Double Wrapper Cigarette Manufacturing via Rod Segmentation

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Solution Overview

Problem

The existing method for making filtered cigarettes with a double wrapper structure faces challenges in accurately attaching inner patches at high speeds, leading to variations in patch position and quality issues due to web extension caused by pulling forces and ambient temperature.

Innovation Solution

The method involves forming a cigarette rod twice the length of a filtered cigarette, cutting it into two equal lengths, turning them around, placing a filter plug between, wrapping with double tip paper, and cutting to form individual cigarettes, with outer wrappers wrapped equally distanced from the axial center to stabilize the double wrapper structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the web travels at extremely high speed to match cigarette making rate, then productivity increases, but manufacturing precision deteriorates due to difficulty in accurately attaching inner patches

Engineering Contradiction:
Improvecigarette making rateVSAvoidinner patch attachment position accuracy
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The process is divided into two independent stages: first forming the cigarette rod with wrapper at reduced speed for precise inner patch attachment, then later cutting and assembling with filter at high speed. This segmentation allows each stage to operate at optimal speed without compromising precision or productivity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The inner patches are attached to the web in advance during the cigarette rod forming stage at lower speed, ensuring precise positioning before the high-speed cutting and filter assembly stage. This preliminary action at controlled speed resolves the contradiction between high productivity and positioning accuracy.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If the web is allowed appropriate extension to enable high-speed traveling and prevent breaking, then productivity increases, but manufacturing precision deteriorates due to variation in inner patch position

Engineering Contradiction:
Improveweb traveling speedVSAvoidinner patch position consistency
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The system dynamically adjusts web tension based on the operational phase: maintained taut during high-speed travel and cutting for productivity, and relaxed during the inner patch attachment phase for precision. This dynamic control allows the web to accommodate both high-speed operation and precise positioning requirements.

Inventive Principle:
Principle #15Dynamics

3Ease of manufacture

If outer wrapper is wrapped around cigarette rod subjected to axial pulling force, then ease of manufacture increases, but manufacturing precision deteriorates due to wrapper extension affecting wrapping position

Engineering Contradiction:
Improvewrapper wrapping processVSAvoidwrapper wrapping position accuracy
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The outer wrapper is attached in advance to the cigarette rod during the low-speed forming stage before axial pulling forces are applied in later high-speed processing stages. This preliminary attachment ensures the wrapper is positioned accurately before any forces that might cause extension are applied.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The cigarette rod structure is designed to cushion and distribute axial pulling forces, preventing these forces from causing extension or displacement of the newly attached outer wrapper. This beforehand cushioning protects the precision of the wrapper attachment during subsequent high-speed handling.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentEP3231300B1Method for manufacturing filtered cigarette
Publication Date: 2020.11.04 JAPAN TOBACCO INC
  • EP3231300B1 patent drawingFigure 1
  • EP3231300B1 patent drawingFigure 2
  • EP3231300B1 patent drawingFigure 3~4

AI summary

The method of making filtered cigarettes according to the present invention includes steps of: wrapping an outer wrapper (X) around a cigarette rod (CR) of twice the length of a cigarette at the center, then cutting the cigarette rod (CR) with the outer wrapper (X) into two cigarettes (C), then turning the two cigarettes around, respectively, and then forming two filtered cigarettes using the turned-around two cigarettes (C) by a publicly-known process.