the pressing curve automatically according to the changes determined by the analysis device (23).