Paper Cigarette Filter Structure for Uniform Holes and Appearance

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Solution Overview

Problem

Cellulose acetate filters are poorly biodegradable and crimped paper filters with irregular holes deteriorate the exterior appearance of smoking articles.

Innovation Solution

A tobacco filter made from a paper sheet with specific bulk, coarseness, and air permeability, using pulp fibers including single and mixed fibers, ensures a regular cross-sectional shape and uniform holes, enhancing biodegradability and appearance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a crimped paper filter is applied to the mouth end of a smoking article, then biodegradability is improved, but exterior appearance deteriorates due to irregular or uneven holes between the folds

Engineering Contradiction:
ImprovebiodegradabilityVSAvoidexterior appearance
Core Design Contradiction:
ReliabilityVSShape

Solution Approach 1:

The patent applies parameter changes by controlling the bulk of the paper sheet within a specific range (1.5 to 3.0 cm³/g) to achieve both uniform hole structure and regular cross-sectional shape. This parameter optimization resolves the contradiction by transforming the paper structure to maintain appearance quality while preserving biodegradability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials by combining pulp fiber and regenerated fiber in a specific weight ratio (pulp fiber: regenerated fiber = 9:1 to 5:5). This composite structure enables the paper sheet to form uniform holes and regular cross-sections when crimped, while maintaining biodegradability from the pulp fiber component

Inventive Principle:
Principle #40Composite materials

2Reliability

If a paper filter is used as an alternative to cellulose acetate filter, then biodegradability is improved, but exterior appearance deteriorates due to irregular holes between folds

Engineering Contradiction:
ImprovebiodegradabilityVSAvoidexterior appearance
Core Design Contradiction:
ReliabilityVSShape

Solution Approach 1:

The patent optimizes the bulk parameter of the paper sheet (1.5 to 3.0 cm³/g) to achieve uniform hole distribution and regular cross-sectional shape when crimped. This parameter control resolves the appearance issue while maintaining the biodegradable nature of the paper filter

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite fiber structure combining pulp fiber and regenerated fiber in controlled proportions. This composite approach enables the paper to form uniform holes and regular shapes during crimping, eliminating the appearance defects of conventional paper filters while preserving biodegradability

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP4706415A1Cigarette filter and smoking article comprising same
Publication Date: 2026.03.11 KT&G CO LTD
  • EP4706415A1 patent drawingFigure 1~2
  • EP4706415A1 patent drawingFigure 3~4
  • EP4706415A1 patent drawingFigure 5~7

AI summary

Disclosed is a cigarette filter having a beautiful external appearance. According to one aspect, the cigarette filter comprises a paper sheet including pulp fibers, wherein the bulk of the paper sheet is 2 to 4 cm3/g. The pulp fibers include at least one among: single fibers having an average coarseness of 13 mg/100 m or more; and mixed fibers including sub-pulp fibers and regenerated fibers.