Reconstituted Tobacco Sheet Drying for Reduced Cigarette End Loss

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Solution Overview

Problem

Existing methods for producing reconstituted tobacco leaves sheets do not effectively reduce the loss of cigarette ends, which is a significant issue in the tobacco industry.

Innovation Solution

A method involving a drying process with controlled application of hot air at specific temperatures and pressures, along with a pre-drying step, to increase the thickness-to-basis weight ratio of the reconstituted tobacco leaves sheet, enhancing its structural integrity and reducing particle distance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional drying methods are used to produce reconstituted tobacco leaves sheet, then the production process is simple, but the thickness-to-basis weight ratio is insufficient causing cigarette end loss

Engineering Contradiction:
Improvethickness-to-basis weight ratioVSAvoiddrying process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The drying process is divided into two distinct stages: pre-drying at lower temperature (60-80°C) to remove excess water and form preliminary structure, followed by main drying at higher temperature (100-150°C) to achieve final thickness and basis weight ratio. This segmentation allows each stage to optimize for specific parameters, achieving the desired thickness-to-basis weight ratio while controlling overall process complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The pre-drying step performs preliminary water removal and structural formation before the main drying process. By preparing the slurry in advance with controlled moisture content (60-80% of final dry weight), the subsequent main drying process can focus specifically on achieving the target thickness-to-basis weight ratio without requiring excessive overall drying intensity.

Inventive Principle:
Principle #10Preliminary action

2Strength

If the thickness-to-basis weight ratio is increased to reduce cigarette end loss, then the structural integrity improves, but the manufacturing process becomes more complex

Engineering Contradiction:
Improvestructural integrityVSAvoiddrying process complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The drying process employs dynamic temperature adjustment based on the drying stage. The pre-drying stage uses lower temperature (60-80°C) to gently remove water and form structure, while the main drying stage increases temperature (100-150°C) to achieve final structural integrity and desired thickness-to-basis weight ratio. This dynamic approach optimizes structural development at each phase.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The process controls multiple parameters including temperature (60-150°C range), pressure (1.5-3.0 bar), and drying time to achieve the target thickness-to-basis weight ratio. By systematically adjusting these parameters across the two drying stages, the method achieves enhanced structural integrity without requiring overly complex equipment.

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If hot air is applied at high pressure to increase thickness, then the packing density improves, but the energy consumption increases

Engineering Contradiction:
Improvepacking densityVSAvoidenergy consumption
Core Design Contradiction:
Quantity of substanceVSUse of energy by moving object

Solution Approach 1:

The pre-drying stage removes a significant portion of water (to 60-80% of final dry weight) before the main drying process. This preliminary action reduces the total energy required in the main drying stage, as less moisture needs to be removed. The controlled application of hot air at 1.5-3.0 bar during pre-drying efficiently removes water without requiring excessive energy input.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The drying process uses periodic temperature and pressure application in two distinct stages rather than continuous high-temperature high-pressure drying. The pre-drying stage (60-80°C, 1.5-3.0 bar) followed by main drying (100-150°C, 1.5-3.0 bar) creates periodic action that improves energy efficiency compared to sustained high-intensity drying, while still achieving the desired packing density and thickness-to-basis weight ratio.

Inventive Principle:
Principle #19Periodic action

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 increased thickness-to-basis weight ratio results in a denser packing of the tobacco sheet, minimizing cigarette end loss while maintaining the basic performance characteristics of the cigarette, such as weight and suction resistance.

Implementation Method 1

a drying step of applying hot air of 80°C to 150°C to a reconstituted tobacco leaves slurry

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 2

a drying step of applying hot air of 80°C to 150°C to a reconstituted tobacco leaves slurry

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 3

the hot air in the drying step may be applied at a pressure of 1.5 bar to 3.0 bar

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP4696151A1Method for manufacturing reconstituted tobacco sheet for reducing loose ends of cigarettes, and cigarette including reconstituted tobacco sheet manufactured thereby
Publication Date: 2026.02.18 KT&G CO LTD
  • EP4696151A1 patent drawingFigure 1A~1C
  • EP4696151A1 patent drawingFigure 2
  • EP4696151A1 patent drawingFigure 3

AI summary

Provided are a method for producing a reconstituted tobacco leaves sheet including a drying step of applying hot air of 80°C to 150°C to a reconstituted tobacco leaves slurry, and a cigarette containing a reconstituted tobacco leaves sheet produced thereby. The reconstituted tobacco leaves sheet produced by the producing method according to one specific example of the present invention has an increased ratio of thickness to basis weight. In the producing method, controlling a pressure applying hot air or controlling a viscosity by changing a composition of the reconstituted tobacco leaves slurry helps to improve properties of the produced reconstituted tobacco leaves sheet.