Dunnage Coiling Tension Control via Movable Dancer Feedback
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Solution Overview
Problem
Existing dunnage conversion systems often result in inconsistent coils of dunnage, leading to potential crushing or tearing of layers, and may form loose coils that are difficult to store and transport, due to uncontrolled tension during the coiling process.
Innovation Solution
A dunnage conversion system that includes a coiler and a movable dancer upstream, controlled by a controller to adjust the coiling speed based on detected tension, which converts slit-sheet stock into a less dense dunnage form by expanding it under tension, thereby preventing crushing and forming a more manageable coil.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the coiling speed is not controlled based on tension, then the coiling process is simple, but the coil consistency deteriorates leading to crushing or tearing of layers
Solution Approach 1:
The system uses a dancer arm to detect sheet stock tension and provides feedback to the controller, which adjusts coiling speed accordingly. This closed-loop feedback mechanism maintains consistent coil quality by dynamically responding to tension variations during the coiling process.
Solution Approach 2:
The coiling speed is made dynamic rather than fixed, allowing the system to adapt to changing tension conditions. The controller continuously adjusts the coiling speed based on real-time dancer arm position, enabling the system to maintain optimal performance under varying operational conditions.
2Volume of moving object
If the sheet stock is expanded under tension, then the dunnage becomes less dense and more voluminous, but the tension control becomes more critical to prevent damage
Solution Approach 1:
The system changes the physical state of the sheet stock by applying tension to expand it from a compact form to a voluminous dunnage structure. The controller manages the tension parameter to achieve the desired expansion while preventing excessive force that could damage the material.
Solution Approach 2:
The dancer arm acts as a cushioning mechanism that absorbs and regulates tension variations before they reach the coiling point. This preemptive tension management protects the sheet stock from sudden force spikes that could cause tearing during the expansion and coiling process.
3Manufacturing precision
If the coiling speed varies to maintain tension control, then the coil quality improves, but the production speed may be reduced
Solution Approach 1:
The feedback control system optimizes the balance between speed and quality by making minimal, targeted adjustments to coiling speed only when tension deviations are detected. This allows the system to maintain high production speeds during normal operation while intervening only when necessary to preserve coil quality.
Solution Approach 2:
The dancer arm and controller system automatically manages tension control without requiring external intervention or complex manual adjustments. The system self-regulates the coiling speed based on real-time conditions, maintaining both efficiency and quality through autonomous operation.
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 produces a consistent and less dense coil of dunnage that is easier to store, transport, and unwind, reducing the risk of damage and improving handling efficiency.
Implementation Method 1
a slit-sheet stock having a plurality of slits configured to expand under tension applied across the slits, such as in a feed direction
Implementation Method 2
The movable dancer may pivot in response to tension of the sheet stock drawn between a supply of the sheet stock and the coiler
Data Source
Figure 1
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AI summary
A dunnage conversion system (20) for making a coil of dunnage (24) from a sheet stock (22, 23) includes a coiler (30), a movable dancer (32) upstream of the coiler (30) and interposed in a path of the sheet stock, and a controller (34) communicatively coupled to each of the coiler (30) and the movable dancer (32). The coiler is configured to wind the sheet stock (22, 23), and the controller is configured to control the speed of the coiler (30) based on the position of the movable dancer (32) to control tension of the sheet stock (22, 23) upstream of the coiler. The sheet stock drawn about the movable dancer (32) may be a slit-sheet stock having a plurality of slits configured to expand under tension applied in a feed direction. The controller (34) may be configured to control expansion of the slit-sheet stock upstream of the coiler allowing conversion of the sheet stock into a coil (24) of relatively less dense dunnage prior to or during winding.