Thermoformed Capsule Sealing Element to Eliminate Elastomeric Washers
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Solution Overview
Problem
Existing capsules for beverages in dispensing machines face hygiene issues due to wear and deterioration of elastomeric washers, which come into contact with the product and fluid, and are either costly or require precise manufacturing for optimal sealing.
Innovation Solution
A capsule with a thermoformable plastic casing and a sealing element featuring a protrusion that deforms to create a seal within the dispensing machine, eliminating the need for specific sealing means and allowing adaptation to different machine models.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an elastomeric washer is used for sealing between the capsule and housing, then a hydraulic seal is ensured, but the washer is subject to wear and deterioration and comes into contact with product and fluid without proper washing
Solution Approach 1:
The sealing function is extracted from the reusable housing/washer component and transferred to the disposable capsule itself. The capsule's flange edge is designed with an integrated sealing structure that directly contacts the housing, eliminating the need for a separate elastomeric washer that accumulates contamination.
Solution Approach 2:
The capsule with its integrated sealing flange edge is designed as a disposable single-use component. After one use, the entire capsule including the sealing surface is discarded, preventing the accumulation of product residue and fluid contamination that would occur with reusable washers.
2Reliability
If a sealing element made of silicone rubber different from the casing material is used, then sealing is achieved, but the capsule becomes costly and difficult to fix by thermowelding
Solution Approach 1:
The flange edge is made from the same thermoplastic material as the capsule body, allowing the entire capsule to be manufactured in one piece using injection molding or thermoforming. This homogeneous material composition enables thermowelding and other plastic joining methods while eliminating the need for separate sealing elements.
Solution Approach 2:
The sealing function is merged into the structural design of the flange edge itself rather than being a separate component. The flange edge's geometry and material properties are designed to provide sealing through its interaction with the housing, combining structural support and sealing functions in one element.
3Ease of manufacture
If concentric circumferential ridges are used as sealing element made of the same material as casing, then manufacturing is simplified, but very precise manufacturing by injection moulding is required to ensure optimum seal
Solution Approach 1:
The flange edge is designed with elastic or yieldable material properties that allow it to deform under compression when the capsule is inserted into the housing. This dynamic deformation capability compensates for minor variations in manufacturing tolerances, ensuring reliable sealing without requiring extremely precise molding.
Solution Approach 2:
The sealing mechanism relies on changing the physical state of the flange edge material through compression, transforming it from a rigid structural element to a deformable sealing element. This parameter change allows the same material to provide both structural support and sealing function with relaxed manufacturing tolerances.
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
Ensures an optimal seal during dispensing without additional sealing components, maintaining hygiene and reducing production costs while being easily manufacturable through thermoforming.
Implementation Method 1
a sealing element (9) that comprises at least one protrusion (10), which defines a further cavity (11) open in a direction facing said base wall (3)
Implementation Method 2
The protrusion (10) has a deformable structure, which ensures elasticity and deformability of the edge (7)
Implementation Method 3
The sheet of plastic material and the capsule are thermoformable
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
A capsule for beverages comprises a casing (2) in turn comprising a base wall (3) and a side wall (4) defining a cavity (5) suitable for containing an initial product (P) to be combined with a fluid (F) to obtain an end product and also an edge (7) extending from the side wall (4). The capsule further comprises a cover element (8) fixed to the edge (7) to close the cavity (5) hermetically, which is perforable by extracting means of a dispensing machine (60) in which said capsule is usable. The casing (2) is made by forming a sheet of thermoformable plastic material and the edge (7) comprises a sealing element (9) comprising at least one protrusion (10) facing the base wall (3) which is also obtainable by forming the sheet material that defines at least one further cavity (11) which opens upwards in a direction opposite said base wall (3) and has a bottom with a thickness (19) comprised between 0.15 mm and 0.90 mm. The cover element 8 has dimensions so as to cover only partially the edge (7).