Laminated Packaging Material with High-Melting Polymer Layer
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Solution Overview
Problem
Existing laminated packaging materials for liquid foods face challenges in maintaining gas-tightness and package integrity, particularly around openings, due to delamination issues caused by thermal and mechanical stresses during manufacturing and handling, which can lead to impaired gas-tightness and difficulties in opening the package.
Innovation Solution
Incorporating a thermo-mechanically stable polymer layer with a melting point higher than 150°C, composed of ethylene vinyl alcohol copolymer (EVOH) and polyamide (PA), between the aluminium foil and the bulk material layer, along with intermediate thermoplastic polymer layers, to enhance adhesion and support the aluminium foil, thereby improving package integrity and oxygen barrier properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional thermoplastic polymer layers are used in the laminated packaging material, then the packaging can be manufactured with standard materials and processes, but the layers delaminate under thermal and mechanical stresses during manufacturing and handling, compromising gas-tightness and package integrity
Solution Approach 1:
The patent changes the thermal parameter of the polymer layer by selecting materials with melting points above 150°C (such as polyamides and ethylene vinyl alcohol copolymer) instead of conventional lower-melting-point thermoplastics. This parameter change ensures the bonding layers remain stable and maintain adhesion during high-temperature sterilization and handling processes, preventing delamination while preserving package integrity
Solution Approach 2:
The patent employs composite material structures by combining multiple polymer layers with different properties: a bonding layer of polyamide or ethylene vinyl alcohol copolymer for thermal stability and adhesion, combined with heat-sealable thermoplastic layers. This composite approach allows the packaging to withstand thermal and mechanical stresses without delamination while maintaining gas-tightness through the aluminium foil barrier
2Reliability
If the aluminium foil is adequately supported to maintain gas-tightness, then oxygen barrier properties are improved, but the package becomes more difficult to open due to increased structural rigidity
Solution Approach 1:
The patent applies local quality by providing aluminium foil support only in specific regions where gas-tightness is critical (such as the body of the package and sealing areas), while leaving opening areas with different structural characteristics. This allows the aluminium foil to be adequately supported for maintaining oxygen barrier properties in storage, while enabling easier opening at designated locations without requiring excessive force
3Reliability
If a thermo-mechanically stable polymer layer with melting point above 150°C is incorporated, then adhesion and support for aluminium foil are enhanced, but the device complexity increases due to additional layer requirements
Solution Approach 1:
The patent achieves multi-functionality by selecting polymer materials that simultaneously provide multiple functions: the bonding layer of polyamide or ethylene vinyl alcohol copolymer with melting point above 150°C serves as both the adhesive bonding layer and the thermo-mechanically stable support layer for the aluminium foil. This eliminates the need for separate stabilizing layers, reducing overall structure complexity while maintaining strong adhesion and foil support
Solution Approach 2:
The patent uses composite material design where the bonding layer itself is constructed from high-melting-point polymers (polyamide or ethylene vinyl alcohol copolymer) that inherently provide both adhesion and thermo-mechanical stability. This composite approach consolidates multiple functions into a single layer, avoiding the need for additional complex layers while ensuring aluminium foil support and strong bonding
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 improved package integrity and oxygen barrier properties, allowing for better support of the aluminium foil and maintaining the package's gas-tightness and nutritional value during storage, while also facilitating easier opening of the package.
Implementation Method 1
a thermo-mechanically stable polymer layer, of a polymer composition having a melting point higher than 150°C
Implementation Method 2
an aluminium metal foil... bonded to the bulk layer by at least one intermediate layer of thermoplastics
Implementation Method 3
the aluminium metal foil, the inner- and outermost thermoplastic polymer layers... are sealed to each other within the regions of the holes to form a membrane... improving package integrity and oxygen barrier properties
Data Source
Figure 1a~1c
Figure 2a~2b
Figure 3a~3b
AI summary
The present invention relates to a laminated cellulose-based liquid food packaging material, comprising a cellulose-based bulk material layer, having through-going holes, openings or slits, an aluminium metal foil and outer layers of thermoplastic polymers. The invention further relates to the method for manufacturing the laminated packaging material and to a packaging container for liquid food packaging, comprising the laminated packaging material.