Paper Threaded Lid Structure for Stackable Container Sealing

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Solution Overview

Problem

Existing container lids are not environmentally friendly and do not facilitate efficient stacking and secure sealing, particularly for recyclable and compostable materials.

Innovation Solution

A paper lid with a fitting flange that includes a thread protruding over the inner side and a groove, allowing for nesting and secure sealing, made from recyclable and compostable materials, with optional laminations for enhanced durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional plastic lid is used, then sealing performance and durability are improved, but environmental friendliness and recyclability deteriorate

Engineering Contradiction:
Improvesealing performanceVSAvoidenvironmental friendliness
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the material parameter from conventional plastic to paper material, transforming the lid into a recyclable and compostable product while maintaining functional performance through specific structural design elements like the fitting flange and thread configuration

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite construction by combining paper material with a fitting flange structure and thread elements, creating a multi-functional lid that achieves both environmental sustainability and reliable sealing through the integration of different structural components

Inventive Principle:
Principle #40Composite materials

2Productivity

If the fitting flange diameter is reduced for nesting, then stackability is improved, but structural strength deteriorates

Engineering Contradiction:
ImprovestackabilityVSAvoidstructural strength
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The patent implements nesting capability by designing the fitting flange with a reduced diameter at its end, allowing one lid to be placed inside another for compact stacking and storage, optimizing space utilization without compromising the overall structural integrity through proper material distribution

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent applies local quality by varying the diameter of the fitting flange along its length, with the end portion having a reduced diameter for nesting while the main body maintains sufficient diameter and thickness to provide the necessary structural strength and connection area

Inventive Principle:
Principle #3Local quality

3Reliability

If the thread protrusion height is increased for secure engagement, then sealing reliability is improved, but manufacturing precision requirements worsen

Engineering Contradiction:
Improveengagement reliabilityVSAvoidthread precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies partial action by providing a thread protrusion that extends only partially beyond the inner side of the fitting flange (0.5-2.0 mm), which is sufficient to engage with the container thread for reliable sealing while avoiding the need for excessive protrusion that would demand higher manufacturing precision

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP4490062B1Threaded paper lid for container
Publication Date: 2026.01.28 SEDA INT PACKAGING GRP SPA
  • EP4490062B1 patent drawingFigure 1~2
  • EP4490062B1 patent drawingFigure 3~4

AI summary

The present invention relates to a paper lid (3). The paper lid (3) comprises a central lid panel (7, 31) and a fitting flange (5). The fitting flange (5) is adapted to be arranged on a receptacle (2) of a container (1). The fitting flange (5) is made of paper material, wherein the fitting flange (5) forms a radially outer side (9) of the paper lid (3). A groove (11) is formed in the radially outer side (9) of the fitting flange (5) and the groove (11) forms a thread (13) on a radially inner side (15) of the fitting flange (5). The thread (13) is made of paper material. The invention further provides a container, stack of at least two containers and a method for producing a lid.