Multilayer Sealant Structure for Easy-Open Packaging

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Solution Overview

Problem

Existing easy-open package technologies face challenges in achieving reliable and reproducible sealing due to variability in sealant layer composition, sealing conditions, and aging time, particularly in packages with different compositions such as rigid and flexible containers and lids, necessitating a multilayer structure that allows for easy open sealing across various applications and processing conditions.

Innovation Solution

A multilayer structure comprising a sealant layer formed from ethylene-based polymers and a cohesive delamination layer formed from a polymer blend of elastomeric propylene-based polymers and high pressure low density polyethylene, ethylene acrylic acid copolymers, or their combinations, which ensures consistent sealing performance across a wide range of temperatures and processing conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a sealant layer with consistent composition is used, then sealing reliability is improved, but adaptability to different package compositions (rigid and flexible) deteriorates

Engineering Contradiction:
Improvesealing reliabilityVSAvoidadaptability to different package compositions
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent applies parameter changes by utilizing the elastomeric propylene-based polymer's ability to change its physical state and properties across different temperature ranges. The polymer's glass transition temperature and melting point characteristics allow the sealant layer to adapt its sealing behavior to match different package compositions (rigid or flexible) while maintaining consistent composition, thereby resolving the contradiction between sealing reliability and adaptability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite materials by creating a sealant layer that is a blend of elastomeric propylene-based polymer with other polymers (such as polyethylene, polypropylene, or their copolymers). This composite structure enables the sealant to exhibit both reliable sealing properties and adaptability to different package types, as the different polymer components contribute different functional characteristics that work together to achieve universal sealing performance

Inventive Principle:
Principle #40Composite materials

2Ease of operation

If sealant layer composition is optimized for easy opening, then ease of operation is improved, but sealing strength deteriorates

Engineering Contradiction:
Improveease of openingVSAvoidsealing strength
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The patent applies dynamics by utilizing the elastomeric propylene-based polymer's temperature-dependent behavior. At sealing temperatures, the polymer provides strong adhesion for secure sealing, while at lower temperatures (after cooling), it maintains sufficient bond strength for normal use but allows easy opening when force is applied. The dynamic response of the polymer to temperature and stress changes enables both strong sealing and easy opening without compromising either property

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent uses parameter changes by exploiting the elastomeric polymer's glass transition temperature characteristics. Below the glass transition temperature, the polymer is rigid and provides strong sealing; above it, the polymer becomes more flexible and allows easy opening. This parameter change with temperature enables the seal to provide both strong sealing strength and ease of opening

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If a broad seal window is achieved, then adaptability to processing conditions is improved, but manufacturing precision deteriorates

Engineering Contradiction:
Improveadaptability to processing conditionsVSAvoidsealing temperature control
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by utilizing the elastomeric propylene-based polymer's broad temperature range for effective sealing. The polymer maintains its sealing properties from approximately 80°C to 150°C, providing a broad seal window that accommodates variations in processing conditions without requiring precise temperature control, thereby achieving adaptability while reducing manufacturing precision requirements

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite materials by blending the elastomeric propylene-based polymer with other polymers that have complementary thermal properties. This composite structure creates a sealant layer with a broad effective sealing temperature range, allowing the material to adapt to different processing conditions while maintaining consistent sealing performance without requiring tight temperature control

Inventive Principle:
Principle #40Composite 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 structure provides a broad seal window, allowing for easy opening and consistent seal strength across varying temperatures, from 120°C to 180°C, and is suitable for a variety of applications, including food and beverage containers, by utilizing a cohesive failure layer that facilitates separation without significant increase in seal force with temperature.

Implementation Method 1

a sealant layer formed from one or more ethylene-based polymers

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

a cohesive delamination layer adjacent to the sealant layer

Methodology Applied
Scientific EffectCohesion: Cohesion

Implementation Method 3

a cohesive delamination layer adjacent to the sealant layer and formed from a polymer blend which comprises an elastomeric propylene based polymer

Methodology Applied
Scientific EffectDelamination:

Data Source

PatentEP3209496B1A multilayer structure, a film made therefrom and a package formed therefrom
Publication Date: 2020.12.30 DOW GLOBAL TECHNOLOGIES LLC
  • EP3209496B1 patent drawingFigure 1A~1C
  • EP3209496B1 patent drawingFigure 2
  • EP3209496B1 patent drawingFigure 3A~3C

AI summary

A multilayer structure including a first layer; a sealant layer formed from one or more ethylene-based polymers; and a cohesive failure layer adjacent to the sealant layer and formed from a polymer blend which comprises an elastomeric propylene based polymer and a second polymer, wherein the second polymer is selected from the group consisting of high pressure low density polyethylene, high density polyethylene, ethylene acrylic acid copolymers, ethylene (meth) acrylic acid copolymers and combinations thereof is provided.