North Carolina State University Omcc of Cootinlling Eduation and Rofariod Development
Dirkion of Univerdty Ertcadon
MEMORAHDUH TO: Short Course Participants
Tho Offico of Continuing Education C Profomsional Dovelopment (OCECPD) welcomes you to this North Carolina State University short course. We hope your e%periences here are pleasant and rewarding. If you have noeds while you aro h u e that aren't baing met, please let um know.
i would liko to call your attontion to on. important a8pect of your participation in thi8 cour80. You will be awarded Continuing Education Unit. (CEDs) for muccessful completion of this program. One CEU is awarded for uch 10 hour8 of iMtruction, with the undustanding that tho 8tudurtmut bo pro8ont for at least 908 of the instruction. The CW is a nationally recognized uniform unit of moamuramont providing the participant vith educational units which can be accumulated and u e d a8 evidence of profemsional development. In an incrusing number of irutances, CEWS are used for certification, licuming and am a factor in promotion.
The staff greatly appreciate. your comment. about the program you are attending. We also welcome suggestions for new courses to meet your educational needs, as we are continually goarching for subject areas not included in tho more than 600 conferences, workshops, short courses and seminars now being .offered.
Again, we are pleased to have the opportunity to sene you and hope you return often.
B. Marston, Director of Continuing Education Professional Development
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North Carolina State University College of Textiles
The North Carolina State University College of Textiles Serves the citizens of Nonh Carolina through .education. research and extension programs.
Founded in 1899, this institution with an enrollment of close to 1.OOO students, now dominates textile education in the United States. At the present time, nearly half of all textile university-based undergraduate degrees are awarded here. Fifty percent of all master’s candidates and 75 percent of all textile Ph.D.’s are currently enrolled in the college.
Reflecting the diversity of the industry itself. the curriculum includes Bachelor of Science degrees in texules, textile and apparel managemenL textile science, textile engineering and textile chemistry. Within some of these degree programs, a student may specialize in textile design. textile technology. textile management, apparel management, polymer chemistry. dyeing and finishing science, dyeing and finishing technology, and dyeing and finishing management
The textiles degree program is designed to provide a broad foundarion in textile technology. beginning with the basic raw material and progressing through to the finished fabric. Students enrolled in this curriculum may sptcialize further in the areas of textile design or advanced textile technology. Textiles program graduates typically fill design and manufacturing management positions in fiber and texule manufacturing fms.
Students enrolled in the textile and apparel management program will obtain a solid background in texules, in addition to management concepts and applications. Specializations in textile management or apparel management arc possible. Graduates of hese programs are in demand to fill positions in production, tezhnical services, sales, markuing.
- purchasing, personnel and other related management and staff functions.
--
Another program offering outstanding opportunities for students is the textile science program. which emphasizes research, development, and applications of advanced technology to the fiber and textile industries. It is also a good choice for
students interested in pursuing advanced degrees in scientific and technical disciplines.
Students studying textile chemistry can concentrate on dyeing and fmishing science, polymer ‘science, dyeing and finishing operations. and dyeing and finishing management. These students are in great demand in the numerous textde operations that emphasize dyeing and fmishing. many of which are located in North Carolina. or in polymer-related research and development activities throughout the fiber and textile indusmes.
Students studying textile engineering leam how to apply scientific principles and engineering prar;tices to the widely diversified aspects of texule processes. products and machinery. This degree program is operawf jointly with the College of Engineering.
The NCSU College of Textiles offers muate programs leading to the Master of Science. Master of Textiles. and Doctor of Philosophy degrees. Graduates with advanced textile degrees are constantly in short supply and great demand.
The curriculum of the college is v e d e and comprehensive, providing instruction both on and off campus. Extension programs provide numerous short courses, conferences and workshops on a grtat variety of subjects of interest to the fiber, textile and apparel industries. In addition to these programs, Textiles Extension also offers a wide variety of in-plant courses.
Credit courses via the Textile Off-Campus Televised Education (TOTE) Program are offered internationally. Enrollment averages approximately 160 students pcr academic year. Courses are offered at the undergraduate and graduate levels. Students can eam a Master of Textiles with a specialization in Textile and Apparel Management and Technology: Textile Engineering and Science: and Textile Chemistry. TOTE classes an available to any individual seeking an improved textdes education or background. In addition a visual aid rental seMce is available u) the industry.
WEFT KNITTING FUNDAMENTALS
BUS SCHEDULE
AUGUST 22 - 25,1994
Monday, August 22
7:45am 4:OOpm 6:30pm Embassy Suites to Simpson’s 9:OOpm Simpson’s to Embassy Suites
Embassy Suites to College of Textiles College of Textiles to Embassy Suites
Tuesday, August 23
8:OOam 4:OOpm
Embassy Suites to College of Textiles College of Textiles to Embassy Suites
Wednesday, August 24
8:OOam 4:OOpm
Embassy Suites to College of Textiles College of Textiles to Embassy Suites
Thursday, August 25
8:OOam 12:OO noon
Embassy Suites to College of Textiles College of Textiles to Embassy Suites
WEFT KNITTING FUNDAMENTALS Gary W. Smith
1. Knitting Yarns: A. Yarn Classifications:
a. Spun:
Singles vs. Plied
Spun Yam Classifications And Comparisons Ring Open-End Carded Combed
strength
cost
uniformity
twist
cover
count range
b. Filament: Flat vs. Textured
Influence of Filament Count and Stretch
1
c. Elastomeric: Elastomeric Yam Comparisons
Bare Single Covered Double Covered
cost
extensibility
stability
B. Implications of New Yam Developments: a. package sizehhape
. b. uniformity
c. friction
d. joining techniques
C. Yarn Requirements: a. strength
b. count variation
c. uniformity
d. twist
e. friction
f. elongation
g. colorhhade
h. packaging
2
D. Yam Numbering Systems: a. Indirect:
Cotton Count: number of 840 yard lengths per pound Comparisons of Yam Counts 20/1 30/1 3012
cost
thickness
uniformity
b. Direct:
Denier: weight in grams of 9000 meters of yam Decitex: weight in grams of 10000 meters of yam
Comparisons of Yam Deniers 1/70/13 l/70/34 2/70/34
cost
thickness
Uniformity
Count Importances:
2. Weft Knitting: A. Classifications:
a. Structure aa. Jersey bb. Rib
-- cc. Purl
3
Knitting
4
_-
Weft Knitting Machine
5
Weft Knitting
---
N e e c h k ]&E% h 4 I1 I 1 1
6
b. Machine aa. Single Cylinder
cc. V-Bed
c. Format aa. Tubular
d. Diameter aa. Small
bb. Dial and Cylinder
3- dd. Purl
bb. Flat
bb. Large
B. Definitions: a. Course: - a horizontal row of loops W
Feeder: - an actual course Visual: - a visual course CPI:
b.
C.
e.
Wale: - a vertical column of loops
WPI:
Knit loop: Tuck loop: Float loop:
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Technical Face
Single Jersey
Technical Back
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f. Feeder: - a unit which guides a yam to the needles
g. Needle: - an element which forms loops and wales ';1 h. Sinker: - an element on jersey machines which assists needles
hold fabric during knitting
i. Tricks: - slots which guide needles during knitting
j. Cylinder: - a cylinder drum which contains slots, needles and (sometimes) sinkers
k. Dial: - a horizontal plate which contains slots and horizontal needles
1. Loop Length: - the average amount of yam in a loop
m.Course length: - the amount of yam required to knit one complete course cnruuy
Run-In: Ravel length: Draw:
n. GuageKut: - normally the number of needles per inch
u IIIIIIIIIIII 0. Gaiting: - the arrangement of two sets of needles
Rib Gaiting: cr/ 7 7
Interlock Gaiting:
7 7 p. Timing: - relative movement between two sets of needles or
~ needles and sinkers --
q. Negative Feed: - yam pulled from the yam package by the action of the needles
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r. Positive Feed: - yarn metered to the needles at a preset rate s. Yield: - the weight per unit of fabric
Oz/yd2:
Oflinear yard:
Yarddpound:
Conversions:
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I ~
~
i
C. Knitted Fabric Properties: a. Stretch and Recover:
b. Shrinkage:
c. Crease Resistance:
d. Spirality:
e. Snagging:
f. Pilling:
g. Bulk:
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D. Notation: a. Verbal:
b. Graphic:
c. Symbolic:
Knit Tuck Face Rear Face Rear B E I E l m
Examples:
d. Diagrammatic:
mit(Face) G Tuck(Face) \d Float (Face) Y
Interlock Gaiting 0 m c '
Float Face Rear 17 0
Knit (Rear) 2 L
Tuck(Rear) A Floatwear) A
RibGaiting o , . - c
Examples:
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E. Loop Classifications And Fabric Modifications: Knit KnitfI'uck
length Knit/Float
width
thickness
cost
extensibility
effect
weight
knitability
CPI
F. Introduction to Machine Functions And Considerations: a. Creel:
b. Knitting Zone:
c. Fabric Take-up And Collection:
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3. Jersey Knitting: A. Jersey Knitting Cycles:
a. Plain Jersey:
b. Tuck Jersey:
c. Float Jersey:
B. Camming Systems, Raceway Units And Notation:
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Needle Cylinder
n
16
Ty p i ca I Cam System of Single Jersy Machine
Direction Of Needle Travel * I NeedleMotionReuuired I
Cleating
m
Running
Knockover
F I
Loop Pulling
L
17
b I
18
Latch Needle Activation
i
3 + e
3
19
Movements of Latch Needles and Web Holding Sinkers
a A
D
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A
Knit Loop
B
Tuck Loop Formation Tuck Loop
21
A
Float Loop
22
Tuck Stitch Formation
Y Y 4
A @! Y
6 4
P
23
Float Stitch Formation
Float Stitch Formation
24
C. Factors Influencing Knitability And Productivity: a. yam characteristics:
b. yam specifications:
c. yam purchasing and storage:
d. machine character and tensions:
e. fabric structure and tightness:
f. ambient conditions:
g. cleanliness:
h. preventative maintenance:
i. inventory policies:
-- 1 j. operator/technician load:
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k. training:
1. detector usage and monitoring:
D. Single Knit Fabric Classifications: Plain Jersey Striped Jersey Flat Jacquard TerryNelour Plaited Jersey
. E. Specific Jersey Fabric Characteristics: a. Plain Jersey:
b. Striped Jersey:
c. Tuck Jersey:
Tuck Jersey Fleece
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Knit Loop
Tuck Loop Float Loop
27
Laying-In Weft Knit Fabric
28
d. Flat Jacquard
e. TerryNelour:
f. Fleece:
g. Plaited Jersey
F. Jersey Fabric Modifications:
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G. Starfish Concepts: a. Yam Control:
b. Course Length Control:
c. Tension Control:
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4. Rib Knitting: A. Rib Knitting Cycles:
a. Dial and Cylinder Machines: b. V-Bed Machines:
B. Gaiting Considerations:
C. Needle Timing Considerations:
D. Rib Fabric Classifications: a. Simple Ribs:
1x1 2x2 2x1 3x3 6x3 Half' Cardigan Full Cardigan Thermal
b. Complex Ribs: aa. Plain Interlock
bb. Relief Cords
Ponte de Roma
Blisters
cc. Flat Jacquard -- - 2 Color 3 Color
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Cylinder and Dial
w- Tricks
d
32
Rib Gaiting
33
I
Feeder 2 (Short Needles) m
34
Rib Camming
Dial Needle
I - / swingcam Guard Cam
Clearin Cam (Tuck dight)
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Dial Cam Section
Numbers 1 and 2 show the location of cams which change needles from inoperative position to tuck position. Numbers 3 and 4 show the location of swing cams which work along with the tuck cam to take needles up to knitting position. Numbers 5 and 6 show the location of adjustable stitch cams controlling the size of loops.
L SwingCam3 SwingCam
/ /- ShortNeedle / / I (In Action)
Tuckcams’ 7 a Long Needle Tuck Cams 2 (Out Of Action)
5And6
short . Needle Swing Cam (In Action)
LongNeedle Swin Cam4 (Out 8 f Action)
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Timing
CYL TRICKS
DELAYED TIMING
SYNCHRONIZED TIMING
I . CLEAR Cast
ADVANCED TIMING
Ll \ADVANCED
- -- Dasned line depicis cylinder needle path- Solid line depiz:s dial needies path
37
'V' Bed Rib
38
1 x 1 Rib
39
40
E. Rib Fabric Characteristics: a. Simple Ribs:
1x1
2x2
2x1
Half Cardigan
Full Cardigan
3x3
41
Thermal
Modified
F. ComplexRibs: a. Plain:
Interlock
Single Pique’
42
Ponte-de-Roma
Swiss Double Pique’
Milano Rib
b. Relief Cords
43
Blisters
c. Flat Jacquards: 2 Color
3 Color
5. Fabric Packaging And Handling Considerations:
44
t
6. Purl Fabrics:
A. Fabric Classifications: a. Plain b. Fancy
B. Knitting Action:
7. Hosiery: A. Indentification And Knitting Sequences:
B. Machinery Classifications And Overviews: a. Rotary b. Reciprocating
c. Mechanical
-- ~ e. Jersey
d. Electronic
f Ribfir1
45
1 x 1 Purl
Face
Back
course
course
46
C
1
Stitching
f - --- i 5- I- #Plain
2
I
B 3
47
4 (Rib) --
I
Half-Hoser
48
C. Machinery Vs. Product Classifications:
D. Shaping:
E. Pattern Capabilities:
F. Trends:
G. Special Considerations In Hosiery:
49
8. Machinery Developments And Purchasing Considerations:
A. Developments:
B. Considerations:
a. Cost
b. Reputation
c. TrialResults
d. Automation and Patterning
e. Warrantees, Maintenance and Service
f Productivity and Quality
g. Creel Design
~ -- h. Diameter
50
I
i. Gauge
j. Feeds
k. Spreader
1. Training
m. Inventory
n. Set-up and Plant Requirements
0. Cleaning System
p. Lubrication
q. Monitoring System
r. Feeding System .-
s. Capacity And Doffing System
51
9. Production Calculations:
C. Productivity
53
I
Reading 1
Reading 2
Reading 3
Reading 4
Reading 5
X
Name:
SamDle Tech Face Tech Rear
Date: Style:
Reading 5
LOOP Length
Weft Knit Analysis Yarn Type: Yarn Count:
------
Courses Per Inch Wales Per Inch
Loop Length And Run-In Feeder Number
1 2 3 4 5 6
Diameter: cut: Total Needles: Calculated Run-In:
54
11. Knit Fabric Defects
A. Barr6 - Horizontal bands following courses around the tube.
Yam count variations (count uniformity)
Twist yam tension variations
Wrong yam - size, color, blend level, twist direction
Uneven oiling or waxing of yam
Malfunctioning of storage or tape feeders
Crooked dial needle bed
Different stitch settings
Faulty cylinder or dial cam settings
Dirt, lint, yam fragments in the cam system, tricks, needles or sinkers
Improper threading of yarn
Faulty take down-spreader system
Machine vibration
55
B. Vertical Lines - Following the wales up the length of the tube - usually mechanical.
Broken needles
Bent needles - stem, hook - sinkers
Dirty needles
Bent or stiff latches
Closed latches
Worn tricks - needles, sinkers
Dirty tricks - needles, sinkers
Dial and cylinder needle misalignment (timing, gaiting problems) - needles rub
Improper setting of yam guides
Machine vibration
Spreader abrasiodcreasing
Improperly set spacers on take-up
Folds from too narrow spreading at take-up
Oil lines
Wrong needle
Mixed needle lots
56
C. Holes - Yarn or mechanical in nature.
High friction - between yam and guides
Insufficient wax or oil
Poor quality (strength, elongation)
Too much yam tension
Knots
Improper yam size for gauge
Snarling of yam (twist lively)
Slubs, trash
Lint (low twist, extreme hairiness, poor cleanliness)
Low humidity
static
Improper setting of yam guides
Feeder problems (tight, rough places)
Faulty height adjustment of sinkers
Baa! c!6417;fl3
57
D. Stitch Runs - Random Or Continuous.
Yam tension too high (check yam path)
Yam snagging
Yam snarling - knots
Too high machine starting speed
Low yam tensions during running
Incorrect feeding of the yam
Inaccurate setting of distance between dial and cylinder
Improper take-down tension
Defective needle
Defective sinker
Machine vibration
58
I
E. Dropped Stitches
Improper setting of yam camer
Obstructed yam carrier
Improper needle timing between dial and cylinder
Twist liveliness of yarn
Bad needle (bent latch, hook)
Too tight of stitch (run-in or cam setting)
High yam tension
Too high of a dial height
Too high take-down tension
59