Single-Web Unwind Splicing With Dual Brake Tension Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing unwind machines in converting lines lack efficient and automated control systems for managing web unwinding and splicing processes, particularly in handling multiple webs and ensuring consistent tension and seamless transitions during roll changes.
Innovation Solution
A control system with integrated brake assemblies and actuators, including lower and upper brake arms, pivot arm actuators, and festoon actuators, is implemented to automate and sequence operations, ensuring precise tension control and smooth roll transitions through a converting line, utilizing sensors and a human-machine interface for real-time adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If manual adjustment of drag brake is used to control roll rotation during unwinding, then device complexity is reduced, but manufacturing precision and tension control consistency deteriorate
Solution Approach 1:
The patent replaces manual mechanical brake adjustment with an automated electronic control system that uses sensors to detect web tension and automatically adjusts brake assembly positioning and drag brake application. This substitution of manual mechanical control with an automated sensing and actuating system resolves the contradiction by maintaining simple mechanical interfaces while achieving precise, consistent tension control through electronic feedback.
Solution Approach 2:
The patent implements a feedback control system where sensors continuously monitor web tension and roll rotation parameters, and this information is fed back to automatically adjust brake assembly positions and drag brake force. This closed-loop feedback mechanism ensures consistent tension control without requiring complex manual adjustment procedures, thereby resolving the contradiction between device simplicity and control precision.
2Manufacturing precision
If automated control system with sensors and actuators is implemented, then manufacturing precision and tension control are improved, but device complexity increases
Solution Approach 1:
The patent designs the brake assemblies and actuators to serve multiple functions: they control roll rotation, maintain web tension, enable seamless splicing operations, and provide positioning for roll changes. By making these components multi-functional, the system achieves high manufacturing precision without proportionally increasing device complexity, as the same hardware performs multiple critical tasks.
Solution Approach 2:
The patent combines the brake control, tension monitoring, and roll positioning functions into an integrated control system where sensors, actuators, and control logic work as a unified ensemble. This merging of functions into a coordinated system reduces the overall complexity compared to having separate independent systems for each function, while still achieving high precision tension control.
3Productivity
If seamless splicing and roll transitions are achieved through automated control, then productivity is improved, but device complexity increases
Solution Approach 1:
The patent implements preliminary positioning and preparation actions before splicing operations occur. The automated control system pre-positions the brake assemblies, pre-tensions the web, and pre-aligns rolls before the actual splicing event. This preliminary action enables seamless transitions that improve productivity without requiring overly complex real-time control during the critical splicing moment.
Solution Approach 2:
The patent maintains continuous web tension and continuous roll rotation control throughout the splicing operation. The automated control system ensures that the web remains under consistent tension and that rolls continue to rotate without interruption or speed variation during splicing. This continuity of useful action enables seamless splicing that improves productivity while keeping the control mechanism relatively simple by avoiding stop-start operations.
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
The system enhances operational efficiency by maintaining consistent web tension, facilitating seamless splicing and unwinding, and reducing operational complexity, making it suitable for both new and existing converting line configurations.
Implementation Method 1
a brake assembly (70) configured to engage the roll of web material to control rotation of the roll
Data Source
AI summary
A converting line has a unwind machine with a load station assembly and a vertical movement assembly. The load station assembly rotatably supports a roll as the web is unwound during a first portion of an unwind cycle. The vertical movement assembly rotatably supports the roll during movement between lowered and raised positions during a second portion of the unwind cycle. A lower brake assembly controls rotation of the roll in the load station assembly, and an upper brake assembly controls rotation of the roll with the roll in the vertical movement assembly. With the roll rotatably supported in the load station assembly, the converting line control generates signals for the lower brake assembly to control an unwind rotation rate of the roll. With the roll rotatably supported by the vertical movement assembly, the control generates signals for the upper brake assembly to control the unwind rotation rate.