Coreless Paper Roll Winding for Low-Force Spindle Extraction
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Solution Overview
Problem
Existing rewinding machines face issues with complex expandable spindles that are prone to breakage and excessive stress, limiting the reuse of spindles in subsequent cycles, especially when producing coreless paper rolls.
Innovation Solution
A method and apparatus that control the initial winding tension to be lower than the steady-state tension, reducing friction and axial force required for spindle extraction, allowing the use of simple, rigid plastic tubes that can be reused multiple times.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If expandable spindles or elastic deformable spindles are used to enable coreless winding, then the winding function is achieved, but the device complexity increases and the spindle is subjected to excessive stress leading to breakage risk
Solution Approach 1:
The invention changes the winding tension parameter during the winding process. Specifically, the initial winding tension is set lower than the steady-state winding tension. This parameter change reduces the friction between the web and the spindle surface during the critical initial winding phase, thereby reducing the axial extraction force required and enabling the use of simpler, non-expandable, non-elastic spindles that are less prone to breakage.
2Strength
If high winding tension is applied during initial winding, then the web is securely wound on the spindle, but the friction between web and spindle increases requiring excessive axial force for extraction that may damage the spindle
Solution Approach 1:
The invention applies preliminary action by first securing the web to the spindle through initial winding at low tension, then progressively increasing the winding tension to steady-state levels. This preliminary low-tension winding phase establishes the web-spindle connection without creating excessive friction, and subsequent tension increases occur after the web is already securely positioned, avoiding the need for high extraction forces.
3Device complexity
If simple rigid plastic tube spindles are used, then the device cost and complexity are reduced, but the spindles may not be reusable due to potential damage from excessive extraction force
Solution Approach 1:
By changing the winding tension parameter to a lower initial value, the invention reduces the frictional force between the web and the simple rigid plastic tube spindle during winding. This parameter change directly reduces the axial extraction force required, thereby preventing damage to the simple spindle structure and enabling its reuse in subsequent winding cycles without compromising spindle integrity.
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 solution enables easy removal of spindles without damaging them, facilitating their reuse in subsequent cycles while maintaining mechanical integrity.
Implementation Method 1
the friction between the web and the external surface of the spindle is less than a predetermined value and consequently the corresponding axial force required to pull the spindle out of the inside of the roll
Data Source
Figure 1
Figure 1a~1b
Figure 2
AI summary
A method and apparatus for the production of coreless paper rolls, comprising a winding phase on a central spindle (1) of a paper web (2) carried out by a main reel (3), until the formation of a wound paper roll (4), a phase of extraction from the wound roll (4) of the spindle (1) by application of a relative axial extraction force (Fe) between the roll (4) and the spindle (1), where the winding phase includes a first winding phase of a number of web revolutions on the central spindle performed at a first winding tension that is lower than the next winding tension.