Deep-Drawing Tray Forming with Score Lines and Lateral Tool Spacing
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Solution Overview
Problem
Existing deep-drawing methods for forming trays from sheet materials often result in tearing and irregular wrinkling, particularly in materials with limited plasticity, leading to aesthetically unsatisfactory and leak-prone packaging solutions, and require separate moulding tools for varying tray sizes and thicknesses.
Innovation Solution
A method and apparatus that utilize score lines transversally on the sheet material, with the male and female moulding tools laterally distanced to allow free forming of the tray side walls, and adjustable spacer plates or screws to accommodate varying depths and material thicknesses, preventing constriction and enabling controlled wrinkling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional deep-drawing methods are used with closely fitted moulding tools, then the tray shape can be precisely formed, but the sheet material suffers from tearing and irregular wrinkling
Solution Approach 1:
The patent introduces score lines as intermediary elements that predetermine wrinkle locations. These score lines act as mediators between the moulding tools and the sheet material, guiding the material to wrinkle in controlled, aesthetically pleasing patterns rather than irregularly, thereby resolving the contradiction between shape precision and material integrity
Solution Approach 2:
The patent changes the physical state of the sheet material by pre-creasing it along score lines before deep-drawing. This parameter change (from flat to pre-creased) allows the material to accommodate the forming process with controlled wrinkling, preventing tearing while maintaining tray shape precision
2Device complexity
If fixed moulding tools are used for deep-drawing, then the process is simple, but the tools cannot adapt to varying tray sizes and material thicknesses
Solution Approach 1:
The patent makes the moulding tools dynamic and adjustable rather than fixed. The depth of the female moulding tool cavity can be modified by changing inserts or adjusting the tool position, allowing the same tool to accommodate different tray depths and sizes, thereby resolving the contradiction between tool simplicity and versatility
Solution Approach 2:
The patent designs the moulding tools with universal capabilities to handle multiple tray sizes, shapes, and material thicknesses through adjustable features. This multi-functionality allows a single set of tools to perform various deep-drawing operations, eliminating the need for dedicated tools for each tray specification
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 the occurrence of tearing and irregular wrinkling, allows for aesthetically pleasing tray formation, and enables adaptable moulding tools for different tray sizes and material thicknesses without the need for tool changes, improving the quality and versatility of deep-drawn trays.
Implementation Method 1
Wrinkling is a handicap of materials, particularly paper, board and metals, which have limited plasticity and adaptability to shaping in the process
Data Source
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AI summary
The invention relates to a method and anapparatus for deep-drawing a tray(1) froma blank ofsheet material(2).The blank is provided with score lines, which determine the location of wrinkles formed in the process.The apparatuscomprises a female moulding tool(3), which comprises a cavity(7)for forming the tray bot- tom outwardly,a male moulding tool(4), which comprises a plunger(11)for form- ing the tray bottom inwardly, the plunger being movable with respect to the cavity for forming the tray, andclamps(6, 15)with an interface for holding the sheet ma- terial and forming a tray rim flange. According to the inventionby laterally distanc- ingat least one ofthe moulding tools (3, 4) from the sheet material leeway is pro- vided for free forming so that wrinklingof the tray side wallsis achieved in a con- trolled manner.Spacer plates (13) may be positioned behind the plunger (11), to adjust its position in relation to thecavity (7) of thefemale moulding tool (3). The cavity may have a separate bottom plate(8)and spacer plates(9)therebelow, or screw means may be provided foradjusting the distance ofthe bottom of the cavi- ty fromthe clamp interfaceand thereby varying the depth of the tray.