Plastic Lid-Container Assembly for Hazardous Materials
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing lid-container assemblies for hazardous materials fail to maintain a secure seal and mechanical retention, especially under pressure variations and shocks, as they rely on gaskets that wear out or break, and tear-opening systems do not meet UN specifications for effective sealing.
Innovation Solution
A lid-container assembly with a multiple seal system utilizing interference and contact surfaces, eliminating the need for a gasket, featuring snap-fitting circular ribs and tear lines for secure engagement and re-closure, ensuring compliance with UN specifications and facilitating easy assembly and handling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a gasket is used to form a seal between lid and container, then a good seal is obtained initially, but the seal deteriorates over time as the gasket wears, comes out of its seat, or breaks
Solution Approach 1:
The patent removes the gasket component entirely from the sealing system. Instead of using a separate gasket that can wear or fail, the sealing function is integrated directly into the lid and container structures through interference fits and contact surfaces between molded-in features.
Solution Approach 2:
The sealing function is merged with the structural components of the lid and container. The seal is formed by the direct contact between the lid's sealing surface and the container's sealing surface, eliminating the need for a separate gasket component.
2Ease of operation
If a tear-opening system is implemented for easier opening, then ease of operation improves, but the seal quality after closing deteriorates and does not meet UN specifications
Solution Approach 1:
The lid is segmented into multiple functional zones: a tear-opening portion for easy opening, and separate sealing surfaces (with interference fits and contact surfaces) that maintain seal integrity. The tear strip is designed to break away without compromising the remaining sealing structures.
Solution Approach 2:
Different portions of the lid have different properties: the tear-opening area is designed for easy breaking, while the sealing areas have precise interference fits and contact surfaces designed specifically for maintaining hermetic seals under pressure and shock conditions.
3Reliability
If a gasket-based sealing system is used, then sealing is achieved, but the assembly complexity and manufacturing cost increase
Solution Approach 1:
The sealing function is combined with the lid and container molding processes. The sealing surfaces are integrated features of the molded parts themselves, eliminating the need for separate gasket components and their associated assembly steps.
Solution Approach 2:
The lid and container are designed with self-sealing features through interference fits and contact surfaces that automatically engage when the lid is placed on the container, without requiring additional sealing components or complex assembly procedures.
4Ease of manufacture
If traditional lid designs are used, then manufacturing is straightforward, but the mold removal and automatic handle assembly become difficult
Solution Approach 1:
The handle is pre-assembled or pre-positioned during the molding process itself. The lid design incorporates features that allow automatic handle assembly to occur as part of the molding operation, eliminating separate assembly steps and improving productivity.
Data Source
Figure 1
Figure 2~3
Figure 4~6
AI summary
A lid-container assembly (1, 2) made of plastic material suitable for the transportation and storage of hazardous materials in conformity to the UN standard; the container (1) comprises a bottom (20) and a substantially cylindrical or cone trunk side wall (3) having an upper edge (4) that bounds an access opening; the container (1) is provided with a first external annular strip (5) provided with a first circular rib (6) and with at least one second circular rib (7) for snap fitting of the lid (2); the lid (2) comprises a central part (8) and a peripheral wall (9) that conforms to the side wall (3) of the container (1); the lid (2) further comprises a second external annular strip (10) that releasably engages the corresponding external annular strip (5) of the container (1). The external annular strip (10) of the lid (2) has an upper annular element (11) that connects to the peripheral wall (9) by an upturned U-shaped upper annular channel (12), and comprises a lower annular element (15) configured for being inserted into a lower annular channel (18) in the form of a U pointing upwards, and an intermediate annular element (13) for tear opening; the lower annular element (15) of the external strip (10) of the lid (2) is configured with a circular rib (17) of the lid (2) that engages a corresponding internal rib (19) to the lower annular channel (18) of the external strip (5) of the container (1). The lid-container assembly (1, 2) further comprises a first (21) interference sealing zone between opposite surfaces of the side wall (3) of the container (1) and of the peripheral wall (9) of the lid (2); a second (22) contact sealing zone between the upper edge (4) of the side wall (3) of the container (1) and the interior of the upper annular channel (12); at least one third (23) contact sealing zone between opposite engaging ribs of the external annular strips (5, 10) of the lid (2) and of the container (1).