Multilayer Film with Thermoplastic Polyester and Starch

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Solution Overview

Problem

Current multilayer films used for packaging, especially for oxygen-sensitive foods, often rely on petrochemical-based plastics and lack eco-friendly and biodegradable alternatives with adequate barrier properties and mechanical strength.

Innovation Solution

A multilayer film structure comprising thermoplastic polyester and thermoplastic starch, which provides excellent barrier properties, mechanical strength, and moisture resistance, while being biodegradable and renewable, with optional additional layers for enhanced performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If petrochemical-based plastics are used for barrier films, then good barrier properties and mechanical strength are achieved, but environmental sustainability and biodegradability are compromised

Engineering Contradiction:
Improvebarrier propertiesVSAvoidenvironmental sustainability
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent employs composite materials by combining thermoplastic polyester (PLA) and thermoplastic starch (TPS) in a multilayer structure. This composite approach allows the film to achieve adequate barrier properties against oxygen and carbon dioxide while being made from renewable, biodegradable materials, thus resolving the contradiction between performance and environmental sustainability.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent utilizes parameter changes by controlling the thickness of individual layers (layer A: 10-1000 μm, layer B: 10-1000 μm) and the overall film thickness (10-2000 μm) to optimize barrier performance. By adjusting these parameters, the film achieves sufficient oxygen permeability (1-50 cm³) while maintaining mechanical strength and biodegradability.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If biodegradable materials are used for packaging films, then environmental sustainability is improved, but barrier properties and mechanical strength deteriorate

Engineering Contradiction:
Improveenvironmental sustainabilityVSAvoidbarrier properties
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent uses composite materials consisting of thermoplastic polyester (PLA) and thermoplastic starch (TPS) in a multilayer configuration. This composite structure enables the biodegradable film to achieve oxygen permeability of 1-50 cm³ and carbon dioxide permeability of 1-30 cm³, demonstrating that renewable materials can provide adequate barrier properties when structured appropriately.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies local quality by assigning different functions to different layers: layer A (thermoplastic polyester) provides mechanical strength and structural integrity, while layer B (thermoplastic starch) enhances biodegradability and contributes to barrier properties. This functional differentiation allows each layer to optimize its specific role, achieving overall performance comparable to petrochemical films.

Inventive Principle:
Principle #3Local quality

3Reliability

If multilayer structure is used to improve barrier properties, then oxygen permeability is reduced, but film complexity increases

Engineering Contradiction:
Improveoxygen permeabilityVSAvoidfilm structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs a relatively simple two-layer composite structure (layer A and layer B) where layer A consists of thermoplastic polyester and layer B consists of thermoplastic starch. This straightforward multilayer design achieves oxygen permeability of 1-50 cm³ without excessive structural complexity, making the film practical for manufacturing and application.

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP2010380B2Multilayered film and method for manufacturing same
Publication Date: 2015.12.30 BIO TEC BIOLOGISCHE NATURVERPACKUNGEN GMBH & CO KG
  • EP2010380B2 patent drawingFigure 1

AI summary

A multilayered film is shown and described that is used in particular for packaging, which comprises at least one first layer A and at least one second layer B, wherein layer A contains thermoplastic polyester and layer B contains thermoplastic starch. The multilayered film according to the invention is characterized by excellent barrier properties, low sensitivity to moisture, and good mechanical strength.