Tearable Package Seal Using Polybutene Blend and Corona Treatment

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Solution Overview

Problem

Existing tear-open packaging technologies face challenges in achieving a reliable, easy-to-open seal that is not too strong, ensuring uniform tearing, and minimizing noise and fragment formation, especially when used with diverse material combinations like polyethylene, polystyrene, and aluminum or paper, often resulting in either insufficient or excessively strong connections.

Innovation Solution

A polymeric blend in the sealing layer comprising 2 to 25% polybutene, 60 to 98% polyethylene, and less than 20% remainder, with surface modification by corona treatment to achieve a peelable and separable heat-sealed seam, ensuring strong yet easy separation across various substrate materials, including aluminum and paper.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the sealing layer and substrate layer are heat-sealed to achieve a reliable connection, then the bond strength increases, but the separability decreases

Engineering Contradiction:
Improvebond strengthVSAvoidseparability
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The patent modifies the surface properties of the sealing layer through physical surface treatment processes (corona treatment, plasma treatment, or flame treatment) to change the surface energy and chemical composition. This creates an optimal balance where the bulk material provides strong bonding while the treated surface allows for controlled separation, resolving the contradiction between bond strength and separability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite material structures where the sealing layer combines base polymer materials with surface-treated layers. The multi-layer composite structure enables different functions in different layers: strong adhesion to the substrate while maintaining peelability at the sealed seam, thus resolving the contradiction between strong bonding and easy separation

Inventive Principle:
Principle #40Composite materials

2Reliability

If the sealing strength is increased to ensure secure closure, then the reliability improves, but the ease of opening by hand deteriorates

Engineering Contradiction:
Improvesecure closureVSAvoidease of opening
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

Physical surface treatment processes modify the surface parameters of the sealing layer without significantly altering the bulk material properties. This allows the sealed seam to maintain strong closure reliability while the treated surface enables manual peelability, resolving the contradiction between secure closure and easy opening

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If a simple material combination is used to reduce cost, then the manufacturing cost decreases, but the sealing performance and separability control worsen

Engineering Contradiction:
Improvecost-effectivenessVSAvoidsealing performance
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies physical surface treatment processes during or before the sealing operation to prepare the sealing layer surface. This preliminary surface modification ensures optimal sealing performance and separability control without requiring complex material formulations or additional sealing process steps, maintaining cost-effectiveness while achieving precise sealing performance

Inventive Principle:
Principle #10Preliminary action

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 solution enables a seamless, noise-reduced, and visually distinct tearing process with a uniform fracture pattern, ensuring secure closure and easy opening without requiring tools, even for users with limited dexterity, while maintaining cost-effectiveness and universal applicability.

Implementation Method 1

In the corona process an electrode is used to bring a shower of sparks onto the surface to be treated

Methodology Applied
Scientific EffectCorona discharge: Corona Discharge

Implementation Method 2

A plasma process can be carried out both in the low-pressure range and at atmospheric pressure using suitable systems

Methodology Applied
Scientific EffectPlasma: Plasma

Implementation Method 3

a flame treatment, in particular with a gas flame

Methodology Applied
Scientific EffectFlame treatment: Combustion

Data Source

PatentEP3339018B1Tearable package
Publication Date: 2020.05.06 MONDI AG
  • EP3339018B1 patent drawingFigure 1
  • EP3339018B1 patent drawingFigure 2

AI summary

The invention relates to a tear-open package comprising a first packaging material (1) and a second packaging material (2) joined together at a separable seal (3), wherein a sealing layer (4) of the first packaging material (1) is connected at the separable seal (3) to an immediately adjacent substrate layer of the second packaging material (2), the substrate layer comprising as its main component aluminum, paper, or a polymer selected from the group consisting of polyethylene terephthalate (PET), polystyrene (PS), polyvinyl chloride (PVC), polycarbonate (PC), polylactic acid (PLA), and polyamide (PA), and wherein the sealing layer (4) has a corona-modified surface adjacent to the substrate layer. According to the invention, the polymeric components of the sealing layer (4) form a blend with 2 to 25 wt.% polybutene (PB), 60 to 98 wt.% polyethylene, and less than 20 wt.% residue.