Adjustable Suction Roll Release Timing for High-Speed Paper Folding
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Solution Overview
Problem
Existing paper converting machines with suction rolls face limitations in processing paper at speeds exceeding 150-200 m/min, leading to inaccurate folding, jams, and reduced productivity due to paper adhering beyond the release point, especially with varying paper weights.
Innovation Solution
A suction roll with a displacement device that adjusts the catching and releasing points of paper adherence on its surface by altering the angular positions of vacuum distribution, allowing for flexible operation at varying speeds and paper weights.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the suction roll is designed for high-speed operation, then productivity increases, but the paper remains adhered to the roll beyond the releasing point causing jams and quality issues
Solution Approach 1:
The suction roll system transitions from fixed suction chambers to movable suction chambers that can dynamically adjust their position along the roll. This allows the releasing point to be dynamically adjusted based on operating speed and paper characteristics, enabling the system to maintain reliable paper release even at high advancement speeds where inertial effects would normally cause the paper to remain adhered beyond the intended releasing point.
2Adaptability or versatility
If the suction roll uses fixed suction chambers, then device complexity is reduced, but adaptability to different paper weights and speeds is limited
Solution Approach 1:
The suction roll is designed with multiple suction chambers that can be selectively activated and positioned along the roll length. This universal design allows the same suction roll structure to handle different paper weights (from light to heavy) and different operating speeds by simply adjusting which suction chambers are active and their positioning, rather than requiring different rolls for different applications.
Solution Approach 2:
The system incorporates movable suction chambers that can be repositioned along the roll, providing dynamic adaptability to varying operational requirements. This mechanical dynamic capability allows the system to adjust to different paper weights and speeds without increasing fundamental structural complexity, as the movement mechanism integrates into the existing roll design.
3Productivity
If the suction roll operates at speeds above 200 m/min, then productivity increases, but manufacturing precision deteriorates due to unwanted folds and imprecise paper movement
Solution Approach 1:
By enabling dynamic adjustment of the releasing point position through movable suction chambers, the system can compensate for inertial effects that occur at high speeds. This ensures that paper is released at the precise moment and location needed for accurate folding operations, maintaining manufacturing precision even when operating above 200 m/min where inertial effects would normally cause timing and positioning errors.
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 high-speed paper processing without compromising product quality by anticipating or postponing the adherence and release instants, preventing wrinkles and ensuring precise folding or interfolding.
Implementation Method 1
a device for generating a determined vacuum degree, normally a vacuum pump, is provided that is pneumatically connected to the inner part of the suction roll
Implementation Method 2
a vacuum distribution device configured to selectively put into pneumatic communication said suction chamber with at least one row of suction holes of said plurality at determined angular positions of said tubular body
Data Source
AI summary
A suction roll of a web, or sheet, of paper, includes a tubular body that rotates about a longitudinal rotation axis. External and internal lateral surfaces of the suction roll pneumatically communicate with each other through suction holes. The roll includes a suction chamber pneumatically connected to a vacuum generation device for generating a predetermined vacuum degree. A vacuum distribution device selectively puts into pneumatic communication the suction chamber with at least one row of suction holes, at determined angular positions of the tubular body and causes the processed sheet or web of paper to be sucked, and to adhere at a corresponding portion of the external lateral surface arranged between a catching point and a releasing point having determined angular positions. A displacement device moves the vacuum distribution device to change the angular position of the catching or releasing point of the web or sheet of paper.