Stretch Film Tray Wrapping with Integrated Alignment Fingers

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Solution Overview

Problem

Existing packaging machines face issues with packaging tray misalignment, leading to malfunctions and unsatisfactory film folding during the wrapping process, necessitating complex alignment mechanisms.

Innovation Solution

A packaging machine with alignment fingers integrated into the lifting table's support surface, ensuring trays are aligned parallel to the conveyor direction by pressing against these fingers during transport, followed by a controlled transition to the lifting position, using a lifting device to secure the film around the tray.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a complex alignment mechanism is used to ensure tray alignment, then packaging quality is improved, but device complexity increases

Engineering Contradiction:
Improvetray alignmentVSAvoidalignment mechanism
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent extracts the alignment function from a complex external alignment mechanism and integrates it into the lifting table itself through alignment fingers. This removes the need for separate complex alignment devices while maintaining alignment precision during the lifting operation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The lifting table is given multiple functions: it not only lifts the packaging tray but also provides alignment through its integrated alignment fingers. This multi-functionality eliminates the need for dedicated alignment mechanisms, reducing overall device complexity while maintaining alignment quality.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Manufacturing precision

If trays are aligned by pressing against alignment fingers during transport, then alignment precision is improved, but the risk of tray damage increases

Engineering Contradiction:
Improvetray alignmentVSAvoidtray damage
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The alignment fingers are positioned to engage with the tray during the dynamic transport phase, allowing alignment to occur naturally through the motion of the conveyor rather than through static forcing. The tray is guided into alignment as it moves onto the lifting table, reducing impact forces.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The alignment fingers act as an intermediary element between the conveyor and the lifting table, providing a gentle guiding surface that directs the tray into proper alignment without requiring forceful contact or complex mechanical intervention that could cause damage.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If the lifting table is held in central position during transport, then alignment is improved, but the packaging speed decreases

Engineering Contradiction:
Improvetray alignmentVSAvoidpackaging speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The alignment is performed preliminarily during the transport phase while the tray is moving onto the lifting table. By the time the lifting operation begins, the tray is already aligned, eliminating the need for additional alignment time during the packaging cycle and maintaining high productivity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The alignment process occurs continuously during the normal transport and lifting operation without interrupting the packaging flow. The lifting table remains in the central position throughout the cycle, providing continuous alignment guidance while the tray is being positioned and lifted, maintaining uninterrupted packaging speed.

Inventive Principle:
Principle #20Continuity of useful action

Data Source

PatentEP4201824B1Packaging machine and method for packaging with stretch film
Publication Date: 2026.01.28 BIZERBA GMBH & CO KG
  • EP4201824B1 patent drawingFigure 1
  • EP4201824B1 patent drawingFigure 2
  • EP4201824B1 patent drawingFigure 3a

AI summary

The present invention relates to a method for operating a packaging machine for wrapping food packaging trays with a packaging film, in particular a plastic film, in which the packaging film is fed to a holding mechanism with two spaced-apart holding elements to hold the fed packaging film on two opposite sides, and subsequently a fed packaging tray is pressed against the fed packaging film by lifting it from below, and then the opposite sides of the packaging film are guided under the packaging tray. The lifting of the packaging tray is effected by a lifting device that raises a lifting table designed to receive the packaging tray from a transfer position to a packaging position, and wherein the packaging tray is transported from a loading position to the transfer position via a feed belt.The lifting table is held in a central position by the lifting device, while the feed conveyor transports the packaging tray on an intermediate section between the loading position and the transfer position. Furthermore, the invention relates to a packaging machine for carrying out a method according to the invention for operating a packaging machine.