Modified Atmosphere Packaging Tray Sealing with Segmented Gas Circuits
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Solution Overview
Problem
Prior art tray sealers face issues with gas dispersion and prolonged packaging cycles due to inefficient gas injection and evacuation processes, leading to increased costs and complexity in machine design, especially when packaging large or partially filled trays.
Innovation Solution
The method forms a main chamber within the tray using a film and a mechanical interface, with specific holes connected to vacuum and gas supply circuits, allowing for simultaneous vacuum formation and gas injection to rapidly saturate the tray with process gases before sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If air is removed from inside the tray and replaced with modified atmosphere using prior art methods, then the product preservation is improved, but the packaging cycle time is prolonged and gas dispersion increases
Solution Approach 1:
The invention segments the vacuum circuit into two independent circuits: a first circuit connected to holes for evacuating air from the tray, and a second circuit connected to the housing for evacuating air from the housing. This segmentation allows simultaneous evacuation of both the tray and housing, reducing total cycle time while maintaining product preservation quality
Solution Approach 2:
The invention performs preliminary evacuation of the housing air using the second circuit before gas injection. This preliminary action ensures that when modified atmosphere gas is injected, it immediately fills the tray without being diluted by housing air, reducing gas dispersion and shortening the packaging cycle
2Reliability
If process gases are injected into the lower housing to replace air in trays, then the modified atmosphere is achieved, but gas dispersion into the environment increases
Solution Approach 1:
The invention segments gas injection into two independent circuits: a first circuit injecting gas directly into the tray through holes, and a second circuit injecting gas into the housing. This segmentation ensures gas is delivered directly to the product with minimal dispersion into the environment
Solution Approach 2:
The invention uses the housing as an intermediary chamber that is evacuated and then filled with process gas before the tray is sealed. This intermediary approach allows controlled gas transfer from the housing to the tray, minimizing direct gas dispersion to the environment
3Ease of manufacture
If the housing air is not evacuated before gas injection, then the packaging process is simplified, but the modified atmosphere saturation is incomplete
Solution Approach 1:
The invention segments the evacuation function into two independent circuits operating simultaneously: one for the tray and one for the housing. This segmentation maintains process simplicity while ensuring complete atmosphere saturation by removing air from both the tray and housing before gas injection
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 overall packaging cycle time, minimizes gas dispersion, and allows for flexible operation cycles suitable for various product sizes and types, enhancing the efficiency and reliability of the packaging process.
Implementation Method 1
The inner spaces of the two housings are connected to a vacuum source, in order to remove air from inside the trays through the lower housing
Implementation Method 2
means located in the upper housing operate at the correct time by descending and interfering with the film in order to heat-weld it in a sealed way onto the edges of the trays
Data Source
Figure 1~4
Figure 3~8
AI summary
When the opposing housings (1, 8) of the apparatus are closed, they form between them a small main chamber (P) delimited above by the film (H) for covering the tray and below by the tray (V) itself containing the product (M), and laterally by any suitable mechanical interface structure which surrounds the perimeter of said film and connects it to the perimeter of the upper edge (B) of the tray, this interface structure having holes (22) which are suitably distributed, are located outside the perimeter of the tray, and communicate with said main chamber (P). One or more of these holes (22) open(s) on at least one side of the tray and is/are connected to a first circuit (23, 24), while another one or more of said holes (22') open(s) on at least one opposing side of the tray and is/are connected to a second circuit (17) which in turn is connected to the inner chambers of the two housings (1, 8). Means (18, 19, 20) are provided to operate in such a way that, in the step of vacuum formation, both said first circuit (24) and said second circuit (17) are connected to vacuum forming means (21) which are kept active for a sufficient time to eliminate some of the air from the inside of the tray and to act in such a way that said first circuit (24) is connected in the next step or at the correct time to means (25) for supplying the process gases, while said second circuit (17) is closed or remains in communication with the vacuum means (21) to ensure that the process gas entering the tray from said first circuit (22, 24) causes the residual air in the tray to flow out from and/or towards said second circuit (22', 17), thus flushing and saturating the inner volume of the tray, which is subsequently sealed using known steps and means for welding and finally cutting the film (H).