Document 101612

Iyer / Mammel / Schach
Circular Knitting
Technology Process
Structures Yarns
Quality
603U
FRANK
by Meisenbach Bamberg
Contents
01
Knitting Technique . . . 1
01.1
Fundamentals of stitch formation . . . 1
01.1.1
4 0 0 years of mechanical stitch formation
01.1.2
An outline of knitting machines
01.1.3
Stitch formation w i t h latch needles . . . 9
01.1.4
Structural elements in knitted fabrics ... 10
01.1.4.1 Loop ... 10
01.1.4.2 Stitch ... 10 / Plain stitch / Purl stitch /
Needle loop / Sinker-loop-.-- ..'
:
01.1.4.3 Tuck loop ... 10 •
'
.
01.1.4.4 Float stitch ... 10 : ,
01.1.4.5 Weft ... 10
{
01.1.4.6
Filler ... 10
u
- " -•-•
... 1
... 6
- • '•
....
01.1.5
Basic knitted structures ... 12
01.1.5.1 Arrangement of structural elements ... 12
01.1.5.2 Plain knitted fabrics ... 12
01.1.5.3 Double knit fabrics (rechts/rechts fabrics) ... 12
Double knit rib fabrics /
Double knit interlock fabrics
01.1.5.4 Double knit purl fabrics ... 12
01.2
Processes for large circular knitting machines . . . 14
01.2.1
Plain (rechts/links) technique with latch needles ... 14
01.2.1.1 Rest or ground position, Pos. 1 ... 16
01.2.1.2 Tucking-in position, Pos. 2 ... 16
01.2.1.3 Clearing position, Pos. 3 ... 16
01.2.1.4 Yarn presenting position, Pos. 4 ... 16
01.2.1.5 Cast-on position, Pos. 5 ... 17
01.2.1.6 Knock-over position, Pos. 6 ... 17
01.2.2
Relative technology with latch needles ... 18
01.2.3
Compound needle technique ... 20
01.2.3.1 Plain technique with compound needles ... 20
01.2.3.2 Plain relative technique with compound needles ... 24
01.2.4
Rib technique ... 27
01.2.4.1 Coordination between cylinder and dial grooves ... 27
Rib setting of cylinder and dial / Interlock setting of cylinder
and dial / Conversion from rib to interlock setting
"01.2.4.2 Coordination, between cylinder and dial cams ... 29
Synchronised timing between cylinder and dial cams /
Delayed timing between cylinder and dial cams / Conditions
for the use of delayed timing for dial and cylinder cams
01.2.5
Purl technique ... 38
01.2.5.1 Rib stitch formation ... 38
01.2.5.2 Purl stitch formation and needle transfer ... 38
Contents
V
01.3
01.3.1
Characteristics of circular knitting machines ... 44
Machine pitch and machine gauge ... 4 4
0 1 . 3 . 1 . 1 Machine pitch ... 44
0 1 . 3 . 1 . 2 English machine gauge ... 4 4
0 1 . 3 . 1 . 3 Pitch values for circular knitting machines
with special pattern devices and for small circular knitting
machines ... 44
0 1 . 3 . 1 . 4 Relation between machine pitch, English gauge,
machine nominal diameter and number of needles ... 44
0 1 . 3 . 1 . 5 Effective machine pitches (machine gauges) ... 4 4
01 .3.2
01 .3.3
Machine nominal diameter ... 45
01 .3.4
01 .3.5
Production speed, number of machine revolutions ... 45
01 .4
01 .4.1
Machine elements ... 46
01 .4.2
Number of feeders / feeder density ... 45
Efficiency value / speed factor ... 46
Frame ... 46
Machine drive ... 48
01.4.2.1
01.4.2.2
01.4.2.3
01.4.2.4
01.4.3
Motor ... 48
Number of revolutions of the machine . . . 4 9
Brake ... 51
Drive arrangement ... 52
Knitting elements ... 52
0 1 . 4 . 3 . 1 Needles ... 53
0 1 . 4 . 3 . 2 Holding-down / Knocking-over sinkers ... 58
0 1 . 4 . 3 . 3 Needle beds on circular knitting machines ... 60
01.4.4
01.4.5
Yarn feeder and its correct setting ... 61
Needle and sinker control units (cams) ... 63
01.4.5.1
01.4.5.2
01.4.5.3
01.4.5.4
01.4.6
Fabric take-down ... 72
01.4.6.1 Fabric spreader ... 72
01.4.6.2 Fabric tensioning and winding devices ... 72
Fabric tensioning and winding devices with mechanical drive /
Fabric tensioning and winding devices with- electrical drive
01.4.7
Yarn supply ... 79
01.4.7.1 Cone carrier device ... 79
01.4.7.2 Yarn delivery devices (Yarn metering and storage devices
on circular knitting machines) ... 84
Yarn delivery devices for constant yarn delivery, yarn metering
devices / Devices with constant yarn delivery per unit time,
Yarn metering devices with yarn reserve (Positive yarn
feeders) / Devices with variable yarn delivery per unit time and
yarn reserve (Storage yarn feeders)
01.4.8
Monitoring and maintenance systems ... 94 /
,
VI
Contents
Sliding cams ... 65
Flexible cams ... 66
Changeable cams ... 67
Alteration of course density through couliering ... 68
Vertical couliering / Diagonal couliering / Central couliering /
Vertical adjustment of needle dial
Yarn monitoring / Needle monitoring / Fabric monitoring /
Lubricating and oiling systems / Cleaning systems
Needle Control and its Equipment . . . 9 7
02.1
Direct needle control ... 97
02.1.1
02.1.2
Control through cam parts ... 97
Control through pattern wheel ... 98
02.2
02.2.1
Indirect needle control ... 101
Indirect needle control with fixed control sinker
arrangement ... 101
02.2.2
Indirect needle control through pattern drum ... 103
02.3
Electronically controlled needle selection
on circular knitting machines ... 106
02.3.1
Needle control through film tape ... 106
02.3.2
02.3.3
Needle control through machine memory ... 108
Pattern design and production preparation ... 111
03
Additional Equipment Patterning . . . 113
03.1
Equipment for fleecy fabrics ... 113
03.1.1
03.1.2
Simple fleecy ... 113
Three-thread fleecy ... 113
03.2
Equipment for plush fabrics ... 118
Quality demands on plush
03.2.1
Unpatterned plush ... 118
03.2.2
Jacquard plush ... 122
The construction of the presentation technique
03.3
Yarn changer devices / stripers ... 126
03.3.1
Yarn changer device with mechanical control ... 126
03.3.2
Yarn changer device with electronical control ... 128
03.4
Wrap finger technique ... 132
Circular Knitting Machines
for Garment Length Fabrics . . . 135
04.1
Rib and purl techniques ... 136
04.1.1
Fibres and yarns ... 136
04.1.2
04.1.3
Stitch density and quality ... 136
Performance ... 136
04.2
04.2.1
Purl pullover circular knitting machine ... 137
Double selection at the lower cylinder ... 137
04.2.2
Selection at the upper cylinde'r ... 138
04.3
Rib pullover.circular knitting machine ... 140
04.3.1
Free individual needle selection in the knitting feeders ... 141
04.3.2
Means of free selection in the transfer feeders ... 141
04.3.3
Principle of selection ... 142
Contents V I I
05
Machine for High-Pile Fabrics . . . 144
06
Other Machines . . . 146
06.1
Methods for loop transfer ... 146
06.1.1
Transferring of sinker loops ... 146
06.1.2
Transferring of needle loops ... 146
06.2
Machines for the production of transfer patterns ... 147
Cylinder transfer feeder, control sinker cam range /
Cylinder transfer feeder, needle cam range . . . 150
Knitted and Fabric Structures . . . 1 5 2
07.1
Pattern analysis of weft knits ... 152
07.1.1
07.1.2
Tools and technical aids ... 152
Methodical pattern analysis ... 152
07.1.3
Representation of weft knitted fabrics ... 154
07.1.3.1
07.1.3.2
07.1.3.3
07.1.3.4
Representation through mesh structure . . . 154
Representation through technical notation (yarn path) . . . 154
Symbols used for representation of needles . . . 154
Representation of structural elements . . . 155
07.2
Basic structures ... 156
07.3
Patterned structures ... 156
07.3.1
Patterned structures with one needle type ... 156
07.3.2
Patterned structures with two needle types ... 157
Plain structures / Rib patterned structures /
Rib patterned interlock structures
07.3.3
Patterned structures with four needle types . . . 161
07.4
Plated structures ... 162
07.5
Speciality structures ... 162
Fleecy/Three-thread fleecy / Interlock fleecy / Plush
07.6
Jacquard structures ... 163
07.6.1
Colour jacquard structures . . . 163
Single jersey colour jacquard / Single jersey colour jacquard with
t
binding-in of floating yarns (three-way technique) / Rib colour jacquard /
Horizontal striper backing / Vertical striper backing / Twill backing
07.6.2
Rib relief jacquard structures . . . 166
Single relief rib jacquards / Double relief rib jacquard
VIII
Contens
07.6.3
07.6.4
07.6.5
Rib tuck jacquard ... 170
Rib lock jacquard ... 170
Rib transfer jacquard ... 170
07.7
Symbolic adjointment
between structure and process . . . 171
Plain circular knitting machines ... 172
Rib circular knitting machines . . . 178
07.8
Transposition of jacquard patterns
onto a jacquard circular knitting machine
with mechanical indirect needle control . . . 182
0 8
Yarns for Circular Knitting . . . 188
08.1
Fibre materials . . . 188
08.2
Count . . . 190
08.2.1
Direct system and its units... 190
08.2.2
Indirect system and its units ...191
Metric number (Nm) / English number (Ne)
08.2.3
Count calculation and denotion for plies . . . 191
08.2.3.1 Ply with yarns of the same count ... 194
Calculation of count on the direct system / Denotion based
on the direct system / Calculation of count on the indirect
system / Denotion based on the indirect system
08.2.3.2 Ply with yarns of differing counts ... 194
Calculation of count on the direct system / Denotion based on
the direct system / Calculation of count based on the indirect
system / Denotion based on the indirect system
08.3
Staple fibre yarns . . . 195
08.3.1
Spinning systems . . . 195
08.3.1.1 Cotton spinning system . . . 196
Carded yarn / Combed yarn
08.3.1.2 Worsted spinning system . . . 197
08.3.1.3 Semi-worsted spinning system . . . 197
08.3.1.4 Woollen spinning system ... 198
08.3.2
Spinning techniques for staple fibre yarns . . . 198
08.3.2.1 Ring spinning ... 198
08.3.2.2 Unconventional spinning techniques ... 199
OE rotor spinning / Other spinning techniques: Friction
spinning / Air jet spinning / Cover spinning / Yarns with ply
resemblance / Self-twist spinning / Ply spinning
08.3.3
Comparison between ring and rotor yarns ...- 201
08.3.3.1 Process-based properties ... 202
08.3.3.2 Fibre-based properties ... 202
08.4
Filament yarns . . . 203
08.4.1
The most importaQt raw materials . . . 203
08.4.2
Filament yarn types . . . 203
08.4.2.1 Monofilament yarn ... 203
08.4.2.2 Multifilament yarns ... 203
08.4.2.3 Minifil yarns ... 203
08.4.2.4 Comingled yarn ... 204
08.4.2.5 Microfilament yarn ... 204
Contents
IX
08.4.3
Flat and textured filament yarns ... 204
08.4.3.1
08.4.3.2
08.4.3.3
08.4.3.4
False twist process ... 204
Bicomponent process ... 206
Knit-de-knit process ... 206
Air texturing process ... 207
Single yarn / Parallel yarn / Core-sheath yarn
08.4.3.5 Other texturing processes ... 208
08.4.3.6 Properties of textured yams ... 208
Primary properties: Extension and elasticity / Volume /
Secondary properties: Weight / Dyeing behaviour /
Handle / Perspiration / Air textured yam
08.5
Fibre blending in yarns and fabrics ... 209
08.5.1
Types of blend . . . 210
08.5.1.1 Intimate blending ... 210
08.5.1.2 Core-sheath structures ... 210
Covering / Bicomponent yarns/
Air textured yarns / Open end yarns
08.5.1.3 The real ply ... 211
08.5.1.4 Comingled yarns ... 211
08.5.1.5 Feeder blending ... 211
08.6
Yarn count and machine gauge ... 212
08.7
08.7.1
Knitting demands on yarns ... 216
Tenacity and breaking extension ... 216
08.7.2
08.7.3
Elasticity ... 218
Friction ... 218
08.7.3.1 Waxing of staple fibre yarns ... 219
08.7.3.2 Finishing of filament yarns ... 220
08.7.3.3 Surface of yarn and abradant ... 220
08.7.4
Yarn evenness ... 221
08.7.5
Yarn count deviation ... 222
08.7.6
Take-off behaviour of yarns ... 223
08.8
Yarn supply for circular knitting machines ... 224
08.8.1
08.8.2
Draw twist bobbin ... 224
Draw winder bobbin ... 224
08.8.3
Cross-wound bobbin ... 224
08.8.3.1 Package size ... 225
08.8.3.2 Package shape ... 225
Cylindrical shape / Biconical shape / Conical shape
08.8.4
Winding methods for cross-wound bobbins ... 226
08.8.4.1 Random winding ... 226
08.8.4.2 Precision winding ... 226
08.8.4.3 Digital winding ... 227
08.8.5
08.8.6
08.8.7
08.8.8
Wind-on speed ... 227 "
Package hardness ... 228
Tak.e-off yarn tension ... 228
Friction between yarn and cross-wound package ... 229
08.8.9
Negative yarn withdrawal ... 229
08.8.10 Positive yarn withdrawal ... 229
Contents
08.9
Literature to chapter 08 ... 230
09
Quality and Production Monitoring . . . 2 3 1
09.1
Faults and its causes in circular knitting . . . 231
09.1.1
Pre-requisites for faultless knitwear production . . . 231
09.1.1.1 Pre-requisites on the circular knitting machine ... 231
09.1.1.,2 General production conditions for knitting ... 232
'• Selection of proper yarn count / Relation between knitted
structures and processing problems / Setting of the
knitting machine / Yarn storage / Air conditioning
of the knitting plant / Cleaning of knitting machines
09.1.1.3 Yarn pre-requisites ... 234
Influence of dyeing processes / Influence of spinning
processes / Influence of the winding process /
Factors affecting yarn production / Relationship between
yarn properties and knitted fabric qualities
09.1.2
Frequent faults in knitted fabrics, their definition,
cause and elimination... 237
09.1.2.1 Definition of faults ... 237
09.1.2.2 Causes of faults and their avoidance ... 238
Cracks or holes / Drop stitches / Cloth fall-out / Snags /
Tuck and double stitches / Bunching-up / Vertical stripes /
Horizontal stripes / Soil stripes / Colour fly / Distorted stitches
09.1.3
Literature . . . 248
09.2
Operational data acquisition . . . 248
09.3
Production calculations . . . 250
10
Appendage for Tables . . . 353
10.1
Machine pitch and machine gauge . . . 252
10.2
Nominal machine diameters . . . 254
10.3
Number of feeders . . . 2 5 6
10.4
Yarn counts . . . 258
Fluff Blower Devices . . . 363
12
Index . . . 365
Contents
XI