Paper Feeder Air Flow Control for Electrostatic Sheet Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Friction feeders in paper processing machines often cause electrostatic charging of sheets, leading to sticking issues and reliability problems, especially with colored paper, and existing solutions like vacuum feeders are more expensive and sensitive.
Innovation Solution
A method and device that uses controlled air flow to separate sheets, adjusting air flow cycles to impart a pulsating movement to the top sheet, mitigating electrostatic charging by determining the sheet's vertical position and adjusting air flow accordingly, with a higher flow in one part of the cycle and a lower flow in another, using a fan arrangement and sensor to control the process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a friction feeder is used to pick sheets from a stack, then the feeder is robust and reliable in operation, but the top sheet becomes electrostatically charged causing sheets to stick together
Solution Approach 1:
The patent applies periodic action by cycling the air flow between higher and lower flow rates. During continuous operation, the flow of air is controlled in cycles with one part of the cycle (preferably the first part) with a higher flow of air and one part of the cycle (preferably the second part) with a lower flow of air. This periodic variation mitigates electrostatic charging while maintaining sheet separation.
Solution Approach 2:
The patent uses pneumatic principles by introducing a flow of air between the top sheet and the stack. The air flow serves to separate the uppermost sheet from the rest of the stack without requiring vacuum mechanisms, thus maintaining the robustness of friction feeders while eliminating electrostatic charging problems.
2Reliability
If air flow is increased to separate sheets more effectively, then sheet separation improves, but energy consumption increases
Solution Approach 1:
The patent implements periodic action by cycling air flow between higher and lower flow rates. During continuous operation, the flow of air is controlled in cycles with one part of the cycle (preferably the first part) with a higher flow of air and one part of the cycle (preferably the second part) with a lower flow of air. This periodic variation maintains effective sheet separation while reducing overall energy consumption compared to continuous high flow.
Solution Approach 2:
The patent applies dynamics by making the air flow rate variable rather than constant. The system dynamically adjusts air flow between higher and lower levels in cycles, adapting the energy input to the actual separation needs at different moments during operation.
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
The solution effectively reduces electrostatic charging and improves the reliability of sheet separation, allowing for precise control of sheet positioning and minimizing the risk of sheets sticking together, enhancing the performance of friction feeders without the high cost and sensitivity issues of vacuum feeders.
Implementation Method 1
providing a flow of air for separating an uppermost sheet of paper from the rest of the stack of papers
Implementation Method 2
By imparting the uppermost sheet of paper a pulsating movement up and down, the problems associated with electrostatic charging are mitigated
Implementation Method 3
determining the vertical position of the uppermost sheet of paper
Data Source
Figure 1
Figure 2
Figure 3~8
AI summary
A method for feeding sheets of paper comprises the following steps: providing a stack of papers (12) on a storage surface (14) of a paper feeding device (10); providing a flow of air for separating an uppermost sheet of paper (12a) from the rest of the stack of papers; determining the vertical position of the uppermost sheet of paper; adjusting the flow of air in dependence on the determined vertical position of the uppermost sheet of paper; and repeating the steps of determining the vertical position of the uppermost sheet of paper and adjusting the flow of air in dependence on the determined vertical position of the uppermost sheet of paper. During continuous operation, the flow of air is controlled in cycles with one part of the cycle, preferably the first part of the cycle, with a higher flow of air, and one part of the cycle, preferably the second part of the cycle, with a lower flow of air. By imparting the uppermost sheet of paper a pulsating movement up and down, the problems associated with electrostatic charging are mitigated.