Central Tool Sealing for Thermoforming Cycle Time Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for producing hollow bodies using multi-part blow-molding tools require numerous opening and closing movements, leading to increased cycle times and inefficiencies, especially when producing large components like fuel tanks, due to the need for repeated displacement of heavy tool parts.
Innovation Solution
The method involves using a multi-part blow-molding tool with two blow-mold halves and a central tool where the central tool's sealing elements can extend and retract to seal the part-cavities, reducing the need for complete opening and closing movements of the blow-mold halves, and allowing the central tool to handle the sealing and insert placement, thereby minimizing mass movements and cycle time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the blow-mold halves are repeatedly opened and closed to perform sealing and insert placement, then the sealing and insert attachment functions are achieved, but the cycle time increases due to multiple heavy mass movements
Solution Approach 1:
The tool is divided into functionally independent segments: the blow-mold halves remain stationary for sealing, while the central tool with carrier performs insert placement and shell joining operations. This segmentation eliminates the need for repeated opening and closing of the blow-mold halves, reducing cycle time while maintaining sealing reliability.
Solution Approach 2:
The central tool and carrier are designed as movable components that can be dynamically positioned and repositioned within the tool. The carrier can be moved to different locations to place inserts and join shells without requiring the entire blow-mold assembly to move, enabling flexible operation while minimizing mass movements.
2Adaptability or versatility
If the blow-mold halves are displaced for insert attachment, then inserts can be integrated into the hollow body, but the device complexity increases due to additional displacement mechanisms
Solution Approach 1:
The tool architecture separates the sealing function (stationary blow-mold halves) from the insert placement function (movable central tool with carrier). This segmentation allows inserts to be attached without complex displacement of the entire blow-mold assembly, reducing device complexity while maintaining adaptability.
Solution Approach 2:
The central tool acts as an intermediary carrier that holds inserts and positions them onto the preform. This intermediary component enables insert attachment without requiring direct displacement of the blow-mold halves, simplifying the overall tool mechanism while maintaining versatility.
3Ease of manufacture
If the tool uses a simple tool divider for sealing, then the manufacturing cost is reduced, but the ability to guide preforms and control sealing position is limited
Solution Approach 1:
The central tool serves as an intermediary structure that provides both sealing and preform guidance functions. While the tool divider remains simple for sealing, the central tool with its carrier system guides the preform and positions inserts, compensating for the limited guidance capability of the simple tool divider.
4Productivity
If the central tool handles both sealing and insert placement, then the cycle time is reduced by eliminating tool movements, but the central tool complexity increases
Solution Approach 1:
The central tool merges multiple functions (sealing, preform guidance, insert holding, and insert placement) into a single integrated component. This merging eliminates the need for separate mechanisms for each function, reducing the number of tool movements and improving productivity despite the increased functional complexity of the central tool.
Solution Approach 2:
The central tool is designed as a multi-functional component that performs sealing, guidance, and insert placement operations. This universal design consolidates multiple operations into one tool element, improving production cycle speed while the complexity is managed through functional integration rather than multiple separate mechanisms.
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 significantly reduces cycle time by eliminating unnecessary tool movements and simplifying the tool design, enhancing efficiency in producing hollow bodies like fuel tanks by using the central tool for sealing and insert placement, resulting in faster production cycles.
Implementation Method 1
The central tool comprises at least two sealing elements, which are arranged such that they can be extended and retracted on both sides of the central tool
Implementation Method 2
at least two blow-mold halves, which define a mold impression, have part-cavities and can be displaced toward one another and away from one another in the sense of an opening and closing movement
Implementation Method 3
at least one central tool, which is displaceable transversely in relation to the opening and closing movement of the blow-mold halves
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
The invention relates to a method for producing hollow bodies from thermoplastic material by using an at least three-part blow-molding tool with at least two blow-mold halves (1a, 1b), which define a mold impression, have part-cavities (5a, 5b) and can be displaced toward one another and away from one another in the sense of an opening and closing movement, and also with at least one central tool (2), which is displaceable transversely in relation to the opening and closing movement of the blow-mold halves (1a, 1b), the method comprising the extruding or providing and arranging of at least two molten performs (7) of thermoplastic material in web form between the blow-mold halves (1a, 1b) in an opened receiving position, the bringing to bear of the preforms (7) in the part-cavities (5a, 5b) of the blow-mold halves (1a, 1b) and molding of them into shells (10) using sealing elements which are provided on the central tool and are extended from the central tool for the purpose of sealing off the part-cavities before or while the part-cavities are subjected to differential pressure; the joining of at least one insert (9) in at least one shell (10) by using the central tool (2) arranged between the blow- mold halves (la, lb) and the joining of the shells (10) to form the closed hollow body by closing the blow-mold halves (la, lb) while applying clamping force and, if appropriate, the final blow molding of the hollow body.