Impulse Sealing Bars for Mono-material Foil Packaging

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Solution Overview

Problem

Conventional deep-drawing packaging machines face challenges in producing high-quality seal seams, especially with mono-material foils like PE or HDPE, as the seal seams remain warm and non-resilient, affecting the barrier properties and integrity of the packaging.

Innovation Solution

The deep-drawing packaging machine employs a seal device with a first and second seal tool, each equipped with a pair of pulse seal rails that can be quickly heated and cooled, allowing for efficient energy use and the production of thin, sensitive sealing seams.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional permanently heated sealing tools are used, then sealing function is maintained, but seal seams remain warm and mechanically unloadable, negatively impacting seal quality and barrier properties

Engineering Contradiction:
Improveseal qualityVSAvoidseal seam temperature
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The sealing device uses impulse sealing bars that are heated only during the sealing cycle through controlled current pulses, then rapidly cooled during non-sealing periods. This periodic heating and cooling ensures seal seams are mechanically resilient and dimensionally stable while maintaining reliable sealing function.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The invention changes the thermal state parameter of the sealing tool from continuously hot to dynamically controllable temperature. By adjusting the duration and intensity of current pulses to the impulse sealing bars, the system achieves optimal seal temperature only when needed, then rapidly cools to produce dimensionally stable seal seams.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If impulse sealing bars with rapid cooling capacity are used, then thin and sensitive sealing seams are produced, but device complexity increases

Engineering Contradiction:
Improvesealing seam precisionVSAvoidsealing device complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The invention combines the heating element (resistance-heatable heating conductor) and cooling mechanism (liquid cooling system) into an integrated impulse sealing bar assembly. This merging allows rapid temperature changes within a compact structure, achieving precise sealing seam formation without proportionally increasing device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention replaces traditional mechanical heating systems with electric resistance heating in the impulse sealing bars. This substitution enables precise temporal and spatial control of heat application, allowing rapid heating during sealing and rapid cooling afterward, thereby achieving high sealing precision with controlled complexity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Use of energy by moving object

If impulse sealing bars are used, then energy efficiency is improved through intermittent heating, but device complexity increases due to pulse generation requirements

Engineering Contradiction:
Improvesealing energy consumptionVSAvoidpulse control system complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The impulse sealing bars utilize their own electrical resistance as the heating mechanism, eliminating the need for external heating elements or complex thermal management systems. The resistance of the heating conductor itself serves as the control variable for current supply, creating a self-regulating system that improves energy efficiency without proportionally increasing complexity.

Inventive Principle:
Principle #25Self-service

4Manufacturing precision

If paired sealing tools with multiple impulse sealing bars are used, then seal seam distribution and force application are improved, but device complexity increases

Engineering Contradiction:
Improveseal seam distributionVSAvoidsealing tool configuration complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The sealing device is divided into paired sealing tools, each with multiple impulse sealing bars arranged in specific orientations. This segmentation allows independent control and optimization of each sealing bar, enabling precise distribution of seal seams and balanced force application across the packaging material without requiring an overly complex integrated system.

Inventive Principle:
Principle #1Segmentation

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

This solution enhances the seal process by ensuring that seal seams are mechanically resilient and of high quality, maintaining the barrier properties of the packaging and allowing for the packaging of sensitive products.

Implementation Method 1

The impulse sealing bar is pressed firmly onto the films to be sealed, while the heating band is subjected to a current pulse via a pulse generator, thereby heating it to seal the films together.

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

the electrical resistance of the heating conductor, which varies depending on the current heating conductor temperature, is measured and used as a control variable for the current supply

Methodology Applied
Scientific EffectElectrical resistance: Electrical Resistance

Data Source

PatentEP4070936B1Deep-draw packaging machine with impulse sealing rails and impulse sealing method
Publication Date: 2025.04.02 MULTIVAC SEPP HAGGENMULLER GMBH & CO KG
  • EP4070936B1 patent drawingFigure 1
  • EP4070936B1 patent drawingFigure 2

AI summary

The invention relates to a thermoforming packaging machine (1) comprising, in the production direction (R), a forming station (2) for producing cavities (M) in a film web (8), an insertion section (12) for filling the cavities (M) with a product, a sealing device (3) for sealing the cavities (M) with a top film (10), and a cutting device (4, 5) for separating finished packages, wherein the sealing device (3) has a first sealing tool (13) for a first sealing cycle (S1) and a second sealing tool (14) for a second sealing cycle (S2), wherein the first sealing tool (13) has at least one first pair (15a, 15b) impulse sealing bars aligned in a first orientation relative to the production direction (R) for producing first sealing seam sections (A), and the second sealing tool (14) has at least one second pair of impulse sealing bars (16a, 16b) aligned in a second orientation relative to the production direction (R).16b) for producing second sealing seam sections (B).