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:

7

Technical Face

Single Jersey

Technical Back

8

9

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:

11

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:

15

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

20

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:

29

G. Starfish Concepts: a. Yam Control:

b. Course Length Control:

c. Tension Control:

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I

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

31

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)

35

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)

36

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