MFC Packaging Material Induction Heat Sealability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional packaging materials for sensitive objects like liquid beverages rely on aluminum for barrier and heat sealing properties, but aluminum poses environmental concerns and is not easily replaceable with renewable materials that maintain these properties effectively.
Innovation Solution
A packaging material comprising a layer of microfibrillated cellulose (MFC) and a continuous aluminum layer, both laminated or extrusion coated with a thermoplastic polymer, allowing for heat sealing by induction with a minimal amount of aluminum, while providing sufficient barrier properties even at high humidity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If aluminum is used for barrier and heat sealing properties, then heat sealability and barrier properties are improved, but environmental compatibility deteriorates
Solution Approach 1:
The invention uses a composite structure combining MFC layer, aluminum layer, and thermoplastic polymer layer. The MFC provides renewable base material, aluminum provides heat sealability and barrier properties, and thermoplastic polymer provides moisture barrier and structural integrity. This composite approach allows reduction of aluminum content while maintaining heat sealability through the synergistic combination of materials.
Solution Approach 2:
The invention changes the physical and chemical parameters of the packaging material by using microfibrillated cellulose with specific surface area and crystallinity characteristics, controlling aluminum content within specific ranges (0.1-20 μm thickness, 1-30 g/m2), and selecting thermoplastic polymers with appropriate melting points. These parameter optimizations enable heat sealability with minimal aluminum while improving environmental compatibility.
2Object-affected harmful factors
If aluminum content is reduced for environmental reasons, then environmental compatibility is improved, but heat sealability deteriorates
Solution Approach 1:
The thermoplastic polymer layer acts as an intermediary between the MFC and aluminum layers, enabling heat transfer and seal formation even with reduced aluminum content. The polymer melts during induction heating, facilitating seal formation, while the aluminum layer provides sufficient conductivity for induction heating at lower thicknesses.
Solution Approach 2:
The invention applies different material properties to different layers: the MFC layer provides renewable base material with specific surface area for induction heating, the aluminum layer provides localized conductivity and barrier properties at minimal thickness, and the thermoplastic polymer layer provides localized meltability for seal formation. This local optimization allows heat sealability with minimal aluminum.
3Object-affected harmful factors
If renewable materials are used to replace aluminum, then environmental compatibility is improved, but barrier properties deteriorate
Solution Approach 1:
The composite structure combines MFC (renewable), aluminum (barrier), and thermoplastic polymer (moisture barrier) to achieve both environmental compatibility and barrier properties. The MFC layer with high surface area provides some barrier properties, while the thermoplastic polymer provides moisture barrier, and the minimal aluminum layer provides oxygen and aroma barrier.
Solution Approach 2:
Different layers provide different barrier functions: MFC provides base structural barrier, thermoplastic polymer provides moisture vapor barrier, and aluminum provides oxygen and aroma barrier. This local specialization of barrier functions achieves comprehensive protection while using minimal aluminum and maximizing renewable content.
4Object-affected harmful factors
If MFC is used as base material, then environmental compatibility is improved, but heat sealability deteriorates
Solution Approach 1:
The thermoplastic polymer layer serves as an intermediary that enables heat sealability on the MFC base material. The polymer melts during induction heating and forms seals, while the MFC provides renewable base material and the aluminum layer provides induction heating conductivity. This intermediary layer allows MFC to function as a heat sealable packaging material.
Solution Approach 2:
The invention optimizes parameters including MFC surface area (5-50 m2/g), aluminum content (1-30 g/m2), and thermoplastic polymer selection to enable heat sealability. The specific parameter ranges ensure sufficient induction heating conductivity from aluminum while the polymer provides meltability for seal formation on the MFC base.
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 material achieves heat sealability by induction and maintains low oxygen transmission rates, making it suitable for liquid packaging, and can be biodegradable or compostable depending on aluminum content, addressing environmental concerns.
Implementation Method 1
the amount of aluminum is sufficient to make the board heat sealable by induction
Implementation Method 2
provides sufficient barrier properties even at high humidity
Data Source
AI summary
The present invention is directed to a packaging material comprising a layer of microfibrillated cellulose (MFC) and an aluminum layer having a thickness of 0.1-20 μm, wherein the layer comprising MFC and/or the aluminum layer has been laminated or extrusion coated on at least one side with a thermoplastic polymer and wherein the amount of aluminum is sufficient to make the packaging material heat sealable by induction. The MFC layer contains at least 60% by weight of microfibrillated cellulose.