Thermoforming Plastic Cup Packaging With Localized Heating

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Solution Overview

Problem

Existing methods for producing plastic packaging for pasty products require significant modifications to existing machinery and are inefficient in heating both the external and internal faces of the cup, complicating the sealing process and leading to costly investments.

Innovation Solution

A process using two thin plastic sheets where the first sheet is cut and shaped to form a cup with preheated areas for thermoforming, and a second sheet is sealed over the cup to create an easy-opening, leaktight packaging solution, utilizing existing machinery with minimal modifications and heat-sealable lacquer for internal sealing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If plastic sheets are used to replace aluminum for packaging pasty products, then energy consumption is reduced, but the material cannot retain the memory of bends and requires special equipment for shaping

Engineering Contradiction:
Improveenergy consumptionVSAvoidshaping capability
Core Design Contradiction:
Use of energy by moving objectVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by pre-heating the plastic sheet in selected areas before folding. The heating step softens the plastic material in advance, enabling it to be shaped by folding without requiring complex hot bending equipment. This preliminary thermal preparation allows the material to retain bends effectively during the forming process.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the physical parameter of the plastic sheet by heating it to a temperature where the material becomes more pliable and can be folded. This parameter change (temperature increase) transforms the material properties temporarily during shaping, allowing bends to be retained without special equipment.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If hot bending tools are used to shape plastic sheets, then the packaging can be formed, but costly equipment investments are required

Engineering Contradiction:
Improvepackaging formationVSAvoidequipment complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical hot bending system with a combination of localized heating and simple folding mechanics. Instead of using complex heated bending tools, the invention uses heating elements to soften specific areas of the sheet, then employs straightforward folding operations to form the packaging shape.

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

Solution Approach 2:

The patent segments the heating process by applying heat only to selected areas of the plastic sheet that require bending, rather than heating the entire sheet or using a complex overall heating system. This localized approach simplifies the equipment needed while achieving the desired shaping.

Inventive Principle:
Principle #1Segmentation

3Shape

If external face heating is used during cup formation, then shaping is possible, but internal sealing lacquer cannot be heated complicating the sealing process

Engineering Contradiction:
Improvecup formationVSAvoidsealing process
Core Design Contradiction:
ShapeVSEase of manufacture

Solution Approach 1:

The patent applies local quality by providing different thermal treatments to different areas of the cup. The external face receives heating for shaping, while the internal face where the sealing lacquer is applied receives separate heating through the wall of the cup after formation. This localized differential heating allows both shaping and sealing to be performed effectively.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent performs preliminary shaping of the cup using external heating before applying the sealing lacquer. The cup is formed first, then subsequently heated through its walls to activate the sealing lacquer on the internal face. This sequential preliminary action separates the shaping and sealing operations, simplifying the overall process.

Inventive Principle:
Principle #10Preliminary action

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 method allows for efficient production of plastic packaging for pasty products with minimal equipment changes, ensuring effective sealing and easy opening, while reducing energy consumption by using polypropylene, a less energy-intensive material compared to aluminum.

Implementation Method 1

The heating of the sheet can be carried out by contact with at least one heating plate hollowed out in the parts to be spared

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

The heating of the sheet can be carried out by contact with at least one heating plate hollowed out in the parts to be spared or by infrared radiation

Methodology Applied
Scientific EffectInfrared radiation: Infrared Radiation

Implementation Method 3

The heating of the sheet can be carried out by contact with at least one heating plate hollowed out in the parts to be spared or by infrared radiation or by blowing hot air

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 4

the tab is sealed by heat sealing on the second side face

Methodology Applied
Scientific EffectHeat sealing: Heating

Implementation Method 5

the edges of the cover are sealed on the side faces of the bucket by clamping external heating jaws against the piston

Methodology Applied
Scientific EffectHeat sealing: Heating

Implementation Method 6

the rims of the side walls of the cup are folded against the upper face of the lid and are sealed by heat sealing using a heating pad

Methodology Applied
Scientific EffectHeat sealing: Heating

Data Source

PatentEP2238037B1Method for packaging a pasty product in an easily opened, sealed packaging made of plastic material
Publication Date: 2011.09.07 FROMAGERIES BEL LA VACHE QUI RIT
  • EP2238037B1 patent drawingFigure 1
  • EP2238037B1 patent drawingFigure 2
  • EP2238037B1 patent drawingFigure 3

AI summary

The invention relates to a method for packaging a pasty product such as processed cheese or fresh processed cheese in an easily opened, sealed packaging made of two thin sheets of a plastic material, i.e. a first sheet (4) defining a cup (8) having a bottom (80) and side surfaces (81) and a second sheet defining a lid (13) tightly sealed to the edges (81A) of the cup, wherein said method comprises: cutting the first sheet (4) along an adapted outline; conforming the first sheet (4) by folding in order to form a cup (8) having side surfaces (81) extending beyond the cup filling area; filling the cup filling area with a pasty product; placing on the free surface of the pasty product (11) the second sheet cut so as to form a lid (13); and sealing the lid (13) on the side surfaces (81). Before shaping the first sheet (4) by folding, the sheet (4) is heated at selected areas (5) so as to carry out thermoforming during the folding operation.