Bio-Based Wrapping Paper With Layered Waterproof and Oil-Proof Coatings

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Solution Overview

Problem

Current waterproof and oil-proof wrapping papers face challenges in achieving excellent properties while being environmentally friendly, degradable, and non-toxic, with existing solutions often causing harm to the human body and environment.

Innovation Solution

A bio-based waterproof and oil-proof wrapping paper is developed using a double-layer oil-proof coating and a single-layer waterproof coating, with natural bio-based polymers such as sodium alginate and chitosan, combined with nanoparticles and biological waxes, to enhance mechanical strength and hydrophobic effects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If fluorine-containing substances are used in wrapping paper to provide waterproof and oil-proof effects, then the waterproof and oil-proof performance is improved, but the harm to human body and environment increases

Engineering Contradiction:
Improvewaterproof and oil-proof performanceVSAvoidharm to human body and environment
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters by replacing fluorine-containing substances with natural bio-based polymers (sodium alginate, chitosan) and biological waxes. This parameter substitution maintains the waterproof and oil-proof functionality while eliminating the harmful effects of fluorine compounds, achieving both performance and safety requirements

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite materials by combining multiple natural components: sodium alginate provides water resistance, chitosan contributes to oil resistance, and biological waxes enhance both properties. This composite approach using naturally derived materials achieves the required protection levels without the toxicity associated with synthetic fluorine-based coatings

Inventive Principle:
Principle #40Composite materials

2Reliability

If petroleum-based polymers such as polyethylene and polypropylene are used to provide waterproof and oil-proof effects, then the waterproof and oil-proof performance is improved, but environmental pollution and resource consumption increase

Engineering Contradiction:
Improvewaterproof and oil-proof performanceVSAvoidenvironmental pollution and resource consumption
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent fundamentally changes the material source parameter from petroleum-based synthetic polymers to bio-based natural polymers. Sodium alginate is derived from seaweed, chitosan from crustacean shells, and waxes from plant sources. This parameter change enables biodegradability and reduces dependence on fossil fuels while maintaining protective performance

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent adopts a disposable approach with biodegradable materials. The wrapping paper designed with natural polymers and waxes can be used once and then decomposed naturally, eliminating the long-term environmental persistence problem of petroleum-based plastics. This aligns with the disposable principle by using inexpensive, readily available natural materials that serve their purpose and then break down harmlessly

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Object-generated harmful factors

If polylactic acid is used as a biodegradable material to replace plastic wrapping, then environmental friendliness is improved, but mechanical strength and processability worsen due to fragility and high crystallinity

Engineering Contradiction:
Improveenvironmental friendlinessVSAvoidmechanical strength
Core Design Contradiction:
Object-generated harmful factorsVSStrength

Solution Approach 1:

The patent creates a composite structure where the base paper provides mechanical strength and the multi-layer coating system (sodium alginate, chitosan, biological waxes) provides protective functions. This composite approach allows each component to contribute its strengths: the paper substrate maintains structural integrity while the natural polymer coatings provide waterproof and oil-proof properties without the brittleness issues of pure PLA

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies different materials with specific local functions: sodium alginate primarily for water resistance, chitosan for oil resistance, and biological waxes for enhanced barrier properties. This local specialization of material functions allows the overall structure to achieve high performance while maintaining biodegradability, avoiding the need for high-crystallinity materials like PLA that compromise flexibility

Inventive Principle:
Principle #3Local quality

4Reliability

If polyhydroxyalkanoate is used as a biodegradable material with excellent waterproof property, then environmental friendliness and waterproof performance are improved, but thermal instability and difficult processability worsen

Engineering Contradiction:
Improvewaterproof propertyVSAvoidprocessability
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent changes the formulation parameters by using aqueous solutions of sodium alginate and chitosan with controlled concentrations and molecular weights. The coating solutions are prepared with specific solid contents and applied at controlled conditions, enabling easy processing without the thermal instability problems of PHA. The natural polymers can be processed at lower temperatures with simpler equipment

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 paper achieves an oil-proof level of 8 or greater, low water vapor transmission rate, high tensile strength, and is completely biodegradable and harmless to the environment and human body.

Implementation Method 1

impregnating base paper in a calcium chloride solution

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 2

impregnating base paper in a calcium chloride solution

Methodology Applied
Scientific EffectIonic interaction: Ion Repulsion/Attraction

Implementation Method 3

coating a surface of the calcium chloride pretreated base paper with the sodium alginate solution, followed by drying

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 4

mixing an acetic acid aqueous solution, chitosan, a plasticizer and a crosslinking agent uniformly to obtain a chitosan solution

Methodology Applied
Scientific EffectCrosslinking: Chemical Bonding

Implementation Method 5

coating a surface of the single-layer oil-proof paper with the chitosan solution, followed by drying

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 6

mixing an acetic acid aqueous solution, chitosan, a plasticizer and a crosslinking agent uniformly to obtain a chitosan solution

Methodology Applied
Scientific EffectCrosslinking: Chemical Bonding

Implementation Method 7

coating a surface of the double-layer oil-proof paper with the biological wax-nanoparticle solution, followed by drying

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 8

adding nanoparticles into a biological wax solution to obtain a biological wax-nanoparticle solution

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 9

The surface of the paper is provided with a double-layer oil-proof coating and a single-layer waterproof coating, ensuring that the paper has a better oil-proof level and water resistance

Methodology Applied
Scientific EffectHydrophobic effect: Hydrophobe

Data Source

PatentUS12344996B2Bio-based waterproof and oil-proof wrapping paper and preparation method thereof
Publication Date: 2025.07.01 JIANGNAN UNIV

AI summary

The present disclosure discloses a bio-based waterproof and oil-proof wrapping paper and a preparation method thereof, and belongs to the field of waterproof and oil-proof papers. The method for preparing the waterproof and oil-proof wrapping paper in the present disclosure includes: (1) impregnating base paper in a calcium chloride solution, taking out the base paper, and drying the base paper; (2) mixing sodium alginate, a plasticizer and water uniformly to obtain a sodium alginate solution; mixing an acetic acid aqueous solution, chitosan, a plasticizer and a crosslinking agent uniformly to obtain a chitosan solution; then coating a surface of the calcium chloride pretreated base paper with the sodium alginate solution, followed by drying to obtain a single-layer oil-proof paper; and then coating a surface of the single-layer oil-proof paper with the chitosan solution, followed by drying to obtain a double-layer oil-proof paper; and (3) adding nanoparticles into a biological wax solution; and then coating a surface of the double-layer oil-proof paper with the biological wax-nanoparticle solution, followed by drying to obtain the waterproof and oil-proof paper.