Thermoforming Web Transport Assembly for Stable Sheet Alignment
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Solution Overview
Problem
Existing pin chain transport systems in thermoforming machines are inefficient in maintaining sheet stability and precision during the thermoforming process, leading to issues such as vibration and misalignment.
Innovation Solution
A web transport assembly with gripper chains and parallel rail structures, featuring spring-loaded gripper mechanisms and angled hubs, ensures stable and precise movement of flexible sheet material through thermoforming stations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pin chain transport system is used to move plastic sheet, then the sheet can be transported through the thermoforming machine, but the sheet experiences vibration and misalignment leading to poor stability and precision
Solution Approach 1:
The continuous chain is segmented into discrete gripper links that independently engage with the sheet. Each gripper link acts as an independent element that can be precisely positioned, eliminating the vibration and misalignment issues of traditional pin chains while maintaining reliable sheet transport through the thermoforming process.
2Manufacturing precision
If traditional pin chains are used for sheet transport, then the structure is simple, but the sheet experiences vibration and misalignment during processing
Solution Approach 1:
The gripper links are designed with movable gripping elements that can dynamically adjust their position and engagement force with the sheet. This dynamic capability allows precise sheet positioning while the modular structure keeps the overall system manageable in complexity, resolving the trade-off between precision and structural simplicity.
3Productivity
If pin chains puncture through the plastic sheet to pull it forward, then the sheet can be moved to the forming station, but the sheet stability is compromised leading to vibration
Solution Approach 1:
The harmful puncturing action is extracted and replaced with a non-puncturing gripping mechanism. The gripper links engage with the sheet surface without penetrating it, eliminating the source of vibration while maintaining efficient sheet transport through the thermoforming machine via controlled gripping and release cycles.
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
Enhances sheet stability and precision, reducing vibrations and misalignment, thereby improving the efficiency and quality of blister formation and trimming processes.
Implementation Method 1
The gripper links have a gripper mechanism that is configured to clamp a side of the flexible sheet material. In some embodiments, a stop device that is actuatable to either allow or prevent movement of the plastic sheet into the gripper chains may be provided.
Implementation Method 2
At least one of the hubs includes a driven sprocket having a plurality of teeth engaging the associated gripper chain. For example, the upstream hub may be an idler and the downstream hub may be driven.
Data Source
AI summary
A web transport assembly for moving flexible sheet material in a manufacturing process. The web transport assembly comprises first and second gripper chains spaced apart from one another to define a path of travel of the flexible sheet material, each of the gripper chains having a plurality of saddle links and a plurality of gripper links. First and second parallel rail structures are respectively aligned with the first and second gripper chains. In addition, upstream and downstream hubs are associated with each of the first and second gripper chains to define a continuous loop about which the associated gripper chain extends. At least one of the hubs includes a driven sprocket having a plurality of teeth engaging the associated gripper chain. The saddle links have a pair of spaced apart extension portions defining a spaced in which an associated one of the rails is received. The gripper links have a gripper mechanism that is configured to clamp a side of the flexible sheet material.