Thermoformed Container Rolled Rim for Rigidity and Lid Fit
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Solution Overview
Problem
Existing thermoformed containers made of polymeric materials lack structural integrity in the sidewall and rim, leading to deflection, spillage, and unsanitary squared-off edges, which are uncomfortable and prone to germ collection.
Innovation Solution
A method for forming a container with a rolled rim using a thermoformable sheet of polymeric material, involving thermoforming, coining to create a controlled inside diameter, and rolling the rim structure to enhance rigidity and stability, utilizing polymeric materials like PET and polypropylene.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a thin-walled thermoformed container is made using conventional methods, then the container is inexpensive and easy to manufacture, but the sidewall and rim lack structural integrity and bend easily
Solution Approach 1:
The patent applies preliminary action by forming a rim structure with specific geometry (flange and skirt portions) before the final rolling operation. The flange extends outwardly and the skirt extends downwardly, creating a pre-configured structure that enables subsequent rolling to produce the desired rolled rim configuration. This preliminary structuring ensures structural integrity is built into the design before final formation.
Solution Approach 2:
The patent applies curvature by rolling the rim structure to form a rounded, curved rolled rim instead of leaving it as a squared-off edge. The rolling process creates a smooth, curved surface that eliminates sharp edges while maintaining structural strength. This curved configuration provides both aesthetic appeal and functional benefits including improved grip and eliminated germ collection points.
2Ease of manufacture
If a squared-off rim is provided on the container, then the manufacturing process is simple, but the sharp edges are uncomfortable and germs may collect under the rim
Solution Approach 1:
The patent applies curvature by rolling the rim structure to form a rounded, curved rolled rim instead of leaving it as a squared-off edge. The rolling process creates a smooth, curved surface that eliminates sharp edges while maintaining structural strength. This curved configuration provides both aesthetic appeal and functional benefits including improved grip and eliminated germ collection points.
Solution Approach 2:
The patent applies preliminary action by forming a rim structure with specific geometry (flange and skirt portions) before the final rolling operation. The flange extends outwardly and the skirt extends downwardly, creating a pre-configured structure that enables subsequent rolling to produce the desired rolled rim configuration. This preliminary structuring ensures structural integrity is built into the design before final formation.
3Weight of moving object
If polymeric material is used for the container, then the container is lightweight and recyclable, but the material becomes soft during thermoforming making rim rolling difficult
Solution Approach 1:
The patent applies preliminary action by forming a rim structure with specific geometry (flange and skirt portions) before the final rolling operation. The flange extends outwardly and the skirt extends downwardly, creating a pre-configured structure that enables subsequent rolling to produce the desired rolled rim configuration. This preliminary structuring ensures structural integrity is built into the design before final formation.
Solution Approach 2:
The patent applies parameter changes by controlling the thickness relationship between the flange and skirt portions. The flange is formed with a greater thickness than the skirt portion, creating an optimized geometric configuration that enables successful rolling of polymeric materials. This thickness parameter optimization allows the soft polymeric material to be properly formed during the rolling process while maintaining structural 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 provides a rigid, sanitary, and durable rolled rim that improves lid fit and prevents deflection, enhancing the structural integrity and hygiene of polymeric containers.
Implementation Method 1
The sheet or web is heated to a temperature suitable for thermoforming—such as, for example, in a range from approximately 110° C. to about 200° C. for the above-mentioned materials
Implementation Method 2
A mold cavity is used to impart a particular shape to define the thin-walled container as the plastic sheet or web is drawn into the mold using vacuum pressure on one side of the sheet or web
Implementation Method 3
the process proceeds under applied positive and/or negative air pressure conditions
Data Source
AI summary
Method of forming a container having a rolled rim, including providing a thermoformable sheet, and thermoforming the sheet to form a hollow body. The hollow body has an open first end and an opposite closed second end with a sidewall extending between the first end and the second end, and a rim structure formed at the first end of the hollow body. The rim structure includes an inner wall portion, a flange, and a skirt. The method further includes coining an upper section of the inner wall portion of the rim to form a controlled inner diameter, and rolling the rim structure to form a rigid rolled rim along an outer diameter of the open first end of the hollow body, the skirt extending toward the sidewall after being rolled.