Food Packaging Bag Grease Barrier Flap Design

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Solution Overview

Problem

Conventional paper packaging bags for food products are prone to grease penetration, leading to aesthetic degradation and loss of mechanical resistance, especially at the edges where capillary action allows fats to soak through, posing storage issues and requiring costly or risky additional treatments like PFAS or wax coatings.

Innovation Solution

A packaging bag design featuring a film with a paper outer layer and a grease barrier inner layer, where the longitudinal edge of the barrier layer projects beyond the paper layer to form a flap that is glued inside the bag, preventing direct contact with food products and thus reducing grease absorption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a paper bag is used for food packaging, then it is ecological and economical, but grease penetrates through the paper edges by capillary action causing aesthetic degradation and loss of mechanical resistance

Engineering Contradiction:
Improveecological and economicalVSAvoidgrease resistance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The bag is divided into two functional layers: a paper layer for ecological and economical benefits, and a barrier layer (flap) for grease resistance. The barrier layer is segmented to extend specifically to the edges where grease penetration occurs, creating a functional division that addresses both requirements simultaneously.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention uses a composite structure combining paper material with a barrier material (such as plastic or metalized layer). This composite film structure allows the bag to maintain the ecological advantages of paper while adding grease barrier properties through the extended barrier layer flap that seals the edges.

Inventive Principle:
Principle #40Composite materials

2Reliability

If PFAS or wax coatings are applied to the film during manufacture, then grease resistance is improved, but the process becomes costly and introduces additional risks of grease penetration

Engineering Contradiction:
Improvegrease resistanceVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Instead of treating the entire film with complex coatings during manufacture, the invention extracts the grease barrier function to a specific component - the barrier layer flap that extends to the edges. This eliminates the need for complex PFAS or wax coating processes while maintaining grease resistance where it is most needed.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The grease barrier property is applied locally rather than uniformly across the entire bag. The barrier layer extends specifically to the longitudinal edges where capillary action causes grease penetration, providing targeted protection without requiring complex manufacturing processes for full-surface coating.

Inventive Principle:
Principle #3Local quality

3Reliability

If the barrier layer extends beyond the paper layer to form a flap, then grease penetration is prevented, but the structural complexity of the film increases

Engineering Contradiction:
Improvegrease resistanceVSAvoidfilm structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The film is segmented into two distinct layers with different functions: the paper layer provides structural integrity and ecological benefits, while the barrier layer extends to form a flap that specifically addresses grease penetration. This segmentation creates a simple yet effective structure that prevents grease contact with the paper edges.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The barrier layer is extended in the longitudinal dimension beyond the paper layer edges, creating a flap that seals the edge area. This dimensional extension provides a simple geometric solution to prevent grease penetration without requiring complex multi-layer stacking or intricate structural designs.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 solution effectively prevents grease from soaking into the paper, maintaining the bag's aesthetic and mechanical integrity while being economical and ecological, with the barrier layer representing only a maximum of 2% of the material, ensuring the bag remains resistant to fats during the shelf life of the packaged products.

Implementation Method 1

the same problem arises at the level of the slices of the film constituting the bag which allows the fats to penetrate by capillarity

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Data Source

PatentEP4420870A1Fat-resistant packaging bag for food products and method for making same
Publication Date: 2024.08.28 COVERIS FLEXIBLES FRANCE
  • EP4420870A1 patent drawingFigure 1~2
  • EP4420870A1 patent drawingFigure 3~4
  • EP4420870A1 patent drawingFigure 5~6

AI summary

The invention relates to a method for manufacturing a food packaging bag (1) from a film (2) folded, cut and continuously glued/sealed to form a sheath (3) defining a front wall (3a), a back wall (3b), a bottom (4), and a filling opening (5), the film (2) being in the form of a complex comprising on its outer face a layer of paper (2a) and on its inner face a grease barrier layer (2b), characterized in that it consists of using a film (2) in which a longitudinal edge of the barrier layer (2b) extends beyond a longitudinal edge of the paper layer (2a) along a longitudinal edge of the sheath (3) so as to define a flap (2b1) of the barrier layer, free or folded and glued onto the paper layer (2a), and, during the formation of the sheath (3),to glue the flap (2b1) to the inside (I) of the sleeve (3) to prevent any contact between the longitudinal edge of the paper layer (2a) and the products intended to be packaged in the bag.