Roll Unwinder Support Device for High-Quality Flying Splice Cutting
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Solution Overview
Problem
Existing roll unwinders face difficulties in performing high-quality cutting of web materials with varying thicknesses and strengths during on-the-fly roll changes, especially for materials like cardboard and coated papers, due to the challenges of knife penetration and varying cutting path lengths.
Innovation Solution
A support device with a pivoting support element is introduced to stabilize the material web between the unwinding roll and a pressure roller, allowing for adjustable positioning to facilitate clean cutting, regardless of roll diameter and web strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the knife force is increased to cut through thicker and stronger web materials, then the cutting capability is improved, but the web material may avoid the knife movement, changing cutting conditions and reducing cutting quality
Solution Approach 1:
A support device with support elements is introduced as an intermediary between the web material and the cutting environment. These support elements provide stable backing to the web material during cutting, preventing it from moving away from the knife path while allowing sufficient knife force to penetrate through thick and strong materials without compromising cutting quality
2Adaptability or versatility
If the support frame is pivoted to accommodate different roll diameters, then the adaptability to different rolls is improved, but the free path between the roll and cutting point varies, making cutting more difficult
Solution Approach 1:
The support elements are designed to be movable and adjustable rather than fixed. They can be positioned at different locations along the web path and adjusted to accommodate varying roll diameters while maintaining consistent cutting conditions. This dynamic positioning ensures that the support elements remain at optimal distances from the cutting point regardless of which roll size is being used
Solution Approach 2:
The position and configuration of the support elements can be changed as parameters to adapt to different cutting conditions. By adjusting the location and orientation of support elements based on the specific roll diameter and web material properties, consistent cutting quality is maintained across varying operational parameters
3Productivity
If a flying roll change is performed for high grammage and difficult-to-cut materials, then the productivity is improved, but the cutting reliability deteriorates due to varying cutting conditions
Solution Approach 1:
The support device acts as a mediating element that stabilizes the web material during the critical cutting phase of flying roll changes. By providing consistent support and preventing web movement, it ensures reliable cutting even when changing rolls continuously without stopping the web feed, thus maintaining both productivity and cutting reliability
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 reproducible high-quality cutting of diverse web materials, including stronger and thicker materials like cardboard, by ensuring consistent support and pressure during the cutting process, extending the applicability of flying roll changes beyond traditional newspaper or commercial printing materials.
Implementation Method 1
a support device (16), in particular a support element (17), which can be transferred from a rest state to a working state and which can be transferred into a working state supporting the material web B; B' in the area of the web path between the material roll 03; 03' to be unwound and a pressing element 13
Implementation Method 2
a pressing element 13, in particular a pressing roller 13, against which the web B; B' to be severed runs on
Data Source
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AI summary
A roll unwinder (02) for flying-splice roll changeover comprises at least one roll station for holding a first material roll (03), which is to be unwound at the time, and a roll station for holding a second material roll (03'), which is to be unwound once roll changeover has taken place, also comprises a severing tool (14), which can be used to sever a first web (B) unwound from the first material roll (03), and further comprises a pressure-exerting element (13), which can be used to press the first web (B), which is to be unwound at the time, onto the lateral surface of the second material roll (03'), wherein a supporting device (16) is provided, and this supporting device can be transferred from a rest state into an operating state, in which the web (B), which is to be unwound at the time, is supported by the supporting device, at least at the point in time of the severing operation, in the region of the web path at a location which is situated in the web path between the first material roll (03), which is to be unwound, and the location at which the pressure-exerting element (13) interacts with the web (B).