Cigarette Wrapping Asymmetric Folding to Prevent Tobacco Damage
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Solution Overview
Problem
Conventional methods for wrapping cigarettes in airtight materials often damage the cigarettes during folding and heat sealing, leading to deformation and exposure to atmospheric conditions that can alter the tobacco's organic characteristics, especially when using thicker, stiffer materials and high-pressure heat sealing.
Innovation Solution
A wrapping method and unit that folds a sheet of airtight, heat-seal plastic material asymmetrically around cigarettes, using a wrapping wheel with suction and folding mechanisms to minimize mechanical stress and apply heat sealing between metal parts, ensuring a high-quality seal without damaging the cigarettes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sheet of airtight heat-seal plastic material is used to wrap cigarettes, then the tobacco is better preserved by preventing atmospheric exposure, but the thickness and stiffness of the material cause damage to cigarette ends during folding and heat sealing
Solution Approach 1:
The sheet is folded into multiple separate flaps (first flap, second flap, third flap, fourth flap) that wrap around the cigarette group independently. This segmentation allows each flap to be folded and sealed separately, distributing the mechanical stress and reducing damage to individual cigarettes compared to a single large fold.
Solution Approach 2:
Instead of folding the thick stiff sheet directly onto the cigarettes causing damage, the method inverts the approach by first folding thinner conventional foil material onto the cigarettes, then placing the airtight sheet over this protective layer. This inversion protects cigarettes from direct contact with the stiff airtight material during folding.
2Productivity
If high-pressure heat sealing is applied to achieve a good-quality airtight seal quickly, then the sealing speed meets modern packing machine requirements (500 packets per minute), but the pressure and temperature transmitted to cigarettes cause permanent deformation and overheating of tobacco
Solution Approach 1:
The heat sealing process is segmented into multiple separate sealing zones corresponding to each flap (first, second, third, and fourth sealing zones). This allows the sealing load to be distributed across multiple locations and time points rather than applying high pressure to all seams simultaneously, reducing the risk of cigarette deformation while maintaining overall sealing speed.
Solution Approach 2:
The cigarettes are first wrapped in a layer of conventional foil material before applying the airtight heat-seal plastic sheet. This preliminary wrapping creates a protective barrier that cushions the cigarettes during subsequent high-pressure heat sealing operations, preventing direct transmission of damaging forces and temperatures to the tobacco.
3Shape
If folding lines are created in the sheet to wrap around the cigarette group, then the sheet can be formed into a packet shape, but the fold lines cause localized deformation and tobacco spill from cigarettes located along the fold lines
Solution Approach 1:
The wrapping sheet is divided into multiple flaps with separate fold lines positioned at different locations around the cigarette group. This segmentation distributes the folding stress across multiple gentle bends rather than concentrating it in single sharp fold lines, reducing localized deformation and preventing tobacco spill from cigarettes at any single fold location.
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 effectively prevents damage to cigarettes during folding and heat sealing, maintaining the integrity of the tobacco by reducing mechanical stress and ensuring a high-quality, airtight seal compatible with fast-operating packing machines.
Implementation Method 1
wrapping wheel with suction and folding mechanisms
Implementation Method 2
heat sealing the superimposed portions of the sheet of inner wrapping material
Data Source
AI summary
A method and unit for folding a sheet of wrapping material about a group of cigarettes includes feeding the cigarettes and wrapping material into a pocket of a wrapping conveyor so the sheet of wrapping material folds into a U inside the pocket and has an outer end projecting from the pocket, and an inner end resting on a lateral wall of the cigarettes. The method also includes folding the inner end 90° so the inner end is perpendicular to the lateral wall. The method also includes folding the outer end into an L inside the pocket, onto the lateral wall of the cigarettes and onto the inner end perpendicular to the lateral wall so as to superimpose the outer end and the inner end and impart a tubular shape to the sheet of wrapping material. The method also includes heat sealing the outer and inner ends together.