Mandrel Sealing of Paper End Closures for Hermetic Containers

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Solution Overview

Problem

Existing container sealing technologies using metal closures hinder recyclability, leading to waste and environmental impact, and existing equipment is incompatible with paper-based closures due to their unique properties.

Innovation Solution

A sealing system utilizing an integrated mandrel and ejector mechanism to apply paper-based end closures at high speeds, ensuring hermetic seals without defects, and enabling recyclability by using a paper-based composite bottom.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If metal closures are used for sealing containers, then hermetic sealing is achieved, but recyclability is compromised

Engineering Contradiction:
Improvehermetic sealingVSAvoidrecyclability
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent changes the material parameter from metal to paper-based composite, transforming the closure from non-recyclable to recyclable while maintaining sealing functionality through controlled deformation and fusion of the paper layers during the sealing process

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses composite paper materials with specific layers (including heat-sealable layers) that combine the recyclability of paper with the sealing capabilities traditionally provided by metal, creating a multi-layer composite structure that achieves both hermetic sealing and recyclability

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If paper-based closures are used to improve recyclability, then environmental sustainability is enhanced, but compatibility with existing seaming equipment is lost

Engineering Contradiction:
ImproverecyclabilityVSAvoidequipment compatibility
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent employs dynamic control of the sealing process, using controlled deformation and real-time adjustment of sealing parameters to accommodate the flexibility and unique properties of paper-based closures, enabling existing equipment to handle paper closures effectively

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention modifies process parameters (temperature, pressure, deformation control) to suit paper-based closures, transforming the sealing mechanism from metal-appropriate parameters to paper-appropriate parameters while using the same equipment hardware

Inventive Principle:
Principle #35Parameter changes

3Productivity

If high-speed sealing is implemented to increase productivity, then manufacturing efficiency is improved, but sealing quality and defect prevention become more challenging

Engineering Contradiction:
Improvesealing speedVSAvoidsealing quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary deformation to the paper closure before final sealing, pre-positioning and pre-shaping the material to ensure proper alignment and reduce variability during high-speed operation, thereby maintaining sealing quality at increased speeds

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention incorporates feedback control mechanisms that monitor sealing quality in real-time and adjust process parameters dynamically, ensuring consistent sealing performance even at high production speeds where variability would normally increase

Inventive Principle:
Principle #23Feedback

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 system produces hermetically sealed containers with high recyclability, maintaining product freshness and integrity under varying atmospheric conditions, while avoiding defects like pin holes, pleats, or cracking, and ensuring stable shelf behavior.

Implementation Method 1

The system comprises a sealing head configured to receive the paper-based disc and hermetically seal the paper-based disc to the container body

Methodology Applied
Scientific EffectHeat fusion: Heating

Implementation Method 2

The mandrel assembly may comprise an outer mandrel and an inner mandrel. The inner mandrel may be configured to extend into the container body and urge the paper-based disc into the container body to form a composite bottom

Methodology Applied
Scientific EffectMechanical deformation: Deformation

Implementation Method 3

The ejectors may be configured to extend into the container body and retract from the container bottom during outfeed

Methodology Applied
Scientific EffectMechanical force: Force

Data Source

PatentEP4182153B1Systems and methods for the application and sealing of end closures on containers
Publication Date: 2026.01.21 SONOCO DEVELOPMENT INC
  • EP4182153B1 patent drawingFigure 1
  • EP4182153B1 patent drawingFigure 2
  • EP4182153B1 patent drawingFigure 3

AI summary

The invention is directed to a system and method for hermetically sealing a closure to a container comprising a die assembly and a mandrel assembly. The mandrel assembly comprises an outer mandrel, an inner mandrel, and an ejector disposed within an inner circumference of the inner mandrel. At least the outer mandrel is configured to translate a first distance in a first time period, the inner mandrel and the ejector are configured to translate a second distance in a second time period, the inner mandrel is configured to retract a third distance in a third time period, and the ejector is configured to retract the third distance in a fourth time period.