Bread Bag Coating Inversion and Masking for Moisture Control

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Solution Overview

Problem

Conventional bread bags with vegetable or mineral oil coatings suffer from aesthetic issues due to excessive spreading and permeation, which affects their moisture permeability and recyclability standards.

Innovation Solution

A bread bag design featuring a cellulose layer with a more closed structure on one side and a coating layer on the inner side, accompanied by a masking layer with a predetermined pattern, which limits the coating's permeation and provides aesthetic appeal while maintaining recyclability and compostability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a coating layer of vegetable oil is applied to the outer side of the bread bag, then the bread bag meets recyclability and compostability requirements, but the coating spreads out too much and permeates the paper, resulting in poor aesthetic appearance

Engineering Contradiction:
Improverecyclability and compostabilityVSAvoidaesthetic appearance
Core Design Contradiction:
ReliabilityVSShape

Solution Approach 1:

The patent applies the coating layer to the inner side of the bread bag instead of the outer side, inverting the conventional approach. This prevents the coating from spreading and permeating the paper in a visible manner while still providing the necessary moisture barrier and maintaining recyclability and compostability.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent introduces a masking layer as an intermediary between the cellulose layer and the coating layer. This masking layer has a predetermined pattern and controls where the coating layer can spread, creating aesthetic patterns while limiting excessive permeation. The masking layer acts as a mediator that balances aesthetic requirements with functional coating application.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a coating layer is applied to the bread bag to set moisture permeability, then moisture control is improved, but the quantity of additives increases, potentially exceeding regulatory limits for monomaterial status

Engineering Contradiction:
Improvemoisture permeability controlVSAvoidquantity of additives
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The masking layer creates local variations in the bread bag structure, with patterned areas that control coating spread. This allows the coating to be applied more efficiently with reduced overall quantity, as the masking layer directs the coating only where needed rather than requiring uniform thick application across the entire surface.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses partial action by applying the coating layer through a masking layer that covers only portions of the surface. This reduces the total quantity of coating material needed while still achieving adequate moisture permeability control in the critical areas, helping to stay within regulatory additive limits for monomaterial status.

Inventive Principle:
Principle #16Partial or excessive action

3Reliability

If the coating layer is applied with sufficient thickness to ensure moisture barrier properties, then moisture protection is improved, but the coating spreads out more and permeates the paper excessively

Engineering Contradiction:
Improvemoisture barrier propertiesVSAvoidcoating spread control
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The masking layer serves as an intermediary that controls the spread of the coating layer. It allows the coating to be applied with sufficient thickness for moisture barrier properties while preventing excessive lateral spread and permeation, as the masking layer's patterned structure confines the coating to specific areas.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the physical parameters of the coating application by using a masking layer with specific pattern geometry and material properties. This modifies how the coating spreads, allowing controlled thickness in protected areas while limiting spread to pattern boundaries, thus achieving moisture barrier properties without excessive permeation.

Inventive Principle:
Principle #35Parameter changes

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 results in an aesthetically attractive bread bag with controlled moisture permeability, meeting recyclability and compostability standards, and reduces the quantity of additives required, aligning with regulatory requirements for 'monomaterial' status.

Implementation Method 1

This effect is based on the fact that the masking layer obstructs the oily material of the coating layer and that the paper retains its original colour at the position of the masking layer.

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Implementation Method 2

The partial penetration of the oily material of the coating layer into the cellulose layer has been found to produce an increase in the transparency of the paper in a uniformly distributed manner.

Methodology Applied
Scientific EffectPermeation: Permeation

Data Source

PatentEP3702529A1Bread bag and method for manufacture thereof
Publication Date: 2020.09.02 ACE PACKAGING
  • EP3702529A1 patent drawingFigure 1A~2
  • EP3702529A1 patent drawingFigure 3
  • EP3702529A1 patent drawing

AI summary

Bread bag of combined layers comprising a cellulose layer and a coating layer for setting the moisture permeability, wherein the cellulose layer has a more closed structure on a first side than on an opposite, second side, and wherein the coating layer is situated on the first side of the cellulose layer, wherein the coating layer is situated on an inner side of the bread bag, and a masking layer is present on the second side of the cellulose layer, which masking layer is provided with a predetermined pattern.