Helical Thread Roller Profile for Filter Strip Stretching
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Solution Overview
Problem
Existing equipment for processing filter material strips in the tobacco industry causes damage to the fibers during longitudinal and transverse pulling or stretching operations, leading to adverse effects on filtration properties.
Innovation Solution
The equipment employs a pair of rollers with a helical thread on one roller and a resiliently faced anvil roller, where the active portions of the thread are flat and rounded, ensuring minimal contact damage and promoting homogeneous stretching without splits or cuts, combined with guide rollers to manage the strip's path effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If longitudinal and transverse pulling or stretching operations are performed using threaded rollers and anvil rollers, then the strip of filter material is stretched and pulled to achieve desired dimensions and homogeneity, but the constituent fibres of the strip suffer damage and rupture which adversely affects filtration properties
Solution Approach 1:
The invention changes the geometric parameters of the roller surfaces from conventional sharp-edged threads to rounded profiles with specifically controlled radius of curvature (R1, R2, R3). This parameter modification allows the stretching operation to proceed without fibre rupture, achieving both homogeneity and fibre integrity by eliminating stress concentration points that cause damage in traditional designs
Solution Approach 2:
The invention applies curvature to the roller surfaces by providing rounded active portions instead of sharp edges. The threaded roller features crests with rounded profiles and the anvil roller has corresponding rounded grooves, creating a curved contact interface that distributes stress evenly across the strip width, preventing fibre rupture while maintaining effective stretching and homogenization
2Productivity
If conventional threaded rollers with sharp-edged threads are used for stretching, then stretching operation is effective, but splits and cuts occur in the strip
Solution Approach 1:
The invention replaces sharp-edged threads with rounded profiles having controlled radius of curvature. The threaded roller crests and anvil roller grooves both feature rounded surfaces that eliminate stress concentration points, allowing the stretching operation to proceed without causing splits or cuts while maintaining stretching efficiency through proper geometric design
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
This solution allows for the production of filters with improved filtration coefficients by maintaining the integrity of the filter material, resulting in more homogeneous and robust structures with enhanced filtration performance.
Implementation Method 1
an anvil roller 12 of which the axis 12a lies parallel to the former axis 11 a. The outer cylindrical surface of the top roller 11 presents a helical thread 15, whilst the anvil roller 12 is faced with resilient material.
Data Source
Figure 1~8
Figure 2~3
Figure 4~5
AI summary
A strip (2) of material used to make filter tips is processed on equipment incorporating one or more pairs of rollers (11, 12, 13, 14) placed along a set path (P) , each composed of a top roller (11, 13) with a helical thread (15) , and an anvil roller (12, 14) , by which the fibres of the strip (2) are stretched and pulled longitudinally and/or transversely; when seen in section, the profile (16) of the helical thread (15) is such that each turn presents a crest portion (17) merged with two flanks (19) by way of smooth and/ or rounded portions (20) , so that when the strip (2) of filter material is engaged by the crest portion (17) , it will not be brought into contact with sharp corner edges.