03a knit structure

An introductionAn introduction

to knitted fabricsto knitted fabrics

Ing. Irena Lenfeldová, Ph.D. KTT, FT, TUL, 2008/2009

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History

The earliest known knitted fabric was a pair of socks found in an Egyptian tomb, which dates back to the 4th century B.C. Today, it is known that these early socks were worked in Nalebinding.

Nalebinding is an ancient craft which involves creating fabric from thread by making multiple knots or loops, and is done with a needle made of wood or bone.

• The first knitting machine was constructed around 1589 by an English reverend named William Lee (1550-1610).

• to knit an entire row of loops at once.

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In 1759, Jedediah Strutt of Derby and Belper patented the "Derby rib frame." This would have been the first conversion from a single bed to a double bed frame and started agreat period of inspiration for development for the knitting frames.

Crain & Porter came up with our first "color changer." I love the story of how strings were attached to needles and "drawboys" (yes, real boys) were instructed to draw back manually selected needles by means of these strings to create the twocolor work! From there the punch card system of selecting patterns was developed in 1798 by Joseph Marie Jacquard. At first, due to the popularity of lace, this accessory was used for lace fabric then developed into the multi color work.

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WILLIAM COTTON was born in SEAGRAVE in 1819. He became an apprentice to a firm of hand stocking machine builders(1846 – 1864 patented cotton machines). A common contemporary expression said that COTTON had "turned the needlesupside down."

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• Mr. Lamb of Northville invented the first domestic machine around 1867. It was said to have 84 needles and weigh about 15 lbs.

• The Reference in Cassell's Household Guide of 1870 advertised the Craine Knitter: "It had a massive metal plate keyboard in which deep, square grooves for the reception of 106 needles are cut, and "asort" of metal carriage or traveler, which can be moved forward or back on the keyboard with the greatest facility by the aid of a short ball-crowned handle." This was one of several sock knitting machines of that era.

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• Warp knitting , the second and smaller section of machine knitting, was never a handmanipulated craft. It was first developed by Crane and Porter in 1769 as a method of embroidery plating, by means of multiple warp thread guides, onto stocking fabric as itwas being knitted on the hand frame.

• As the technique improved, purely warp intermeshed loop structures without the weft knitted ground began to be knitted and Crane patented his warp loom in 1775. Tarrat is credited with developing the first efficient treadle-operated warp knitting frame in 1785.

• The German warp knitting industry developed in Chemnitz andApolda, afterReichel brought a British hand warp loom to Berlin in 1795.

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Basic terms

• Knitted fabric – are built up from row after row of intermeshed loops. The newly-fed yarn is converted into a new loop in each needle hook.

• Weft knitted fabric – can be unroved from the end of the fabric knitted last.

• Warp knitted fabric – threads tend to have an vertical path through the structure.

Loop – characteristic unit in knitted structure;

opened or closed

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Weft and warp knitted structure

The subsequent loops formed from one thread are placed in the same course.

The subsequent loops formed from one thread are placed in

the subsequent courses.

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Basic expressions• Stitch (loop) – can be intermeshed through the head of the

old loop in a manner that will show a face loop stitch on one side and a reverse loop stitch on the other side.

• Face loop– show the side limbs of the needle loops or overlaps as a series of interfitting ‘V’s. The face loop-side is the underside of the stitch on the needle.

• Reverse loop– shows the new loop meshing away from the viewer, show the sinker loops in weft knitting.

• Tuck stitch – the yarn passes from the sinker loops to the head that is intermeshed with the new loop of a course above it.

• Float stitch – shows the missed yarn floating on the reverse side of the held loop.

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Loops (stiches)

Needle head

Two limbs (legs)

Intermeshing point

Two foot

Old loop

Reverse loop Face loop

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Tuck and float stitch

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Basic conceptionsKnitted loops are arranged in rows, these are termed courses

and wales.• Coarse– is a horizontal row of needle loops produced by

adjacent needles during the same knitting cycle.• Wale – is a vertical column of intermeshed needle loops

generally produced by the same needle knitting at successive knitting cycles.

Basic parameters of knitted fabrics• Wale density [m-1] - is obtained by counting the number

of wales in one meter• Coarse density[m-1] - is obtained by counting the number

of coarses in one meter• Stitch density (square) [m-2] - refers to the total number

of loops in a measured area of fabric – e.g. 1 m2

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GAUGE: basic characteristic of the knitted machines.

• are normally gauged on the English system (E) of needles per inch (npi).

•one inch = 25,4 mm

It corresponds with the fine of machine and it influences choice of yarn count (linear density) which we want to used for producing the knitted fabrics. It affects fabric properties appearance and weight.

• Coarse gauge – 5

• Fine gauge - 40

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Types of structures

• Weft knitted structuresSingle-faced (plain): show the face stitches in the form of the

limbs of the loops as a series of interfitting „V“s.Double-faced (rib): show the face loops of one set on one side

and the face loops of the other set on the opposite side. Purl : face and reverse stitches in the same wale. Interlock : requires a special arrangement of needles knitting

back-to-back in an alternate sequence of two sets.• Warp knitted structuresSingle-facedDouble-faced

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Kniting notationsSymbolic representation of a knitting repeat sequence and eliminates the need of time-consuming written descriptions.

Three types of notation system:

System – prof. PRUSA: using the horizontal and vertical lines for each weft knitted structure.

System VUP: using the letter - symbol for each weft knitted element.

System: each point represents a needle in plan view from above and after the thread path has been drawn, it also represents itsweft stitch.

For warp knitting – lapping diagrams with the use of point paper.

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Prof.PRUSA

Face stitch Reverse stitch

Tuck stitch Float stitch

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VUP

_Float stitch

.Tuck stitch

OReverse stitch

VFace stitch

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System

Face loops

Reverse loops

Tuck stitches

Float stitch

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Some properties of knitted fabrics

• Extensibility

• Elasticity

• Drapeability

• Curling

• Thermo-insulating

• Permeability

• Knocking

• Etc.

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Single faced fabric- plainTechnical face

Technical backV V V

V V V

V V V

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Single faced fabric

Technical face

Technical back

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Single faced fabric- tuck stitch

O O O

O · O

O O O

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Single faced fabric– tuck stitch

Technical face

Technical back

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Single faced fabric– float stitch

O O O

O - O

O O O

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Single faced fabric– float stitch

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Single faced fabric– tuck and floatstitch

single jerseyhopsackstructure

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Single faced fabric– petinet O O O

O b O

O O O

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Single faced fabric- plush

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Double faced fabric - rib

V O

V O

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Double faced fabric - balanced

V ─ V O ─ O

V ─ V O ─ O

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Double faced fabric

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Double faced fabric – tuck and float stitches

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Tuck stitches

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Double faced fabric – weft insertion

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Purl fabric

V V V VO O O OV V V VO O O O

One course of face stitches

One course of reverse stitches

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Purl fabric - patern

V V V V V V

V V V O O O

V V V V V V

V V O O O V

V V V V V V

V O O O V V

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Purl fabric

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Interlock fabric

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Interlock fabric

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Warp knitted fabrics• Warp knitted fabrics are a product of a technology process carried out on warp knitting machines.

• Their characteristic feature is that the subsequent loops formedfrom the same warp thread are situated in the subsequent courses. This characteristic is the result of the knitting process, which is based on drawing the warp threads simultaneously through the loops in the last formed course.

Principle of warp knitted fabric production

All ends supplied from the same warp sheet have identical lapping movements because each is lapped by a guide attached to the same guide bar.

• same needle, wale

• subsequent courses subsequent

• courses and subsequentwales

Lapping opened

closed

Structure - needle notation

Links recording

Thread of guide bars: Thread of guide bars:

•• full full

•• patternpattern

3

2

0

1

or 3-2/ 0-1//

Schematic stitch drawing

Guide bar moving

• The arrangement of each warp thread in the stitch results from the movements of the guide bar, the guides of which lead the warp threads.

• Sample: opened cord lap

needle notation: 3-2/ 0-1//

1. Shog - behind the needles (1 – 3)

2. Swing - from back to right side (3 – 3)

3. Shog – in front of the needles (3 – 2)

4. Swing - from right to back side (2 – 2)

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Single guide bar warp knitted fabricPillar stitches

Opened lap Closed lap

Needle notation: 1-0/ 0-1// Needle notation: 1-0//

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Single guide bar warp knitted fabric -tricot

Needle notation: 0-1/ 2-1// Needle notation : 1-0/ 1-2//

Closed lapOpened lap

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Single guide bar warp knitted fabric -tricot

Opened tricot

Closed tricot

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Single guide bar warp knitted fabric -cord

Closed lap

Needle notation: 3-2/ 0-1// Needle notation : 2-3/ 1-0//

Opened lap

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Single guide bar warp knitted fabric -cord

Opened cord

Closed cord

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Single guide bar warp knitted fabric -satin

Closed lap

Needle notation: 4-3/ 0-1//

Needle notation: 3-4/ 1-0//

Opened lap

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Single guide bar warp knitted fabric -satin

Opened satin

Closed satin

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Single guide bar warp knitted fabric -atlas

Needle notation: 3-4/3-2/2-1/1-0/1-2/2-3

Opened lap

Closed lap

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Single guide bar warp knitted fabric -atlas

Technical face

Technical back

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Two guide bar warp knitted fabric

In opposition

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Two guide bar warp knitted fabric

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Two guide bar warp knitted fabric

Nets - open work structures

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Laying-in and weft insertionDirectionally orientated structures, warp or weft fibres laid straight, interconnected b stitches. (0°, 90°, +45°, -45°).

Suitable for technical warp knitted textiles with using the special fibres (glass, carbon, etc.)

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Inlay

An inlaid yarn is never formed into a knitted loop. Inlaid fabric consists of a ground structure of overlapped threads that hold in position other non-knitted threads which were incorporated into the structure during the same knitting cycle.

Application: lace and curtain, technical textiles

Pillar and inlay

Needle notation: I. 0-1/ 1-0//

II. 0-0/ 2-2

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Inlay

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Double needle bar warp knitted fabrics

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Double needle bar warp knitted fabrics

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Double needle bar warp knitted fabrics - spacer structures

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Resourses:• Spencer, D.J.: Knitting technology, Cambridge, 2001

• www - firms: Groz-Beckert, Liba, Karl Mayer, Monarch, Mayer&Cie,Stoll, Mueller-frick , Rius-comatex, Shima Seiki

• Lectures ZTOV – FT TUL – czech version

• Kovaříková, M.: Vazby a rozbory pletenin, SNTL 1987

• Daněk, V.: Osnovní pletení, skripta VŠST Liberec, 1984

• Kočí,V.: Vazby pletenin, SNTL, Praha, 1980

• Kovář, R.: Základy pletení, TUL 1998

• Photographs of knitted structures (using with LUCIA) – RomanaZdvihalová, I. Lenfeldová