Packaging Lid With Rupture Segments For Steam Venting
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Solution Overview
Problem
Microwave heating of food products in packaging can lead to increased vapor pressure, causing packaging explosions or hot splashes, and existing solutions are not easily openable without tools, are costly, and do not prevent liquid leakage.
Innovation Solution
A packaging tray with a lid featuring two parallel rows of discontinuous rupture segments that act as a valve for steam release and easy opening, made from a mono or multilayer film strip, allowing controlled and centered opening under steam pressure, and manufactured using tools like knife blades or laser cutting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the lid is made tight to prevent liquid leakage, then liquid tightness is improved, but opening difficulty increases and steam pressure builds up causing explosion risk
Solution Approach 1:
The lid incorporates discontinuous rupture segments arranged in parallel rows that segment the lid structure into controlled weak points. These segments allow the lid to maintain overall integrity for liquid containment while providing predetermined locations for controlled rupture under steam pressure, preventing uncontrolled explosion.
Solution Approach 2:
The lid uses material with different mechanical properties in different regions - the rupture segments have reduced strength parameters compared to the rest of the lid structure. This parameter variation allows the lid to be sufficiently strong for liquid tightness while having controlled weak points that rupture at specific pressure thresholds to prevent explosion.
2Object-generated harmful factors
If ventilation openings are provided in the lid, then steam evacuation is improved, but liquid leakage risk increases
Solution Approach 1:
The rupture segments are pre-formed during manufacturing as integral parts of the lid structure, positioned and configured before use. This preliminary action ensures that when steam pressure builds, the rupture occurs at predetermined locations and in a controlled manner, maintaining liquid tightness until the rupture point is reached.
Solution Approach 2:
The lid exhibits local quality variation through the rupture segments - these specific locations have different mechanical properties (reduced strength) compared to the surrounding lid material. This local differentiation allows the lid to maintain overall liquid tightness while having specific localized points designed for controlled steam release.
3Reliability
If a sealing agent strip is added to the lid, then liquid tightness is improved, but manufacturing cost increases
Solution Approach 1:
The rupture segments are integrated directly into the lid structure during the same manufacturing process, combining the lid formation and rupture segment creation into a single operation. This merging eliminates the need for separate sealing agent application steps and additional materials, reducing manufacturing cost while maintaining liquid tightness through the integrated design.
Solution Approach 2:
The lid structure serves multiple functions simultaneously - it provides liquid containment, controlled steam release through rupture segments, and structural support. By integrating the rupture segments into the lid itself rather than adding separate components, the design achieves multi-functionality without increasing manufacturing complexity or cost.
4Ease of operation
If the lid is made easy to open by tearing, then opening ease is improved, but controlled steam release during heating becomes difficult
Solution Approach 1:
The lid is segmented into discrete rupture segments arranged in parallel rows, creating natural tear propagation paths. Once initiated by user action, the tear follows the predetermined segment boundaries, providing both ease of opening and controlled location. The segmentation ensures the tear progresses systematically rather than randomly.
Solution Approach 2:
The rupture segments are positioned asymmetrically with respect to the lid geometry, with specific patterns of spacing and arrangement that guide tear propagation in predetermined directions. This asymmetric arrangement ensures that when the user initiates opening, the tear follows the designed path for easy and controlled opening.
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 safe and easy opening of the packaging without tools, prevents explosions and liquid leakage, and is cost-effective for large-scale manufacturing.
Implementation Method 1
Upon microwave heating, this cut line (a) expands and a small hole forms at the junction between the sealing strip A and the cut line (a). This small orifice (b) then forms a valve allowing the evacuation of the vapor formed inside the packaging container.
Implementation Method 2
The opening of the seal, in particular under the effect of the pressurized steam produced on heating, operates by traction on either side of the discontinuous rows of rupture segments.
Data Source
Figure 1
Figure 2.~7.
Figure 3.~4.
AI summary
The tray (1) has an upper opening (2) covered by a membrane seal (3) that includes upper and lower films. The seal is formed from a packaging material and provides a valve function to evacuate vapor, where the material is in the form of a film strip. The seal has two discontinuous, straight and parallel rows (5a, 5b) of rupture segments (6a, 6b) e.g. slits, located longitudinal with respect to the film strip such that opening of the seal under the effect of pressurized vapor is obtained by traction on both sides of the rows of the rupture segments. Independent claims are also included for the following: (1) a method for fabricating a packaging material (2) a method for series and continuous packaging of food or non food products.