Roll Unwinder with Movable Splicing for Continuous Ply Changeover
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Solution Overview
Problem
Existing unwinders for thin products wound on a roll face inefficiencies such as manual roll switching, production line downtime, misalignment of spliced plies, and ergonomic challenges, leading to product wastage and safety risks.
Innovation Solution
An unwinder with automatic roll switching capabilities, featuring a splicing assembly and roll-holder assemblies with lateral movement systems, a ply accumulation unit, and alignment devices to facilitate easy roll loading, splicing, and alignment of edges, ensuring seamless transitions without manual intervention.
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 unwinder is divided into two independent roll-holder assemblies (first and second), allowing one roll to be unloaded while the other is being loaded, enabling parallel operations that eliminate production downtime without requiring a completely complex automated system
Solution Approach 2:
The second roll-holder assembly is prepared in advance with a new roll ready for immediate use. The lateral movement system pre-positions rolls, and the splicing assembly is ready to connect plies automatically, eliminating the need for manual intervention and maintaining continuous production
2Productivity
If automatic roll switching is implemented, then productivity improves, but device complexity increases
Solution Approach 1:
The automatic switching function is segmented into independent components: two roll-holder assemblies, a lateral movement system, and a splicing assembly. Each component performs a specific function, making the overall system manageable and maintainable while achieving automatic roll switching
Solution Approach 2:
The splicing assembly automatically connects the trailing edge of the ply from the first roll to the leading edge of the ply from the second roll without manual intervention. The lateral movement system automatically positions rolls, reducing the need for complex automated control mechanisms
3Loss of time
If manual roll loading is used, then ease of operation is maintained, but loss of time increases due to line shutdown
Solution Approach 1:
Rolls are pre-loaded onto the second roll-holder assembly before the first roll is depleted. The lateral movement system pre-positions rolls in the loading zone, and the splicing assembly is ready to connect plies automatically, eliminating the need for manual intervention and maintaining continuous production
Solution Approach 2:
The lateral movement system acts as an intermediary mechanism that automatically transports rolls between the loading zone and unwinding zone, eliminating the need for operators to manually handle heavy rolls in difficult-to-reach locations, thus reducing both time and safety risks
4Ease of operation
If splicing assembly is fixed in unwinding zone, then alignment is maintained, but ease of operation decreases due to limited access
Solution Approach 1:
The splicing assembly is made movable rather than fixed, allowing it to be dynamically repositioned between the unwinding zone for alignment-critical operations and the loading zone for preparation work. This dynamic positioning maintains alignment precision while improving operator accessibility
Solution Approach 2:
The lateral movement system serves as an intermediary that transports the splicing assembly between zones, enabling operators to perform preparation work in the accessible loading zone while maintaining precise alignment capabilities when positioned in the unwinding zone
Data Source
AI summary
Unwinder of a thin ply product wound on a roll, 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 of 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, —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 system for the lateral movement of each of said unwinding rods with respect to said unwinding zone, from said unwinding zone to a loading zone wherein said rolls are outside said winding zone to facilitate loading the rolls into the respective roll-holder assemblies, wherein said splicing assembly can be moved from a working position above the two said roll-holder assemblies in said unwinding zone, to a working position above an extracted roll assembly in the loading zone, to allow preparation for splicing of the leading edge of the ply wound on the spare roll.