Methods of making reduced weight multilayer polymeric articles

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Solution Overview

Problem

There is a need to reduce the weight of multilayer polymeric articles while maintaining their desired properties for applications such as refrigeration insulation liners, where existing methods do not effectively balance weight reduction with impact and tensile strength requirements.

Innovation Solution

The method involves creating multilayer polymeric articles with at least one foamed polymeric layer, using styrenic polymers and copolymers, and incorporating a foaming agent to reduce density, combined with solid polymer layers to maintain structural integrity and desired properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If the weight of multilayer polymeric articles is reduced by using thinner layers or lower density materials, then energy cost and production cost are lowered, but impact strength and tensile strength deteriorate

Engineering Contradiction:
Improveweight of polymeric articleVSAvoidimpact strength and tensile strength
Core Design Contradiction:
Weight of moving objectVSStrength

Solution Approach 1:

The patent applies composite materials by creating multilayer polymeric articles where each layer has distinct properties. Specifically, it combines layers with different rubber content (e.g., high rubber content layers for impact resistance, low rubber content layers for structural integrity) and different densities (solid layers and foamed layers). This composite structure allows the article to achieve reduced overall weight while maintaining or enhancing impact and tensile strength through the synergistic combination of layers with complementary properties.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent implements local quality by varying the properties of different regions within the polymeric article. Each layer is engineered with specific local characteristics such as rubber content concentration, density, and thickness tailored to its functional requirement. For example, outer layers may have higher rubber content for impact protection while inner layers have lower rubber content for dimensional stability, allowing the article to optimize strength-to-weight ratio through spatially differentiated material properties.

Inventive Principle:
Principle #3Local quality

2Strength

If solid polymer layers are used to maintain structural integrity, then impact strength and tensile strength are maintained, but weight and energy consumption increase

Engineering Contradiction:
Improveimpact strength and tensile strengthVSAvoidweight of polymeric article
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The patent utilizes porous materials by incorporating foamed polymer layers with controlled cell structures into the multilayer article. These foamed layers provide thermal insulation and reduce overall weight while maintaining adequate mechanical strength through their cellular architecture. The porous structure allows the material to achieve lower density without completely sacrificing structural integrity, as the foam cells can be engineered to provide both weight reduction and mechanical support.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent combines solid polymer layers with foamed polymer layers to create a composite structure where each component performs its optimal function. The solid layers provide structural integrity and strength, while the foamed layers contribute weight reduction and thermal insulation. This composite approach allows the article to achieve an optimized balance between weight, strength, and insulation properties that neither material type could achieve alone.

Inventive Principle:
Principle #40Composite materials

3Weight of moving object

If foamed polymeric layers are used to reduce weight, then density and weight are reduced, but manufacturing complexity increases

Engineering Contradiction:
Improveweight of polymeric articleVSAvoidmanufacturing process complexity
Core Design Contradiction:
Weight of moving objectVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the polymeric article into multiple discrete layers with different properties (solid layers, foamed layers, high rubber content layers, low rubber content layers). Each layer can be manufactured separately using optimized processes and then bonded together, which simplifies the overall manufacturing complexity compared to creating a single homogeneous structure with equivalent properties. This segmentation allows independent optimization of each layer's fabrication process.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent merges multiple manufacturing processes into an integrated multilayer fabrication system. By combining extrusion, foaming, and lamination processes into a coordinated manufacturing sequence, the patent achieves weight reduction through foamed layers while managing complexity through process integration. The merging of these processes allows simultaneous production of multiple layer types in a single manufacturing line, reducing the actual complexity increase despite the multifaceted nature of the structure.

Inventive Principle:
Principle #5Merging (Combining)

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

This approach results in a reduced weight multilayer polymeric article with preserved impact and tensile strength, offering energy savings in thermoforming and improved opacity, suitable for applications like refrigeration insulation liners.

Implementation Method 1

incorporating a foaming agent to reduce density

Methodology Applied
Scientific EffectFoaming: Foam

Data Source

PatentEP2268473B1Methods of making reduced weight multilayer polymeric articles
Publication Date: 2019.07.24 FINA TECH INC
  • EP2268473B1 patent drawingFigure 1
  • EP2268473B1 patent drawingFigure 2
  • EP2268473B1 patent drawingFigure 3

AI summary

A method of preparing a refrigeration insulation liner comprising forming a multilayer polymeric sheet comprising at least one foam layer and at least one solid layer disposed adjacent to the foam layer, shaping the multilayer polymeric sheet into the liner, wherein the liner is an insulator, wherein the layers of the sheet adhered to each other by melt extrusion, and wherein the liner resists degradation in the event of contact with a refrigerant. A method of preparing a refrigeration device liner comprising coextruding a foamed polystyrene layer between two solid layers of high impact polystyrene to form a sheet, thermoforming the sheet into the liner, and incorporating the liner into the refrigeration device. A method of forming a multilayer polymeric sheet comprising melting a first styrenic polymer composition, melting and foaming a second styrenic polymer composition, and coextruding the first and second styrenic polymer compositions to form a multilayer polymeric sheet.