Polyethylene Barrier Laminates for Recyclable Flexible Packaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Laminates used in flexible packaging, such as those containing polypropylene, polyamide, and polyethylene terephthalate, are difficult to recycle due to incompatible materials, hindering sustainable recycling efforts despite offering good performance properties like heat-resistance and barrier performance.
Innovation Solution
A laminate structure comprising a multilayer film with a barrier layer of ethylene vinyl alcohol copolymer, a sealant layer with at least 70 wt.% of an ionomer of ethylene acid copolymer or polyethylene elastomer/plastomer, and a tie layer, adhered to a polyethylene film with specific density and melting properties, enabling full recyclability within polyethylene streams while maintaining performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional multi-layer laminates containing polypropylene, polyamide, and polyethylene terephthalate are used, then good performance properties (heat-resistance, barrier performance, printability) are achieved, but recyclability is severely limited due to incompatible materials
Solution Approach 1:
The invention uses polyethylene as the base polymer for all layers including the barrier layer (EVOH), sealant layer, and adhesive layer, creating a homogeneous polyethylene-based laminate structure that is fully recyclable while maintaining diverse functional properties through polymer modifications and copolymer compositions
Solution Approach 2:
The invention creates a composite laminate structure where EVOH barrier layer, polyethylene sealant layer, and polyethylene adhesive layer are combined, achieving both high barrier performance and full recyclability within the polyethylene recycling stream
2Productivity
If faster packaging speeds are implemented, then productivity increases, but maintaining seal quality and barrier performance becomes more difficult
Solution Approach 1:
The invention modifies the sealant layer composition to contain at least 70 wt% of specific polyethylene elastomers or ionomers with controlled melting temperatures (100°C or less), enabling reliable sealing at higher packaging speeds by adjusting the thermal parameters of the sealant material
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 laminate achieves comparable or improved properties like barrier seal performance, oxygen and water vapor transmission rates, heat seal strength, and shrinkage resistance, facilitating faster packaging speeds and full recyclability.
Implementation Method 1
an adhesive adhering the multilayer film to the polyethylene film
Implementation Method 2
a sealant layer, wherein the sealant layer comprises at least 70 wt. % of an ionomer of ethylene acid copolymer or polyethylene elastomer/plastomer having a highest peak melting temperature (Tm) of 100° C. or less
Data Source
AI summary
Provided are barrier laminates including polyethylene which offer heat resistance and a wide sealing window. The laminates can be fully compatible with polyethylene recycling streams and can exhibit improved, maintained, or desirable properties in comparison to existing laminate structures that are not fully compatible with polyethylene recycling streams. The laminate comprises a multilayer film, a polyethylene film, and an adhesive. The adhesive adheres the multilayer film to the polyethylene film to provide the laminate.