Lyocell Smoking Filter Composition for Hardness and Compostability

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Solution Overview

Problem

Existing cigarette filters made from cellulose acetate or lyocell tow face challenges in achieving both adequate hardness and biodegradability under industrial composting conditions, with cellulose acetate filters being difficult to compost and lyocell filters lacking hardness when not supplemented with synthetic binders, which compromise biodegradability.

Innovation Solution

A smoking article filter comprising lyocell tow with a phenol reducing material, such as polyethylene glycol (PEG), triethyl citrate (TEC), or triacetin (TA), and a nonporous filter wrapper with a high basis weight to maintain hardness while ensuring excellent disintegrability and biodegradability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a plasticizer is applied to CA tow to improve hardness, then the bonding strength between fibers increases and hardness is improved, but disintegrability under industrial composting conditions decreases

Engineering Contradiction:
ImprovehardnessVSAvoiddisintegrability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent changes the chemical composition parameters by replacing synthetic plasticizers with natural plasticizers (glycerin, sorbitol, or xylitol) and adjusting the ratio of lyocell fiber to binder. This parameter change allows the filter to achieve adequate hardness while maintaining disintegrability under industrial composting conditions, as the natural plasticizers decompose more readily than synthetic ones.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite material system combining lyocell fiber with natural plasticizers and controlled binder content. This composite structure provides the necessary mechanical strength through the fiber-plasticizer matrix while allowing controlled disintegration through the biodegradable nature of the components under composting conditions.

Inventive Principle:
Principle #40Composite materials

2Strength

If a synthetic binder is applied to L-tow to impart hardness, then hardness is improved, but disintegrability and biodegradability decrease

Engineering Contradiction:
ImprovehardnessVSAvoidbiodegradability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent reduces the binder content parameter to 5-20 wt% of total filter weight and replaces synthetic binders with natural alternatives. This parameter change maintains sufficient hardness through optimized fiber packing and natural plasticizer action while ensuring complete biodegradability, as the reduced and natural binder content decomposes fully under industrial composting conditions.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs a disposable filter design where the entire filter structure, including the binder, is intended to decompose completely after use. The binder is formulated to be biodegradable and fully compostable, aligning with the disposable nature of smoking filters while ensuring environmental compatibility through complete disintegration under industrial composting conditions.

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

3Reliability

If no plasticizer is used in L-tow filters, then biodegradability is maintained, but hardness becomes insufficient

Engineering Contradiction:
ImprovebiodegradabilityVSAvoidhardness
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent introduces natural plasticizers (glycerin, sorbitol, or xylitol) as intermediary substances that mediate between the lyocell fibers. These plasticizers act as binding agents that provide sufficient hardness through their plasticizing effect on the cellulose fibers while maintaining biodegradability, as they are natural compounds that decompose readily under industrial composting conditions.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent optimizes the plasticizer concentration parameter and selects specific natural plasticizer compounds to achieve the desired hardness. By controlling the plasticizer content and type, the filter achieves adequate mechanical strength through enhanced fiber flexibility and bonding while maintaining complete biodegradability through the natural decomposition of the plasticizer molecules.

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 improves phenol reducing performance, maintains filter hardness, and enhances disintegrability to 80% or more under industrial composting conditions, thereby improving biodegradability.

Implementation Method 1

an additive, which is a phenol reducing material, added to lyocell tow, thereby improving phenol reducing performance

Methodology Applied
Scientific EffectPhenol reducing: Absorption (physical)

Implementation Method 2

excellent disintegrability under industrial composting conditions (EN 13432), and thus having improved biodegradability

Methodology Applied
Scientific EffectBiodegradation: Decomposition (biological)

Data Source

PatentEP4699458A1Bio-disintegrable and eco-friendly filter for smoking article
Publication Date: 2026.02.25 KT&G CO LTD
  • EP4699458A1 patent drawingFigure 1
  • EP4699458A1 patent drawingFigure 2(a)~2(d)
  • EP4699458A1 patent drawingFigure 3(a)~3(d)

AI summary

Provided are a smoking article filter and a smoking article including the same. The smoking article filter includes lyocell tow including lyocell fibers. wherein, after three months (twelve weeks) under industrial composting conditions including a temperature of 58 °C±2 °C and a humidity of 50%±2% according to EN 13432, the smoking article filter has a disintegrability of 80% or more, and the disintegrability is defined by the mathematical equation below. D=m1−m2m1×100 (Here, D represents disintegrability (%), m1 represents an initial weight (g) of the smoking article filter, and m2 represents a weight (g) of a residue at an upper end of a standard sieve after the period.)