Sliver Drawing With Carding Roller Control for Fiber Continuity

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Solution Overview

Problem

Existing air spinning systems face limitations in fiber parallelization efficiency and maximum drawing capacity at high speeds, leading to poor yarn quality due to the presence of short fibers and discontinuity in fiber flow.

Innovation Solution

A drawing method using a carding roller with specific tooth configuration and counter-rotating extraction cylinder to draw fibers progressively and continuously, ensuring minimal fiber breakage and continuity, achieved by setting the carding roller's speed equal to the product of sliver input speed and total drawing ±20%, with teeth arranged at a wider pitch and vacuum-assisted fiber detachment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If traditional drawing systems with multiple pairs of drawing and pressure cylinders are used, then progressive drawing of the sliver is achieved, but fiber parallelization efficiency deteriorates at high working speeds

Engineering Contradiction:
Improveworking speedVSAvoidfiber parallelization efficiency
Core Design Contradiction:
SpeedVSManufacturing precision

Solution Approach 1:

The patent replaces the traditional mechanical drawing system with multiple pairs of drawing and pressure cylinders with a carding roller system that uses the mechanical action of teeth to tear fibers from the sliver. This substitution enables effective fiber parallelization at high speeds by utilizing the centrifugal action and tooth engagement mechanism instead of progressive mechanical compression and drawing.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If traditional drawing systems are used, then drawing of the sliver is performed, but maximum obtainable drawing is limited

Engineering Contradiction:
Improvemaximum obtainable drawingVSAvoidfiber distribution homogeneity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent changes the operational parameters by using a carding roller with specific tooth configurations (number, shape, pitch) and controlling the peripheral speed of the carding roller relative to the sliver feed speed. This allows achieving higher maximum drawing ratios while maintaining fiber distribution homogeneity through the controlled mechanical action of the teeth on the fibers.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If carding roller systems are used with high rotation speed, then impurities and short fibres are removed, but fiber flow continuity is disrupted

Engineering Contradiction:
Improvefiber flow continuityVSAvoidcentrifugal action effectiveness
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies preliminary action by using the carding roller teeth to gradually tear and detach fibers from the sliver in a controlled manner before they enter the high-speed centrifugal separation zone. This preliminary mechanical action prepares the fiber flow for subsequent centrifugal purification while maintaining continuity, as the teeth progressively engage and release fibers rather than abrupt removal.

Inventive Principle:
Principle #10Preliminary 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

Ensures high-quality yarn production with longer fibers and reduced breakage risk, maintaining fiber continuity and allowing increased working speed and drawing capacity while minimizing production costs.

Implementation Method 1

the centrifugal action due to the high rotation speed to remove impurities and short fibres from the flow of fibres

Methodology Applied
Scientific EffectCentrifugal action: Centrifugal Force

Implementation Method 2

an extraction cylinder provided with a perforated wall adapted to create a negative pressure

Methodology Applied
Scientific EffectVacuum: Vacuum

Data Source

PatentEP3572565B1Drawing method for a sliver
Publication Date: 2025.08.27 SAVIO MACCHINE TESSILI SPA
  • EP3572565B1 patent drawingFigure 1
  • EP3572565B1 patent drawingFigure 2a~3

AI summary

A drawing device (4) for webs (8) of textile fibres comprising - a feeder device (12) of a web (8) to be drawn, - a carding machine (28) rotating according to a direction of rotation (S) comprising, on an outer side wall thereof (32), a plurality of teeth (36) arranged with a constant tangential pitch (P), adapted to draw said web (8), - an extraction cylinder (56) placed downstream of the carding machine (28) and of the web (8), wherein - the feeder device (12) comprises a feeder roller (16), facing the carding machine (28), which rotates so as to feed the web to the carding machine (28) at an input speed and according to a direction of advancement (F) concordant with respect to said direction of rotation (S) of the carding machine (28), - wherein the carding machine is driven in rotation so as to have a peripheral speed on the teeth equal to the product of the input speed times the total drawing of the web ± 20%, so that the drawing of the web takes place practically entirely on the carding machine, - the total drawing being the ratio between the thread count of the yarn to be produced and the input web thread count. [Fig. 1]