Automatic Unwinder Splicing With Ply Edge Alignment
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Solution Overview
Problem
Existing unwinders for thin products wound on a roll face inefficiencies such as manual roll switching that causes production line downtime, misalignment of plies leading to product wastage, and complex roll insertion processes, posing ergonomic and safety challenges.
Innovation Solution
An unwinder with automatic roll switching featuring an automatic guide device for maintaining axial position and aligning side edges, a system for lateral movement of unwinding rods, and a splicing assembly that facilitates easy roll loading and splicing, including sensors for edge detection and correction, and a ply accumulation unit with adjustable deviator rollers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If manual roll switching is used, then the structure is simple, but production line downtime increases and productivity decreases
Solution Approach 1:
The system performs preliminary actions by accumulating product on the production line before the roll runs out. The accumulation unit stores a buffer amount of product, allowing the unwinder to switch rolls without stopping the production line. This resolves the contradiction by preparing advance (product accumulation) to enable seamless roll transition.
Solution Approach 2:
The patent introduces an intermediary accumulation unit that acts as a buffer between the unwinder and the production line. This intermediary component decouples the roll switching operation from the production line operation, allowing roll changes without line downtime while managing the complexity through a dedicated buffer mechanism.
2Loss of substance
If manual roll switching is used, then the device complexity is low, but product wastage increases due to line stoppage
Solution Approach 1:
The accumulation unit performs preliminary accumulation of product before the roll is fully unwound. This buffer stock prevents the need to stop the line and discard product during roll switching, thereby reducing product wastage while introducing a controlled complexity through the accumulation mechanism.
3Productivity
If automatic roll switching is implemented, then productivity improves, but misalignment of plies occurs leading to product defects
Solution Approach 1:
The system employs feedback mechanisms with sensors that detect the position and alignment of plies during automatic roll switching. The control system uses this feedback information to adjust and correct alignment, ensuring precise ply joining while maintaining high-speed automatic operation, thus resolving the contradiction between speed and precision.
Solution Approach 2:
The patent replaces manual mechanical alignment operations with an automated control system that uses sensors and actuators. This substitution enables precise alignment control through electronic feedback loops, maintaining manufacturing precision while achieving high-speed automatic roll switching.
4Productivity
If roll accumulation unit is added, then line continuity is maintained, but device complexity and operational difficulty increase
Solution Approach 1:
The accumulation unit is designed to perform self-service functions where the system automatically manages product accumulation and roll transition without requiring complex manual intervention. The automated control system handles the coordination between accumulation, roll switching, and line feeding, simplifying operation while maintaining continuity.
5Productivity
If automatic splicing system is used, then productivity improves, but ergonomics deteriorate due to complex setup requirements
Solution Approach 1:
The patent repositions the accumulation unit and splicing mechanism in a vertical dimension above the roll holder assembly. This dimensional change allows operators to access and perform setup operations from a convenient working height, improving ergonomics while maintaining the automated splicing functionality that enhances productivity.
Data Source
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AI summary
Unwinder of a thin ply product wound on a roll, of the type with automatic switching of the unwinding roll with a spare roll, said unwinder comprising - a first roll-holder assembly equipped with a first unwinding rod for a respective roll, on which the roll is adapted to be supported, and which has an axis of rotation transversal to the direction of movement of the ply unwound from the roll, - a second roll-holder assembly equipped with a second unwinding rod for a respective roll, on which the roll is adapted to be supported, said second rod being parallel to said first unwinding rod of the first roll-holder assembly, said second roll-holder assembly facing said first roll-holder assembly in an unwinding zone, wherein of said two roll-holder assemblies, one assembly holds the unwinding roll and the other assembly holds the spare roll to be switched, - a ply splicing assembly placed above said first and second facing roll-holder assemblies, - a ply accumulation unit to allow automatic switching between a roll being unwound in one said roll-holder assembly and a spare roll provided in the other roll-holder assembly, - a transversal position correction system for the side edges of the plies on the rolls present in said roll-holder assemblies.