Slitter-Winder Joint Removal for Thick Fiber Web Roll Changes
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Solution Overview
Problem
Existing slitter-winders face challenges in efficiently processing thick fiber webs, particularly in the joining and unwinding processes, leading to prolonged parent roll changes and vibration issues in customer rolls due to unsuitable joint methods.
Innovation Solution
A slitter-winder design with two unwinders and a joining device forming form-fitting joints, combined with a cutting device to remove joint parts, and a reject handling system to manage excess material, allowing simultaneous end joining and set change, reducing unwinding time and ensuring joints are not present in finished customer rolls.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single unwinder is used in the slitter-winder, then the device complexity is reduced, but the productivity decreases due to slow parent roll changes taking up to ten minutes
Solution Approach 1:
The unwinding function is segmented into two separate unwinders (first unwinder and second unwinder) that can operate independently. This allows the system to switch between unwinders during operation, enabling continuous production while one unwinder is being changed. The segmentation of the unwinding task resolves the contradiction by allowing rapid parent roll changes without stopping the entire production line.
2Ease of manufacture
If adhesive tapes are used to join fiber web ends, then the joining process is simple, but the quality deteriorates as tapes peel off fibers from the thick fiber web surface
Solution Approach 1:
The harmful adhesive tape joining method is completely removed from the system. Instead, the patent uses a form-fitting joint method where the end of one parent roll is mechanically fitted into the beginning of the next parent roll without adhesive tapes. This extraction of the harmful element resolves the contradiction by eliminating fiber peeling while maintaining a simple joining process.
Solution Approach 2:
The joining method transitions from adhesive-based (chemical parameter) to form-fitting mechanical joint (geometric parameter). By changing the fundamental parameter of how joining is achieved, the system eliminates the fiber peeling problem associated with adhesive tapes while maintaining ease of manufacture through the simple form-fitting mechanism.
3Strength
If form-fitting joints are used to join parent rolls, then the joining strength is improved, but the harmful factors increase as joints become thicker and cause vibration problems in customer rolls
Solution Approach 1:
The system performs preliminary action by detecting the joint location in advance and proactively removing it before the joint can cause vibration problems in customer rolls. The joint detection and removal mechanisms are activated beforehand to prevent the harmful effect of vibrations, thus resolving the contradiction between having strong joints and avoiding vibration issues.
Solution Approach 2:
The potentially harmful thick joint is converted into a benefit by using its presence as a detectable signal. The joint detection system uses the joint's unique characteristics (thickness, density) to identify its location, then the removal system converts this harmful element into a benefit by eliminating it before it can cause vibrations in the final product.
4Productivity
If the slitter-winder operates at high speed, then the productivity increases, but the difficulty of operation increases due to insufficient time to manually remove joints
Solution Approach 1:
The system performs self-service by automatically detecting and removing joints without manual intervention. The joint detection system and removal mechanisms operate autonomously, allowing the slitter-winder to maintain high running speeds while joints are handled automatically. This eliminates the need for manual joint removal and resolves the contradiction between high speed operation and ease of operation.
Data Source
AI summary
A slitter-winder for fiber webs has an unwinding section (10), a slitting section (20) and a winding section (30) and is configured to unwind, slit and wind a thick fiber web having a basic weight of at least 200 g/m2 to customer rolls (33). The unwinding section (10) has a first unwinder (11) and a second unwinder (12) for unwinding the thick fiber web from a parent roll of full-width thick fiber web (W11, W12), and a joining device (16, 17) for joining a beginning end of a thick fiber web (W11) coming from a parent roll in the first unwinder to an end of a thick fiber web (W12) coming from a parent roll in the second unwinder by forming a joint (J). The winding section (30) has a cutting device (35) for cutting and removing joint part(s) of the thick fiber web from the winding section (30).