Segmented Mandrel Air Chambers for Coreless Roll Removal
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Solution Overview
Problem
Conventional perforated mandrels for winding coreless rolls of stretchable plastic film face challenges in controlling air flow rate and reducing air consumption during roll removal, leading to pressure drops and increased energy usage.
Innovation Solution
A mandrel with separate fore and rear air chambers, connected to a pressurized air source via a duct system with selectively actuable control valves, allows for controlled air supply during roll winding and removal, with air chambers disconnected sequentially to minimize air consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single air chamber is used in the mandrel, then the structure is simple, but air consumption increases and pressure drops occur during roll removal
Solution Approach 1:
The mandrel air chamber is divided into multiple separate air chambers (first air chamber and second air chamber) along the axial direction. Each chamber can be independently controlled by its own control valve, allowing selective disconnection from the pressurized air source. This segmentation reduces the total air consumption during roll removal while maintaining structural functionality.
2Reliability
If pressurized air is supplied continuously during roll removal, then air cushion is maintained, but air consumption and energy usage increase
Solution Approach 1:
The control system operates control valves to periodically connect and disconnect air chambers from the pressurized air source during the roll removal process. This periodic action maintains the air cushion when needed while reducing air consumption during transitions, optimizing both reliability and energy efficiency.
3Device complexity
If a single air chamber is used, then the mandrel structure is simpler, but pressure drops occur during roll removal
Solution Approach 1:
The air chamber is segmented into multiple independent chambers along the axial direction, each equipped with its own control valve. This allows selective disconnection of individual chambers from the pressurized air source during roll removal, maintaining stable air pressure in active chambers while reducing overall air consumption.
4Reliability
If pressurized air flow is increased to prevent roll implosion, then roll stability is improved, but air consumption increases
Solution Approach 1:
Different air chambers are selectively activated based on the local requirements during roll removal. The control system connects specific chambers to the pressurized air source only when and where needed, providing localized air cushion support to prevent roll implosion while minimizing overall air consumption.
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
This approach reduces air consumption by approximately 50% compared to single-chamber mandrels, maintaining a homogeneous air cushion and minimizing pressure losses, thereby enhancing the efficiency of the winding and removal process.
Implementation Method 1
use is made of a pressurised air flow for causing some internal turns of the rolls to radially expand
Implementation Method 2
pressurised air escapes from through holes of the mandrel in order to reduce the frictional forces between contact surfaces
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
One or a plurality of coreless rolls of a stretchable plastic film are wound up on a mandrel (10) having a tubular body; the mandrel (10) comprises at least a fore air chamber (14) and a rear air chamber (15) axially aligned, wherein the peripheral wall (11) of the mandrel (10) comprises a perforated zone (16, 17) in correspondence of each air chamber (14, 15). One or a plurality of coreless rolls (B1, B2) of stretchable plastic film are wound up on the mandrel (10) at said perforated zones (16, 17) and air chambers (14, 15); the roll or rolls (B1, B2) are removed by pushing said roll or rolls along the mandrel (10), by supplying pressurised air initially into all air chambers (14, 15) during a first removal step of the roll or the rolls (B1, B2) and selectively disconnecting each chamber (14, 15) from the pressurized air source, starting from the rear air chamber (15) to the fore air chamber (14) at overcoming of each air chamber (14, 15) by said roll or rolls (B1, B2).