Multilayer Biodegradable Film for Mechanical Strength and Transparency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing biodegradable packaging films struggle to balance high mechanical properties, biodegradability, and optical transparency, often compromising on one or more of these characteristics due to the heterogeneous nature of their compositions.
Innovation Solution
A multilayer film structure comprising at least one layer of aliphatic and/or aliphatic-aromatic polyester or polyvinyl alcohol, and another layer with specific polymer compositions, including polyester, polyhydroxyalkanoate, and inorganic filler, which provides high mechanical strength, rapid biodegradability, and optical transparency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If heterogeneous compositions are used to achieve high mechanical properties and biodegradability, then mechanical strength and biodegradability are improved, but optical transparency deteriorates
Solution Approach 1:
The film is divided into multiple homogeneous layers, each with specific composition and function. Layer A contains aliphatic/aromatic polyester for mechanical strength, while Layer B contains aliphatic polyester with controlled composition for biodegradability and optical properties. This segmentation allows each layer to be optimized independently, resolving the contradiction between mechanical strength and transparency.
Solution Approach 2:
The invention uses a composite multilayer structure combining different polyester materials with complementary properties. Layer A provides mechanical strength through aromatic polyester content (35-70% by moles), while Layer B provides biodegradability and transparency through controlled aliphatic polyester composition. The composite structure achieves all three properties simultaneously.
2Strength
If heterogeneous compositions are used to achieve high mechanical properties, then mechanical strength is improved, but biodegradability deteriorates
Solution Approach 1:
The film structure separates mechanical function (Layer A with aromatic polyester) from biodegradation function (Layer B with aliphatic polyester and polyhydroxyalkanoate). This segmentation allows Layer B to be specifically optimized for biodegradability through controlled composition without compromising the mechanical properties provided by Layer A.
Solution Approach 2:
The composite multilayer structure combines materials with different degradation rates and mechanical properties. Layer B's specific composition (aliphatic polyester with 35-70% aromatic dicarboxylic acid by moles, plus polyhydroxyalkanoate) ensures rapid biodegradability while Layer A maintains mechanical strength, achieving both properties in the final product.
3Illumination intensity
If non-biodegradable materials are used to achieve high optical transparency, then optical properties are improved, but biodegradability deteriorates
Solution Approach 1:
Layer B uses a specific composite composition of aliphatic polyester with controlled aromatic dicarboxylic acid content (35-70% by moles) combined with polyhydroxyalkanoate (1-40% by weight) and inorganic fillers (0-15% by weight). This composite achieves optical transparency comparable to HDPE while maintaining rapid biodegradability, eliminating the need for non-biodegradable transparent materials.
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 multilayer film achieves mechanical strength sufficient to support weights of 3-4 kg, rapid biodegradability under composting conditions, and optical properties comparable to non-biodegradable materials like HDPE, with transparency above 90% and haze below 65%, suitable for food packaging.
Implementation Method 1
a multilayer film comprising at least one first layer A and at least one second layer B, wherein the layer A and layer B are different from each other
Data Source
AI summary
This invention relates to a multilayer biodegradable film which is particularly suitable for the manufacture of packaging and is also characterised by appreciable optical transparency properties in addition to high level mechanical properties.