Eco-Friendly Paper Cup Base Paper Double-Coating Method

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Solution Overview

Problem

Existing base papers for paper cups lack biodegradability, recyclability, and simultaneously achieve optimal heat sealability, water resistance, and block resistance, leading to manufacturing difficulties and environmental issues.

Innovation Solution

A method for manufacturing a base paper with a double-coating layer, comprising a first coating layer for heat sealability and water resistance, and a second coating layer for block resistance, using specific resins and additives to optimize properties and prevent bubbling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If polyethylene (PE) coating is used to ensure heat sealability and water resistance, then heat sealability and water resistance are improved, but biodegradability and recyclability deteriorate

Engineering Contradiction:
Improveheat sealabilityVSAvoidbiodegradability
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters of the coating material from polyethylene to polylactic acid (PLA), transforming it from a non-biodegradable petroleum-based polymer to a biodegradable bio-based polymer. This parameter change maintains heat sealability and water resistance while enabling biodegradability and improving recyclability through natural pulp recovery processes.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite material structure by combining PLA coating with paper base material, creating a composite that exhibits both the functional properties of PLA (heat sealability, water resistance, biodegradability) and the structural properties of paper (recyclability through pulping). The composite enables eco-friendly paper cups to meet both performance and environmental requirements.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If polylactic acid (PLA) coating is used to improve biodegradability, then biodegradability is improved under specific conditions, but heat sealability and water resistance deteriorate

Engineering Contradiction:
ImprovebiodegradabilityVSAvoidheat sealability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent optimizes the molecular weight, crystallinity, and composition parameters of the PLA coating material to achieve a balance between biodegradability and functional performance. By controlling these parameters, the PLA coating maintains adequate heat sealability and water resistance while preserving its biodegradable characteristics under composting conditions.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If PLA coating is applied to ensure water resistance, then water resistance is improved, but manufacturing complexity and cost increase due to difficult pulp recovery

Engineering Contradiction:
Improvewater resistanceVSAvoidrecycling process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent enables the PLA coating to be automatically recovered during the natural pulping process without requiring separate removal steps. The coating dissolves and separates in the pulp slurry during recycling, allowing the paper fibers to be recovered and reused while the PLA coating is removed through the self-service mechanism of the pulping process itself, reducing manufacturing complexity.

Inventive Principle:
Principle #25Self-service

4Reliability

If heat sealability is increased to ensure proper sealing, then sealing quality is improved, but block resistance deteriorates causing sticking between cups

Engineering Contradiction:
Improveheat sealabilityVSAvoidblock resistance
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies different properties to different regions or aspects of the coating: the coating composition and structure are designed to provide high heat sealability at the sealing interface while maintaining lower surface adhesion properties in other areas. This local quality differentiation ensures proper sealing during manufacturing while preventing unwanted sticking between finished cups during storage and handling.

Inventive Principle:
Principle #3Local quality

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 method produces a base paper with enhanced heat sealability, water resistance, and block resistance, enabling easy molding, recyclability, and biodegradability, while preventing sticking and reducing production costs.

Implementation Method 1

a base paper for paper cups, a coated surface of which is adhesively bonded to another base paper or another coated surface

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

excellent heat sealability, water resistance, and block resistance... heat sealing between a coated surface and a paper and heat sealing between a coated surface and a coated surface

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentEP3904595B1Method for manufacturing raw paper for eco-friendly paper cup
Publication Date: 2026.03.25 HANKUK PAPER MFG
  • EP3904595B1 patent drawingFigure 1~3
  • EP3904595B1 patent drawingFigure 4~5
  • EP3904595B1 patent drawingFigure 6~7

AI summary

Disclosed is a method for manufacturing a base paper for eco-friendly paper cups and, more specifically, to a method for manufacturing a base paper for eco-friendly paper cups, the method enabling the manufacturing of a base paper for eco-friendly cups, which has excellent heat sealability, water resistance, and block resistance, facilitates recycling, and is biodegradable in nature.