Coextrusion Binders for Biodegradable Food Packaging
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Solution Overview
Problem
Biodegradable and biorenewable polymers used in food packaging lack mechanical properties, barrier properties against water and gas, and weldability, requiring the use of non-renewable and non-biodegradable materials in multilayer structures, which increases environmental impact.
Innovation Solution
Development of novel compositions for coextrusion ties using partially or completely biorenewable and biodegradable polymers, grafted with functional monomers, combined with ungrafted compatible polymers and starch, to enhance adhesion and form multilayer structures with reduced environmental impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If biodegradable and biorenewable polymers are used in multilayer structures, then environmental impact is reduced, but mechanical properties, barrier properties, and weldability are insufficient
Solution Approach 1:
The patent employs composite materials by combining biodegradable polymers (PLA, PHA) with non-biodegradable polymers (EVOH, PE) in a multilayer structure. The biodegradable layers provide environmental benefits, while the non-biodegradable layers contribute barrier properties and mechanical strength. This composite approach allows the packaging to achieve both environmental sustainability and functional performance requirements.
2Reliability
If non-renewable and non-biodegradable materials are used to improve mechanical properties and barrier properties, then reliability is improved, but environmental impact increases
Solution Approach 1:
The patent applies local quality by assigning different material properties to different layers of the packaging structure. The outer layers use biodegradable polymers for environmental sustainability, while the intermediate barrier layer uses non-biodegradable EVOH for superior gas and moisture barrier properties. Each layer is optimized for its specific function, allowing the overall structure to meet both environmental and performance requirements.
3Object-affected harmful factors
If biodegradable polymers are used alone, then environmental impact is reduced, but adhesion between layers is insufficient
Solution Approach 1:
The patent uses tie layers composed of polyolefin resins (EVA, EAA, EMA) as intermediaries between the biodegradable polymer layers and the non-biodegradable barrier layer. These tie layers have compatible chemical structures with both types of polymers, enabling effective adhesion and cohesion between layers. The tie layers act as a bridge that overcomes the incompatibility between biodegradable and non-biodegradable materials, ensuring structural integrity.
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 compositions achieve satisfactory adhesion and barrier properties, enabling the formation of multilayer structures suitable for food packaging with a lower environmental impact by utilizing biorenewable and biodegradable materials.
Implementation Method 1
comprising (the total making 100%): 1 to 99% by weight and advantageously 10 to 90% of at least one biorenewable and/or biodegradable polymer (A), grafted with a functional monomer comprising at least one reactive function
Data Source
AI summary
The invention relates to coextrusion binders including renewable and/or biodegradable polymers having good adhesion properties: at least one renewable and/or biodegradable polymer (A) grafted with a functional monomer including at least one reactive function, the grafting ratio being <1% in weight of the grafted polymer (A); at least one non-grafted renewable and/or biodegradable polymer (B) identical to (A) or compatible with (A) optionally a softener (C); and optionally a starch-based material (D). The invention also relates to multilayered structures including the binder of the present invention, in which the layers are preferably made of renewable and/or biodegradable compounds. The multilayered structures are advantageously useful in the field of food packaging.