Packaging Sleeve Weakening Lines for Clean Container Separation

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Solution Overview

Problem

Existing packaging containers face issues with unreliable and difficult sleeve removal due to tearing during separation, especially in automated processes, and require improved cutting methods to ensure clean and efficient detachment.

Innovation Solution

A packaging container design featuring a first weakening line parallel to the end section and a second weakening line, preferably forming a circular arc or two straight lines at angles, allows for reliable separation by applying radial tensile or compressive forces, with optional recesses to facilitate cutting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single weakening line is used for sleeve separation, then the structure is simple, but reliable cutting cannot be achieved in all applications and tearing occurs during separation

Engineering Contradiction:
Improvecuff structureVSAvoidseparation reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The single weakening line is divided into two separate weakening lines (first and second weakening lines) positioned at different locations on the cuff. This segmentation allows the cutting force to be distributed across multiple locations, preventing concentration of stress at a single point and eliminating the tearing problem while maintaining overall structural simplicity

Inventive Principle:
Principle #1Segmentation

2Ease of operation

If a weakening line is positioned to enable easy cutting, then separation is simple, but the required radial outward pulling force is problematic for automated separation processes

Engineering Contradiction:
Improveseparation easeVSAvoidautomated separation compatibility
Core Design Contradiction:
Ease of operationVSExtent of automation

Solution Approach 1:

The solution transitions from requiring radial outward pulling force to applying axial compressive or tensile forces along the longitudinal axis of the container. This dimensional change in force application makes the separation process compatible with automated handling systems while maintaining ease of operation

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Ease of manufacture

If the cuff is made from overlapping end sections, then the cuff can be formed from a planar blank, but separation may cause tearing at the overlap area

Engineering Contradiction:
Improvecuff manufacturingVSAvoidseparation cleanliness
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The first weakening line is positioned specifically adjacent to the overlap area while the second weakening line is positioned at a distance from it. This local differentiation ensures that the overlap area is properly addressed during separation without compromising the overall structural integrity, enabling clean separation without tearing at the overlap region

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4438508B1Packaging container
Publication Date: 2026.04.22 W U H FERNHOLZ
  • EP4438508B1 patent drawingFigure 1~2
  • EP4438508B1 patent drawingFigure 3~4

AI summary

The invention relates to a packaging container encased in a sleeve (2) formed from a planar blank (20) whose end sections (3, 4) are joined together in an overlap area (21), wherein at least one first weakening line (6) is arranged in the blank (20), which runs parallel to an end section (3, 4) and via which the sleeve can be separated without tools. A second weakening line (7) is arranged spaced apart from the first weakening line (6), which is essentially in the form of a circular arc or two straight lines set at an angle to each other.