Multi-layered IBC Liners with EVOH and TPE

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Solution Overview

Problem

Existing bulk container liners face challenges in providing both oxygen barrier protection and abuse resistance while being economical and recyclable, as they often rely on metal-containing films that complicate recycling and mono-layered polymer films that lack sufficient protection.

Innovation Solution

The use of multi-layered plies comprising an ethylene-vinyl alcohol (EVOH) copolymer film with a thermoplastic elastomer (TPE) centered between linear low density polyethylene (LLDPE) or very low density polyethylene (VLDPE) layers, which provides both oxygen barrier protection and flex crack resistance, and can be tailored for specific liquid products.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If metal-containing polymer films are used for oxygen barrier purposes, then oxygen barrier protection is improved, but recycling complexity and cost increase

Engineering Contradiction:
Improveoxygen barrier protectionVSAvoidrecycling complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts and removes the metal-containing barrier layer from the liner structure, replacing it with a metal-free alternative. This eliminates the recycling complexity associated with metal separation while maintaining the oxygen barrier function through multi-layered polymer construction with EVOH and TPE layers.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention employs composite materials by creating a multi-layered structure combining different polymer layers (LLDPE, VLDPE, EVOH, TPE) to achieve the oxygen barrier protection previously provided by metal films. This composite approach allows for both barrier performance and recyclability.

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If mono-layered polymer films are used for abuse resistance, then manufacturing simplicity is improved, but protection against cracking and pinholes deteriorates

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidabuse resistance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The invention segments the liner into multiple plies and layers, with each layer providing specific functionality. The LLDPE and VLDPE layers provide abuse resistance and flex crack protection, while the EVOH and TPE layers provide oxygen barrier properties. This segmentation allows each layer to be optimized for its specific function while maintaining overall manufacturing efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention uses composite materials by combining multiple polymer layers with different properties. The outer LLDPE/VLDPE layers provide mechanical strength and abuse resistance, while the inner EVOH/TPE layers provide oxygen barrier protection, creating a liner that excels in both durability and barrier performance.

Inventive Principle:
Principle #40Composite materials

3Reliability

If multi-layered plies with EVOH and TPE are used, then both oxygen barrier protection and flex crack resistance are improved, but structural complexity increases

Engineering Contradiction:
Improveoxygen barrier protection and flex crack resistanceVSAvoidstructural complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention merges multiple functions into a single integrated liner structure. The multi-layered plies combine oxygen barrier protection, flex crack resistance, and abuse resistance in one unified construction, eliminating the need for separate components and simplifying the overall system while maintaining high performance.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention applies local quality by assigning specific properties to specific layers. The outer LLDPE/VLDPE layers are designed for mechanical strength and abuse resistance, while the inner EVOH/TPE layers are designed for oxygen barrier properties. This localized optimization allows each layer to perform its specific function efficiently.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3083426B1Liners for bulk containers
Publication Date: 2018.11.07 BEMIS COMPANY INC
  • EP3083426B1 patent drawingFigure 1~2
  • EP3083426B1 patent drawingFigure 3~4

AI summary

Described are liners for bulk containers such as intermediate bulk containers (IBC) that are abuse-resistant and barrier-providing. The liners have at least one sidewa!l that is multi-plied and the plies are multi-layered. The liners are preferably metal-free. Each ply independently comprises at least three layers that comprise: a first layer and a third layer each comprising a Iinear low density polyethylene (LLDPE) or a very low density polyethylene (VLDPE); and a second layer between the first and third layers and comprising a thermoplastic oxygen barrier of ethylene-vinyl alcohol copolymer (EVOH) and a thermoplastic elastomer (TPE). A ply may further comprise a fourth layer and a fifth layer, each comprising a polyamide, the fourth layer being located between the first and second layers and the fifth layer being located between the second and third layers. Methods of making and using the liners are also provided.