long staple processing - p2 infohouse · le yarn manufacturing opening & blending - (wool,...

Introduction Long Staple Processing

James E. Pardue, Associate Professor School of Textiles, North Carolina State University

When discussing the various spun yarn formation systems, the first question that normally comes to mind is, why do we need all these different systems? Why can't one yarn system be utilized to make all spun yarns? The answer is dictated by the end product and the type or characteristics of the yarn needed. For many years we have associated the cotton system with cotton, the woolen and worsted systems with wool. This is not the case, however. Synthetic fibers are being consumed at an ever increasing rate on all yarn forming systems, so using cotton and wool to describe a yarn forming system is a misnomer today. I like to refer to the spun yarn systems as the short staple and long staple yarn fonning systems. The cotton system can be considered as a means of utilizing relatively short staple, fine fibers for the formation of a smooth, strong, lean or low bulk yarn. This is created by the many processes through which the fibers pass with the corresponding high draft levels which straightens the fiber to a higher degree. This causes the fibers to lie more parallel to the axis of the strand so the twist can bind a greater portion of the fiber length into the cylinder of yarn. NOTE: In theory, with the fiber parallel to the axis before twist is inserted, one-eighth of an inch of each fiber is not trapped by the twist. This means there are more fiber ends per unit length standing out from the surface of the yarn. this means that a decreased portion of the fiber strength is imparted to the yarn, which is why a spun yarn is weaker than a filament yarn of the same size. Most people connect the worsted system with the woolen system, but actually the worsted system takes over where the cotton system ends, as far as fiber length is concerned. We normally consider a fiber of 2.5 inch staple as maximum for the cotton system and as a minimum length for the worsted system. Then the worsted system is used to make the same type yarn as the cotton system, with fiber lengths ranging up to 9 inches. NOTE: With the longer staple length, there are fewer individual fibers per length of yarn; therefore, fewer fiber ends on the surface. Looking at this from another viewpoint, since the fiber length above three inches does not contribute substantially to the strength of the yarn, higher spindle speeds with a corresponding increase in centrihgal force will cause a greater fiber length to stand out from the surface of the yarn, creating a fuzzier yarn, and hence, more surface cover to the fabric. The Woolen system is entirely different from the other yarn forming systems in regard to the types of yarns produced. with a simplified flow system, fewer

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b

6-2 Long Staple Processing

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manufacturing processes, and low draft levels causing less fiber orientation, a bulkier yarn is produced. The fibers are not parallel when they reach the spinning process, but are crossed and intertwined. The fibers are trapped in this position with the insertion df twist, creating air pockets in the yarn, and more fiber ends standing out on the surface of the yarn. This increases the volume per unit weight. We can summarize by saying that the primary end use of yarns made on the cotton system are such things as knit undergarments and men’s hosiery, sheetings, broadcloth, summer suitings and other hard finish fabrics, as well as fine flannels, herringbone, etc. The woolen system makes yarns for such things as blankets, heavy suitings for men and women, including flannels, tweeds, herringbone, etc., and spun carpet yarn. Now, how do we process fibers into yarns on the woolen and worsted systems and control their characteristics?

Long Staple Processing 6-3

Woolen And Worsted Systems Worsted

Chemical Cleaning

Acid Treat* I ;: 1 I

Mechanical Cleaning

I Roller-Top Carding

Pin Drafting (X Times)

Combing I

I Pin Drafting (Y Times)

I Roving I

Ring Spinning I I Winding I

Woolen

E l

Chemical Cleaning scour

Acid Treat* Wash

Oil

Mechanical Cleaning v And Tape Condenser

I

I I Ringspinning

Winding Or Skeining

NOTE: Waste from the worsted process is often sold to woolen processors.

* Optional depending on vegetable matter content


A Typical Tow-To-Top System (Stretch- Break System)

Stretch F "p" Stretch I";"[

8 Top (Sliver)

Ring Spinning

(To provide potential bulk in product and to reduce the breaking elongation of the tow to facilitate stretch breaking).

(Rollers are massive and therefore only long staple can be produced in a single pass. Draw ratio greater than breaking elongation of tow feed). (To give cohesion to staple fibers).

I

Preliminary Treatments

Long

Preliminary Treatments

Stap

Opening & Blending

le Yarn Manufacturing

Opening & Blending

- (wool, man-made)

Picking - (optional) Picking

Carding (2 or 3 sections)

Roving

4l Spinning Spinning

Winding P A

Plying 9

MODIFIED WORSTED

Tow to Sliver

Fiber Settting

Carding

I I ServoDrafting

Combing (opt.)

Winding 9 Plying v

Winding r l

1 Servo Drafting T

Plying x Winding


Characteristics Of Woolen Yarns

Wool fibers usually less than two inches in length

Made from carded yams

Fuzzy; fiber ends protrude from yam

Uneven diameter

Bulky and thick

Wide range of fiber length

Spongy and springy feel

Result in soft, bouncy fabric structure

Hidden weave construction

Allow for napping and brushing finishes

Replace insulating properties providing warmth (used in outerwear type garments)

Resist wrinkling; wrinkles hang out

Do not hold a crease well

Fibers used can be from soft wastes or hard wastes

9 - Shrinking of wool goods after they are woven makes it possible to conceal many varieties of fibers.

Long Staple Procwslng 6-7

--

Figure 6-1 Feeding End Of A Continuous Scouring Train

SCOURING BOWL DE LIVERY SQUEEZE - - FEEDER 52ft. x 42in. LAlllCE ROLLERS I

O h FOR WASTE UQUOR


I

Table 6-1 Operational Data For Desuin ling Method

4 3 Bowl 1 2

24 16 32 16

1,000

Length, ft

2,000 1,000 1,500 Capacity

Initial charge, lb Soda ash Soap

75 10

10 7

Hourly Feed Soda ash Soap

5 3

25 -

3 2.5 1.5 1.5 Immersion Time, min.

90 130 120 Temperature, OF 125

--


I

1,000

10

5

750

1.5

Table 6-2 Operational Data For Neutral Scouring Process

1,000

- -

750

1.5

Bowl I I Length,ft

I Capacity, gal

I Initial charge, a lb detergent

I Hourly feed, Ib detergent

I. Flow back, gph

I Immersion time, min

I Temperature, OF

112 32 1 24

2,000 1,500 + - I 750

3 I 2.5

90 I 150

3 1 4

150 I 120

'r,

Initial charge and feed rate for fine domestic wool


Figure 6-2 Drying End Of A Continuous Scouring Train

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Long Staple Processing 6-1 1

Figure 6-3 Fearnaught Teaser Or Picker


Figure 6-4 Worsted Card

I GOSSETT MACHINE WORKS


Figure 6-5 Diagram Of Three-Cylinder Woolen Card

6-14 Long Staple Proceslng

Figure 6-6 Cross Lapper

Breaker cardset

--

To Finisher Card Set


Figure 6-7 Tape Condenser

Rubbings

F l w n card

W WebDivision


Figure 6-8 Sectional Elevation Of The Double-Sides MWR 5 Platt Ring Spinning

P

Long Staple Processing 6-1 7

I

Figure 6-9 HMG Chain Gill Drafting System


Figure 6- 10 Raper Autolever Pindrafter

------- I -

f .

3 '

-

I II m


3

Figure 6-1 1 Schlumberger Comb

_-


r t I

t Figure 6-12 Details of a French Comb

--

A. FeedRolls B. Feeding Gills C. Nipper Jaws D. Comb Cylinder E. Top or Intersector Comb

F. Drawing-off Rolls G. BrushRoller H. Noil Roller I. DofferComb

Long Staple Precessing 6-21

I

Figure 6- 13 Intersecting Pindrafter, Three-Roll Delivery

,

‘L !

! 6-22 Long Staple Processing

Figure 6- 14 Roving

_-


TR

Figure 6- 15 Ring Spinning

DRAFT ROLLERS

1' THREAD GUIDE

U RAIL

.E R

_-


ROVING

I

Figure 6-16 Open Wind Coner

Yam-Groove Traverse Cam-Acthrated Traverse

/


Take-L Driving

' Traverse Drum

I

Characteristics Of Worsted Yarns

Wool fibers usually 2 - 8 inches in length

0 Made from combed yams

Smooth

Even diameter

Tightly twisted

Fine, hard yarns

Distinct weave construction

-cI Do not produce insulating properties

Show undesirable wrinkles

Maintain desired crease

6-26 L ~ n g Staple processing

Figure 6- 17 Heat Stretch

4'g 0 0

Q I I


Figure 6- 18 Continuous Sliver Relaxer (CSR) Piping Arangement

Hkrh

k." I

inhlD 1 3 m )

ppe hrrkded


long staple processing - p2 infohouse · le yarn manufacturing opening & blending - (wool,...

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