Container Lid Liner Thickness Variation for Embossing Integrity

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Solution Overview

Problem

Existing easily openable container lids for gas-containing liquids face manufacturing cost increases due to complex processes and potential damage during embossing, and are unsuitable for containers under positive pressure.

Innovation Solution

A container lid with a synthetic resin liner adhered over its entire surface, featuring thin-walled central and thick-walled peripheral sections, and a downwardly protruding outer ridge, which reduces manufacturing costs and prevents damage during embossing, while maintaining effective sealing under positive pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the liner is in a state of non-adhesion or weak adhesion to the inner surface of the top panel wall in a specific region, then the liner can be easily separated from the embossing tool, but the manufacturing process becomes complicated and requires local non-adhesive films, increasing manufacturing cost

Engineering Contradiction:
Improveliner separation from embossing toolVSAvoidmanufacturing process complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent applies local quality by creating a non-adhesive region specifically at the peripheral edge section of the liner where it contacts the embossing tool, while maintaining adhesive properties in the central section. This is achieved by forming a non-adhesive layer or structure only in the necessary peripheral region, allowing easy separation during embossing without requiring complex manufacturing processes or additional films throughout the entire liner.

Inventive Principle:
Principle #3Local quality

2Strength

If the peripheral edge section of the liner is made thick-walled to prevent deformation during embossing, then the liner rigidity increases, but the amount of synthetic resin material increases, increasing manufacturing cost

Engineering Contradiction:
Improveliner rigidityVSAvoidsynthetic resin material amount
Core Design Contradiction:
StrengthVSQuantity of substance

Solution Approach 1:

The patent implements local quality by varying the wall thickness of the liner across different regions. The peripheral edge section is made thick-walled to provide the necessary rigidity and prevent deformation during embossing, while the central section is made thin-walled to reduce material consumption. This localized thickness variation optimizes both structural strength and material efficiency.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The liner is segmented into distinct thickness zones: a thick-walled peripheral edge section and a thin-walled central section. This segmentation allows each region to be optimized for its specific function - the peripheral section for structural support during manufacturing and the central section for material economy.

Inventive Principle:
Principle #1Segmentation

3Quantity of substance

If the liner is made thin-walled to reduce material usage, then manufacturing cost decreases, but the liner becomes vulnerable to damage during embossing and under positive pressure

Engineering Contradiction:
Improvesynthetic resin material amountVSAvoidliner integrity under pressure
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent resolves this contradiction by applying local quality through spatial variation in wall thickness. The thin-walled central section reduces material usage and cost, while the thick-walled peripheral edge section maintains structural integrity during embossing and under positive pressure conditions. The strategic placement of thicker material only where mechanically necessary preserves reliability while minimizing overall material consumption.

Inventive Principle:
Principle #3Local quality

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 allows for reduced manufacturing costs and prevents damage to the seal even under impact, ensuring effective sealing for containers under positive pressure without increasing material usage.

Implementation Method 1

a liner having a thin-walled central section and a thick-walled peripheral edge section, and having a downwardly protruding outer ridge formed in a radially outward region of the thick-walled peripheral edge section, wherein the liner is adhered over the entire surface thereof to the inner surface of the top panel wall

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP3037361B1Easily openable container lid
Publication Date: 2022.11.09 NIPPON CLOSURES
  • EP3037361B1 patent drawingFigure 1
  • EP3037361B1 patent drawingFigure 2
  • EP3037361B1 patent drawingFigure 3

AI summary

An easily openable container lid (2), which has a shell (4) and a liner (6) embossed on the inner surface of a top panel wall (8) of the shell and has a pair of scores (18a and 18b) formed in the shell, is improved as follows: When the liner is embossed, the liner is neither deformed nor damaged. Even if an impact is applied to the container lid, damage to the sealing of a mouth-neck section of a container is avoided, where possible. Nonetheless, the manufacturing cost can be sufficiently reduced. The liner is adhered over the entire surface thereof to the inner surface of the top panel wall. At least second portions (18a-2 and 18b-2) of the pair of scores are formed by forming grooves on the inner surface side of the shell, and are extended along the peripheral edge of the liner radially outwardly of the liner. Moreover, the liner has a thin-walled central section (22) and a thick-walled peripheral edge section (24), and is configured to have a downwardly protruding outer sealing ridge (26) formed in a radially outward region of the thick-walled peripheral edge section. The thickness (T1) of the thin-walled central section and the thickness (T2) of the thick-walled peripheral edge section are set within required ranges.