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Optimising Spinning Ringframe Conditions

Key Main Machine Variables

Power consumption

End-breakage rate and yarn quality

Production rate

Balloon Control

Lift (balloon height)

Spindle Speed

Ring/Traveller

(Minimising unit cost, maintaining quality)

Maintenance costs

Production rate (kg/h)

NEtex

Vd 601000

1

1000

NEK

texn 60

1000

11

1000

5.1

textK

t

nVd

texK

n

K

texn

tex

Kt

NEK

texn 60

1000

11

1000

5.1

Production rate (kg/h):

Increases with

Spindle speed n

Yarn tex

Machine efficiency E

Number of spindles N

Decreases with twist level K

Ring Spinning Production Calculation Example

Given:Spindle speed: 18,000 rpmYarn linear density: 36 tex

Twist factor: 36 turnscm-1tex1/2Machine efficiency: 90%

Production rate: 100 kg/h

Calculate:

The number of spindles required.

The production rate of the machine

for a 9 tex yarn, all other conditionsremain the same.

Machine efficiency is affected by:End breakage rate

Package size

Yarn tex

Spindle speed

End breakage rate is affected by:

Machine condition

Yarn strength (evenness, fibre, twist, tex)

Yarn tension (spindle speed, balloon size,ring & traveller)

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Spinning Tension Fs

Winding Tension Fw

Balloon Tension Fb Friction Ff

FsFbFw

Ring Spinning YarnTension Analysis

Spinning Triangle

FrontDraftingRollers

To spindle

Main layer(slow lifting of ring rail)

Ring Package (Cop)

Tube

Cross layer(fast descending)

Package buildingmotion

Db

Bobbin

Traveller

Ring

Dr

Ff

Fc

Fw Sin() = Ff2

2

Dr

VmFcFf

VSin() = (Db/2) / (Dr/2)

= Db / Dr

Fw = FfDr / Db

Db

VmFw

2

2 V = nDr

n

Fw

Db

nDrmFw

2)(2

Yarn tension increases with

Traveller weight m

Square of ring diameter Dr

Square of spindle speed n

Yarn tension decreases with

Bobbin diameter Db

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v= fBasic Wave Equation

Given string tension T, string density (mass/length)Wave velocity

Tv

STANDING WAVES ON A STRING

AntinodeNode

L = /2

STANDING WAVES ON A STRINGFundamental (First) Harmonic

/2 HH < /2

v= f

= v/f

Tv

tex

T

f

k

tex

T

n

KH

f= spindle speed n

= texFor spinning

tex

T

n

KH

T> H2 n2 tex / K

Square of spindle speed

Yarn tension increases with

Square of balloon height

Yarn linear density

Problem: Higher tension increased yarn breakage

Solutions?

Reduce balloon size

Limit spindle speed

Not a problem for thicker yarns

Reduce balloon size

Smaller D

Lower H

Smaller Package

Higher Cost of Doffing

Lower Efficiency

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H1

H2

Balloon Control

Tension Control: Traveller size

Minimum:Stable balloon atmaximum package diameter and balloon height

Db

nDrmFw

2)(

2

T> H2 n2 tex / K

m> kH2texDb/Dr2 k H2tex/Drkdepends on traveller/ring friction

No theoretical prediction, decided by trial:

Higher spinning tension better straightening &parallelizing thus higher yarn strength, lower extension

Increase in yarn strength may be more than increasein tension thus lower end-breakage rate

Better heat transfer

Smoother traveller running

Tighter package: easier to handle/longer yarn length

Heavier Traveller

With fixed spindle speed, increase delivery speed(decreasing twist) until break. Traveller with highestdelivery speed at break can be used initially

Higher power cost (traveller motion, winding tension)

Traveller No.(ISO) Guide

11210036

1009030

907124

715620

5645174535.514

4031.512

35.52610

31.523.69

28208

22.4167

146

12.55.5

95

Synthetics / BlendsCottonYarn Tex

(ISO No.=

g/1000 travellers)

ISO Traveller Number Guide

0

30

60

90

120

0 10 20 30 40

Yarn Tex

TravellerNo.

Cotton

Synthetics /Blends

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Traveller and Ring Design

Max. Contact Area (heat transfer& smooth running)

Low Centre of Gravity

Adequate Yarn Passage

Fibre / Yarn Requirement

Traveller and Ring Material

Low Heat Generation

High Heat Conductivity

High Wear Resistance (harder ring)

Steel + Surface Treatment (nickel, silver plating, chemical, etc)

Key Traveller Parameters

Traveller form (C, oval-flat, elliptical, N)flat wire

Low yarn hairiness, for fine cotton / viscose yarns

semi-round wire

For blends, cotton and synthetics. Goodresults with low twisted (knitting) yarn

ultra semi-round wire

For cotton, blends and synthetics. This wide profileoffers a large contact surface, for high speeds

flat round (combined profiles)For acrylics, special synthetics and core yarn.Flat toe, round yarn passage, for higher speed

flat round (combined profiles)For acrylics, special synthetics and core yarn.Flat toe, round yarn passage, for higher speed

semi-round highSpecial section, designed for SU travellers

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1. Spinning Power

Dependent on

Winding Tension

Yarn Rotation

Yarn Friction (traveller, yarn guide)

Traveller Motion

Yarn Tex

Balloon Height

Ring Diameter

Spindle Speed

Power consumption in ring spinning

2. Package Power

Dependent on:

Package Rotation(air resistance, bearing friction)

Spindle Speed

Package Size (ring diameter, balloon height)Higher balloon is more economical than larger ring

Power consumption in ring spinning

Primary Power =

Spinning Power + Package Power

Spindle Drive Efficiency (~40%) =

Primary Power 100Primary Power + Transmission Loss

Building mechanism and draftingsystem consumes about 10% of the

total power required

Ring Size

Doffing & Subsequent Handling

Piecing Frequency

Traveller (Spindle Speed)

Power Requirement

Capital Cost (Space & Machine)

Dependent on:

Count

Production rate

Utilisation factors

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Front roller speed (lapping, piecing) (coarse yarn)

Spindle Speed

Production

Power consumption

Optimum is higher than physical limit

Traveller speed(particularly for high strength cotton yarn)

Balloon tension (end-breakage rate)(particularly for soft yarn)

Yarn damage (synthetics)

MinimumCost

Labour

Power

Capital

Material/Auxiliary

Practical

SpindleSpeed

Unit Cost

Optimum Spindle Speed

Compact Spinning

Recent Developments

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The Future of Ring Spinning ?

Most Versatile

Best Yarn Quality

Lower Operator Skill Requirement

Well Understood Technology

Large Installation Base

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