Basic principles

A warp knitted fabric with a regular surface and uniform appearance is generally produced when all of the following conditions exist Each bar is fully-threaded, with every guide in the same bar carrying a similar yarn. Each bar makes a regular lapping movement of similar extent at each course. When weft is inserted it occurs with a similar yarn at regular intervals. Warp is supplied to each bar at a constant tension and uniform rate from course to course. Carefully arranged variation of one or...

References

Anon., Where does the name Raschel Machine come from Wirkerei-Und-Strickerei Technik, (1968), Jan., No. 1, p. 11, (translation by C. E. J. Aston). 2. Another possible derivation is from the name Reichel, a German manufacturer who, according to Willkomm (Technology of Framework Knitting, (1885) Part One, page 131) brought the warp loom to Berlin in 1795. 3. wheatley, b., Development of tricot and Raschel machinery over the past 50 years, Knit O'wr. Times Y'r. Bk., (1968), 242-57. 4. cavalca, a.,...

The pattern mechanism

The shogging movement is initiated by varying the radius of the continuously-turning pattern shaft, either in the form of different heights of pattern links that pass over a pattern drum attached to the shaft, or in the form of carefully-shaped solid metal circular cams, termed pattern wheels, attached to it (Fig. 23.3). An increase in height from one link to the next produces a thrust against the end of the guide bar, shogging it positively into the machine a decrease will produce a negative...

Double atlas

In this structure, two guide bars atlas lap in opposition with identically balanced lapping movements, often similarly threaded with colours, in order to produce balanced symmetrical designs including checks, plaids, diamonds and circles. Areas of intense colour are obtained where both overlaps on the same needle are of the same colour, and paler areas are produced by overlaps having two threads of different colours. Repeats of 24 or 48 courses can be made but additional selvedge threads may be...

Gauge

On hosiery machines the gauge is usually expressed as diameter and total number of needles A 4 inch x 400 needle single-cylinder ladies' seamless hosiery machine will have 400 needles to knit plain. (NB the number of needles may be slightly more or less than 400 in order to fit a particular mesh structural repeat exactly around the leg). A 4 inch x 200 needle cylinder and dial machine will have 200 cylinder needles and 100 dial needles. Every second cylinder needle is gated in line with a dial...

Direct and indirect yarn feed

On mechanically-controlled flats, it is necessary to join the front and back needle bed cam-plates with a bow or bridge in order to drive the cam-carriage as a single unit. However, the traversing bow necessitates an unbalanced diversion of the yarn path down to the needles. This in turn produces unbalanced yarn tension, depending on whether the cam carriage is traversing towards or away from its yarn supply. On some of the latest electronically-controlled power flats, the bow has been...

A wale

A wale is a predominantly vertical column of intermeshed needle loops generally produced by the same needle knitting at successive (not necessarily all) knitting cycles. A wale commences as soon as an empty needle starts to knit. When loop transfer occurs it is possible to transfer a wale of loops from one needle A to another B and to recommence knitting with the second needle, in which case more than one needle will have produced intermeshed loops in the same wale. (If needle B knits...

Doublesided plush

Double-sided plush can be obtained using a machine with two sinkers per needle, the face plush yarn being drawn by the throat of a second, specially-shaped sinker placed alongside the plush sinker in each dial trick. Babygro, a special two-way stretch babywear fabric, has been knitted on loop-wheel frames using bearded needles. The plated cotton yarn is pressed-off odd needles at odd feeds and even needles at even feeds to obtain float pile loops. A wide range of plush fabrics in single-jersey...

Jumberca cylinder and dial and doublecylinder machines

The Jumberca cylinder and dial, and double-cylinder machines are electronically-controlled and have almost unlimited selection in the cylinder and dial and in the bottom cylinder of the links-links machine. Stitch length is infinitely adjustable in each bed. The programmable width device adjusts the fabric width to the accuracy of a single needle. Needles are taken out of action so that floating threads join the two fabric edges of the open width fabric this can save up to 15 per cent on yarn....

General rules governing layingin in warp knitting

An inlaid yarn will pass across one less wale than a knitted yarn that has the same extent of underlap. This is because the latter's overlap will add one further needle space traverse onto the underlap movement thus a one-needle underlap will cause a yarn to inlay in the same wale and it will take a two-needle space under-lap to cross from one wale to another. If a guide bar is fully threaded, it will put one less thread between a wale than the number of needles it underlaps. To eliminate the...

Stitch density

Stitch density refers to the total number of loops in a measured area of fabric and not to the length of yarn in a loop (stitch length). It is the total number of needle loops in a given area (such as a square inch, or three square centimetres). The figure is obtained by counting the number of courses or pattern rows in one inch (or three centimetres) and the number of wales in one inch (or three centimetres), then multiplying the number of courses by the number of wales. (Using a measurement...

The takedown system

The conventional V-bed machine relies on the two sets of needles, together with the takedown rollers, to hold the fabric down. The fabric is drawn downwards from the needle beds and passes between the grip formed by the roller and counter roller. The roller is composed of freely-turning sectional rollers on a common shaft. Each roller is pre-set spring-tensioned as the shaft turns under the influence of a racking pawl controlled by a lever and weight arrangement. Adjustable pressure rollers...

The evolution of textiles

Although man's first articles of clothing and furnishing were probably animal skin wraps, sometimes stitched together using bone needles and animal sinews, he soon attempted to manipulate fibrous materials into textile fabrics, encouraged by experience gained from interlacing branches, leaves and grasses in the production of primitive shelters. The word 'textile' originates from the Latin verb texere - to weave - but, as the Textile Institute's Terms and Definitions Glossary explains, it is now...

The development of raschel lace

Karl Mayer introduced the first raschel lace machine in 1956, using 12 guide bars. By 1964,36 guide bars were achieved, followed by 42 in 1968. Electronics began to replace mechanical guide bar control and, in 1981, 42- and 56-guide bar raschels without conventional chains were introduced. In 1985, the first lJacquardtronic, lace raschel with 78 guide bars, electronic pattern guide bar control, and electronic jacquard selection was unveiled. In 1990, the 'TextroniC lace raschel with a...

Conversion formulae

Tex counts may be obtained from count numbers in other systems by using one of the following formulae 886 1938 591 1000 Td NeK NeW NeB Nm 9 (To obtain the decitex count, multiply the tex result by ten.) Example An interlock underwear fabric is weft knitted from 1 40's NeB at a weight of 5 ounces per square yard. Convert the yarn count to decitex and the fabric weight to grams per square metre. (a) The conversion for Tex is 591 NeB so it is necessary to also multiply by 10 to obtain decitex. The...

Sliver or highpile knitting

Sliver or high-pile knitting is single-jersey made on a circular machine having sliver feeds where the stock- or dope-dyed slivers are drawn from cans at ground level. They are then prepared by mini three-roller drafting card units followed by two wire-covered rollers that draw and transfer the thin film of fibres to the needles (Fig. 14.6). At each sliver feed, the needles are lifted to an extra high level where they rise through the wires of the doffer roller to collect a tuft of staple...

The main parts of the bearded needle

There are five main parts of the bearded needle (Fig. 3.2) Fig. 3.2 Main parts of the bearded needle. Fig. 3.2 Main parts of the bearded needle. 1 The stem, around which the needle loop is formed. 2 The head, where the stem is turned into a hook to draw the new loop through the old loop. 3 The beard, which is the curved downwards continuation of the hook that is used to separate the trapped new loop inside from the old loop as it slides off the needle beard. 4 The eye, or groove, cut in the...

Wrapping

Wrapping is a method of producing vertically-orientated patterning with warp threads on a single jersey weft knitted base structure. Specially controlled warp thread guides are used which make unidirectional warp knitted overlaps into selected needle hooks. If selected empty needle hooks rise to receive the warp yarn (as is the case on a few single jersey machines), pure wrapping or warp insertion is produced. If, however, wrapping takes place on needles, all of which already hold a ground yarn...

The doublecylinder slider butt setout

If a broad rib set-out is used whose repeat is not an exact factor of the total cylinder tricks, the extra non-standard rib panels must be carefully arranged to balance at the heel centre (back of the leg) so that they are less noticeable. It may also be necessary for the foot bottom to be slightly less or slightly more than half the cylinder tricks, in order to balance the rib panels on either side of the foot. As previously mentioned (Section 7.5.1), sliders have a needle knitting butt...

The ribtoplain machine

Despite automation in transferring rib border fabric from the V-bed flat machines onto straight bar frames, the operation requires the co-ordination not only of the fabric but also of extra labour and machinery, and involves additional factory space. The rib-to-plain technique 4 pioneered by S. A. Monk tried to overcome these problems. It involves a straight bar frame that can knit an integral rib border start with a less complex mechanical action than that of the conventional rib frame. During...

The advent of nylon

With only yarns such as rayon, silk, cotton and worsted available for knitting, bag-giness (particularly around the ankle) of ladies' fine gauge circular knitted seamless hose caused them to be regarded as a cheap but inferior rival to the more shapely fully fashioned hose knitted on the straight bar frame. The former was even provided with an imitation of the fashionable seam at the back of the leg. There was thus little encouragement for circular hose manufacturers to re-equip and, in 1946,...

Patterned structures

Although noted for the production of plain, classic, fully-fashioned knitwear, the straight bar frame is capable of utilising stitch patterns whose scope is dependent upon the particular machine's facilities. These may include lace, coloured designs, tuck stitches and combinations of these stitches 5 . Lacing points operate in a similar manner to fashioning points. Sets of points fixed in boxes will produce symmetrical effects, whereas individually-controlled points may be used to produce...

Automatic separation

Pneumatic take-down and automatic press-off of seamless hose and socks from single-cylinder machines was a comparatively easier problem to overcome than the automatic separation of half-hose on double-cylinder machines which was achieved by Bentley in 1967. Pressing-off occurs at the point where the draw-thread would normally be introduced when the needles are engaged with the bottom cylinder sliders. The first few needles are raised to non-knit height in advance of the loop-forming position of...

The two types of flat machine

The widely used V-bed rib machine and the slower, more specialised flat bed purl or links-links machine. V-bed machines have two rib gated, diagonally-approaching needle beds, set at between 90 and 104 degrees to each other, giving an inverted V-shape appearance. Flat bed purl (links-links) machines have horizontal needle beds. They have been employed mainly in knitting simulated hand-knitted constructions of a speciality type, such as cable stitch, basket...

Conversion from Cottons Patent to Vbed gauge

To convert from Cottons Patent gauge (G*, needles per 1- inch) to V-bed gauge (E, needles per inch) 1 Convert from 1- inches to 1 inch needle bed width. 2 In the gauge range G9 and below, reduce the resultant E gauge by 1. Above G 9 reduce the resultant E gauge by 2. This is to fit commercial practice in flat knitting, where a slightly coarser gauge is preferred. Example Convert G9 and G21 fully-fashioned (needles per 1- inches) to V-bed flat E gauge (npi)

Upright loop structures

Structures with upright loops in straight wales are produced only if the tension on the yarn on either side of the needle loop head is balanced. This condition often exists in weft knitted structures because balanced sinker loops enter from either side of the needle head, but it may be disturbed by racking, by knitting twist lively yarn or by traversing pressing-down elements. Warp knitted structures, however, seldom have perfectly upright overlaps because the underlaps, even if they enter from...

The Mac Queen concept

In the early 1960s, Kenneth MacQueen unsuccessfully attempted to develop a revolutionary electronic computer-controlled V-bed flat machine having compound needles 4 . The idea was to use the Basque beret technique of knitting wedge-shaped garment parts in a sideways manner with held loops, part course knitting, and sections separated by waste yarn segments. The machine was to use a variable carriage traverse, magnetically-energised raising cams to lift the needle butts, tape control for the...

The needle

The hooked metal needle is the principal knitting element of the knitting machine. Prior to yarn feeding, the needle is raised to clear the old loop from the hook and to receive the new loop above it on the needle stem. The new loop is then enclosed in the needle hook as the needle starts to descend. The hook then draws the new loop down through the old loop as the latter slides over the outside of the descending bridge of the closed hook. All needles must therefore have some method of closing...

Fulldensity patterned plush

The durability of plush fabrics is strongly influenced by the density of the pile. In plain, single-colour pile there is an optimum pile density of one pile loop to each ground loop. When knitting patterned plush (either in colour or self-colour with different plush heights), optimum pile density cannot be achieved. The reason is that, although the plush yarn plates with a complete ground course on the technical face side, it only produces a part course in pile on the effect side. Mayer and Cie...

The range of speciality fabrics

Speciality fabrics include fleecy, plush, high pile and wrap fabrics. Although some constructions are unique to a single type of circular machine, others may be knitted on a range of machinery. The surface effects of fleecy, plush or pile are developed during the finishing process usually on the technical back of single faced fabric. In fleecy fabrics, the fleece yarn fibres (usually in the form of inlaid yarn) become entangled and indistinguishable from the base yarn on the effect side,...

Spot or knop effects

Spot or knop effects require the use of both a plain presser and a cut presser (Fig. 27.11). The front and back guide bars might be full-threaded and knit a locknit or reverse locknit in co-operation with the plain presser. At various selected points in the production of the fabric, these two bars stop overlapping and the plain presser is withdrawn so that the cut presser operates in conjunction with a partly-threaded middle guide bar to make the knop overlaps. Adjacent needles hold their...

The properties of warp knitted structures

Higher production rates than for weaving. A wide variety of fabric constructions. A low stress rate on the yarn that facilitates careful handling of fibres such as glass, aramide and carbon (particularly when using weft-insertion techniques). Conventional warp knitted structures that can be directionally structured. Three-dimensional structures that can be knitted on double needle bar raschels. With weft insertion, uni-axial, bi-axial, multi-axial and composite structures that can be...

Flat machine gauges

Flat machines (Fig. 8.2) are normally gauged on the English system (e) of needles per inch (npi). The Metric system, which is based on the distance in tenths of a millimetre from the centre of one needle to the next, is rarely used. The latter is a direct system, with a higher gauge number indicating a coarser gauge - the opposite of the English system. Generally, flat machine gauges range from E 5 to E 14, with the main gauges being 5,7 and 10, but there are machines as coarse as E 2- and as...

Design appearance requirements

The terms technical face, technical back, and upright are purely technically descriptive terms. They do not necessarily indicate the orientation of the fabric from the designer's viewpoint. For example Socks and ladies hosiery are usually worn upside-down compared to their sequence of production. The technical back of structures is often used for plush and pile effects. Curtains may be hung sideways compared to the wales. Diagonal stripes may be achieved for dress-wear by cutting the fabric at...

Types of doublejersey structure

There are two types of double-jersey structure - non-jacquard structures, knitted mainly on a type of modified interlock machine, and jacquard structures, produced on rib jacquard machines (The latter are covered in Section 10.4.4). Various modifications to the interlock machine have been necessary in order to produce the new structures. Originally, only alternate tricks were fully cut through to accommodate long needles so that mock eight-lock was achieved by knitting normal interlock with...

Preface

The aim of this book is to combine in a single volume the fundamental principles of weft and warp knitting in such a manner that its contents are useful to readers in education, industry or commerce. It thus fulfils the long felt need for a comprehensive up-to-date textbook explaining this important sector of textile technology. Aspects covered include flat, circular, full fashioned, hosiery, Raschel, tricot and crochet production. The inclusion of the historical development of the types of...

Further information

M., A Handbook of Textiles, (1974), Pergamon Press. lOSEPH, M. l., Introductory Textile Science, (1966), Rinehart and Winston. greenwood, k., Weaving Control of Fabric Structure, Merrow, UK. lord, p. r. and mohamed, m. h., Weaving Conversion of Yarn to Fabric, (1976), Merrow. cooke, i. g., Handbook of Textile Fibres, (1968), Merrow, UK, I, II. morton, w. e. and hearle, i. w. s., Physical Properties of Textile Fibres, (1975), Textile Inst., Manchester, UK, and Heinemann, London, UK....

Separation

Knitted articles are often produced separately on single-cylinder machines, Cottons Patent machines and some flat machines. Others are knitted in continuous string formation on many flat and circular rib and purl machines because fabric tension-ing is dependent on a continuous length of fabric between the needles and the takedown rollers. Also, there would be a danger of latches not being open at the start of a new garment sequence. If the string of garments is separated by cutting, there is a...

The manufacture of hosiery on smalldiameter circular machines

For centuries the production of hosiery was the main concern of the knitting industry. The prototype machines for warp, circular, flat and fully-fashioned knitting were all originally conceived for knitting hosiery. Nowadays, however, hosiery production is centred almost exclusively on the use of small-diameter circular machines. In single cylinder and fine-gauge hosiery particularly, much of the latest development is centred in Italy. One company - Lonati - has acquired a major portion of...

Uses of loop transfer

The object of loop transfer is to achieve shaping, produce a design, or change the stitch structure. In addition, loop transfer is used in ladies' stockings, when producing the double-thickness, plain fabric, in-turned welt, in running-on and doubling rib loop fabric onto the needles of a straight bar frame to form the rib border of a garment part, and when running the loops of two separate fabrics onto the points of a linking machine for linking these fabrics together. Loop transfer by...

Float plating

Float plating (Fig. 9.3) produces an open-work mesh structure in single jersey and involves feeding two yarns in a plating relationship to needles having forward hooks. A thick yarn (A), for example 30 denier, is fed at a high level and is received only by needles selected to that height. A fine yarn (B), possibly 15 denier, is fed at a lower level and is received and knitted by every needle. Two -course fishnet is the most popular structure, having a repeat of two wales and four courses deep....

Positive needle control

Positive guiding of needles through a cam system can be achieved on circular machines knitting plain unpatterned fabrics. In cam systems on jacquard machines, needle butts have to be switched to a choice of cam-tracks. At this point they cannot be under positive control so the cam-track is open. To reduce the chance of the unguided needle butt moving to a wrong position, needle movement is slowed down by using one or more of the following methods Reducing the machine speed. Using friction...

The chain links

In plan view, the identically Y-shaped chain links are similar in appearance to a tuning fork with the fork end leading. The tail of the preceding link fits into the fork of the succeeding link. The links are held together by pins that are pushed through holes in the sides of the fork and tail. The pins pass through all the tracks and chains, and the ends fit into grooves in the serrated flanges of the pattern drum so that as the drum turns, the chain links are advanced in unison in a correct...

Layingin and weft insertion

Laying-in is achieved in warp knitting by causing a guide bar to only underlap its threads will be held in the technical back of the structure only if a guide bar in front of it is overlapping. The yarn will inlay on top of the overlaps during knitting so that, as the guides of the knitting bar swing through the needles for the next overlap, their underlaps will be laid on top of the inlay yarn, trapping it into the back of the fabric (Fig. 27.1). An inlaid yarn may pass across part or all of...

Circular warp knitting

Tubular, seamless, extensible nets for fishnet patterned stockings, fruit sacks, and medical support bandages can be knitted on simple, small-diameter circular warp knitting machines. The vertical latch needles are fixed to the needle cylinder, collectively rising and falling with it. They are in a conical arrangement so the hooks form a smaller circle than the stems. The warp yarn is supplied through guide-eyes drilled in a ring. The ring turns to overlap the hooks when the needles are raised...

The welt

The turned welt of doubled plain fabric that is produced on stocking frames is usually less acceptable for the start of a garment panel - a rib border is often preferred. Straight bar rib frames have been built but they have proved to be complex and uncompetitive against faster and more versatile V-bed rib flat machines. A popular technique is to knit the rib borders or cuffs on a specific-purpose V-bed flat machine and then to transfer them, using the last required course, loop-by-loop onto...

Seamed toe closing

Linking is the conventional method of toe closing that occurs after knitting during making-up. A slacker course of loops on the instep is joined loop-to-loop to a similar course in the toe pouch, by stitching on a linking machine. This is, however, an expensive, relatively slow and skilled operation. In Rosso linking, the fabric to be joined is guided by a conveyor guide onto dial points and is seamed from opposite sides, but the join is not exactly on one course nor is there an individual...

The potential of knitting technology

The unique loop structure of knitting provides opportunities for using a minimum number of yarns. easy flow of yarn from one loop to another under tension. loop distortion when under tension. knitting single face, double face, open-work and surface interest structures. increasing or decreasing the number of loops in width or depth. knitting to shape either fabric pieces or separate articles. knitting from a selection of yarns. engineering extensibility or stability. introducing (by inlay) yarns...

The spread of knowledge of hand pin knitting

Weft knitting, using the fingers to produce open loop structures, may well have been practised long before the use of hand-held pins. Hand pin knitting was first recorded in religious paintings in 1350 in Northern Italy. It then spread through the rest of Europe 2 . Maitre Bertram's painting of Mary knitting Christ's seamless garment (Fig. 2.1) is dated to just before 1400. Unfortunately, Christ's garment is more likely to have been made by the 'sprang' or braiding technique, in a similar...

Machine knitting

Knitted structures are progressively built-up from row after row of intermeshed loops. The newly-fed yarn is converted into a new loop in each needle hook. The needle then draws the new loop head first through the old (fabric) loop, which it has retained from the previous knitting cycle. The needles, at the same time, release, (cast-off or knock-over) the old loops so that they hang suspended by their heads from the feet of the new loops whose heads are still held in the hooks of the needles. A...

Single and doublejersey compared

Single-jersey fabrics are mostly knitted on latch needle sinker top machines. These machines have a simpler construction than cylinder and dial machines, are easier to supervise and maintain, have higher running speeds and more feeders, and knit a greater range of structures with a wider tolerance of yarn counts. In Europe, double jersey was generally preferred to single jersey, particularly for ladies' wear, because of problems of dimensional stability, structural breakdown, air porosity and...

Microprocessors and computers

The most important use of electronics is in microprocessor and computer systems. A computer can receive, store, retrieve, and communicate enormous quantities of information at phenomenal speeds. It can also manipulate, rearrange, select, and transform this information. It performs arithmetical or logical processes accurately at high speed after receiving the instructions (programme) and values (data) without the need for further intervention by the operator. Flexibility in processing of data...

The advantages of electronic control and programming

Electronics offer the decisive advantages of convenient power-supply, compatibility with existing mechanical components, micro-miniaturisation of circuitry, and economical data storage. In addition, electronic systems do not require to be of a size proportionate to their task or to operate on a one-to-one relationship with it. Electronic selection or machine control is compatible with higher running speeds and eliminates complex mechanical arrangements, thus reducing supervisory requirements....

The disadvantages of mechanical programming

Mechanical pattern and programming data for controlling knitting machines is stored in the form of punched cards, chains, rack-wheels, peg drums, and element butt arrangements. These are expensive in material, bulky in space on the machine or in storage, time-consuming to handle and alter, slow in operation, and provide restricted facilities. Hydraulics, fluidics, and electronics provide alternative systems of power transmission and signal storage with the requisite speed and precision.

Pattern wheel design areas

The principles governing design areas apply to all wheel selections, including sinker-wheels with plush and plain plating sinkers, provided that their set-out remains unchanged during knitting (Fig. 11.10). The wheels are generally of the same size and gauge on the same machine. The needle producing the starting wale of the design is marked and, as the cylinder turns during the first revolution, it will align with the marked starting trick of each wheel in turn, to ensure that their selections...

The pattern wheel

The pattern wheel is a cheap, simple device occupying little space, and is unique in employing separate raising cams, in the form of pattern bits, to select and move individual elements, if necessary, to three different positions in their tricks (Fig. 11.9). It is most popular in single-jersey machines, either as an inclined wheel for needle or point selection, or as a horizontal wheel for plush sinker selection. The pattern set-out, which is unchanged during knitting, uses bits which are...

Needle selection by disc

The Mellor-Bromley rib jacquard (RJ) system uses revolving stacks of discs at each feed selection position. The replaceable disc stacks are rotated in unison with the machine drive. On 72-feeder machines, the stacks are accommodated at two alternately staged heights. When a disc tooth contacts the bottom half-butt of a presser (X in Fig. 11.7), it causes the jack tail (Y) which supports it to be retracted into the cylinder so that its tail butt misses the raising cam (Z) and the needle which is...

Selection area arrangement

Inch Round Cake Feeds How Many People

Dependent upon the type of device, four arrangements of the selection areas around 1 Full jacquard selection can produce a selection area of theoretically unlimited depth and a width equal to the number of needles in the cylinder, so that the design exactly surrounds the fabric tube without repeating. 2 Pattern wheels have a circumference selection that is not an exact factor of the number of cylinder needles, so that their selection areas follow the spiral path of the feeder courses around the...

Selection devices

Selection devices vary considerably in their facilities and their pattern-changing and pattern-area capabilities. A selection device is positioned to operate in advance of a raising cam system (usually associated with a knitting feed position) to select the path that the element operating butts will follow as they pass through that system. Each possible path will cause the element to be moved in a different manner, resulting in the knitting of a different type of stitch. Usually, a selection...

Multistep butt setouts

Although some selection devices, including pattern wheels, operate onto element butts of one height position, many patterning arrangements involve the use of a single selection butt for each element, placed at one of a choice of height positions. The total number of different heights often directly influences the width repeat in wales. It is generally most convenient to arrange and retain a butt set-out that is a factor of the needle bed, so that the pattern widths exactly repeat into it. The...

Different lengths of butt

Whereas butts of normal length extend into the track formed between cams and guide their elements by contact with the profiled edges, a butt of shorter length may not reach into the track and will thus pass across the face of the cam and be unaffected by its profile (Fig. 11.1). The same principle is employed when cams are withdrawn into their cam-plate or the elements are depressed into their tricks, thus reducing the effective length of their butts. The principle of butt lengths is that the...

Pattern guide bars

On conventional multi guide bar machines, pattern guide bars are only required to supply one thread each for a pattern repeat width. Different yarn counts or types are used to achieve greater effect. To use ordinary guide bars for this purpose would be uneconomical as their weight would lower the machine speed. Also, only about eight to thirteen shogging or displacement positions are available so the patterning capabilities would be severely restricted. Instead, light-weight pattern guide bars...

Multibar tricot lace machines

Multi guide bar tricot machines with between eight and eighteen guide bars have been built in gauges of E 24-28 for the production of fine gauge lace 2 . Two fully-threaded bars are used to knit the ground, such as reverse locknit or queenscord, with fine yarn such as 44 dtex nylon. Pattern bars behind the ground bars are used for inlay effects. Those in front are employed for embroidery designs in the form of overlaps and underlaps, in a textured yarn so that they stand out in relief on the...

Chain links and electronic control of shogging

The cost of chain links and the labour involved in chain assembly are major problems with multi guide bar machines. Ground guide bars are generally controlled directly from links or pattern wheels moving at two links per course (A). The pattern guide bars are controlled indirectly through shogging levers (B) (Fig. 28.2), using only one link per course (either they only inlay or they are caused to automatically overlap in the same direction after the underlap is completed by an eccentric working...

Jacquard raschels

Although first patented by Samuel Draper of Nottingham in 1837, the selective control of individual guide lapping in a guide bar by means of an overhead jacquard only developed into a sophisticated technique during the late 1960s. On Karl Mayer machines using mechanical jacquard control, the principle employed was to deflect selected guides in a fully-threaded jacquard bar guide bar by means of selectively lowered dropper pins carried in a separately-shogged displacement pin bar. Those guides...

Productivity

Productivity (P) is expressed in pattern rows per minute. In warp knitting this is the same as courses, but in weft knitting a pattern row may be composed of more than one course (feed). In warp knitting, P R x e, where R is the number of camshaft revolutions per minute and E is the machine efficiency. In weft knitting, P F x R or T x (e c), where F is the number of active yarn feeds, R or T the number of machine revolutions or cam-carriage traverses per minute, and C the number of courses or...

Machine design

In warp knitting machines, all elements of the same type (needles or sinkers or guides of one guide bar) act as a single unit and are therefore fitted into, and controlled from, an element bar. Each guide in the same (conventional) guide bar requires the same warp-yarn feed rate and tension. This is most conveniently achieved by supplying a large number of parallel ends of warp yarn to the guide bar from a warp beam. The shogging movement of the guide bars is controlled from one end of the...

Fabric quality

The term fabric 'quality' is sometimes used when referring to wales and courses per inch or centimetre, either in a knitted or a finished relaxed state. As knitted loops tend to assume a recognizable configuration, the results can give an indication of the approximate stitch length and possible machine gauge used in knitting the structure, provided the state of relaxation and type of structure is taken into consideration. Generally, the higher the figure for a given linear measurement of wales,...

Introduction

Four primary structures - plain, rib, interlock and purl - are the base structures from which all weft knitted fabrics and garments are derived. Each is composed of a different combination of face and reverse meshed stitches, knitted on a particular arrangement of needle beds. Each primary structure may exist alone, in a modified form with stitches other than normal cleared loops, or in combination with another primary structure in a garment-length sequence. All weft knitted fabric is liable to...

History

In 1867, Henri Edouard Dubied acquired the European rights for Lamb's machine (see Section 18) during the Paris Exhibition and established his knitting machine building company. Similarly, in 1873, Heinrich Stoll, a German engineer, began to build and repair Lamb machines and by the early 1890s he was not only building improved versions of the rib machine but also flat bed purl machines of a similar standard of perfection 1-3 . The company founded by Stoll continues to play an important part in...

The three methods of forming yarn into needle loops

There are three methods of forming the newly-fed yarn into the shape of a needle loop 1 (Fig. 4.1) - by sinking the yarn into the space between adjacent needles using loop forming sinkers or other elements which approach from the beard side. The action of a straight bar frame is illustrated. (Other obsolete circular bearded needle machines such as the sinkerwheel and loopwheel frame employ the same technique.) The distance SL, which the catch of the sinker moves past the beard side of the...

The main features of the knitting machine

Originally, the term 'machine' used to refer to a mechanism on a bearded needle frame such as the fashioning mechanism on the straight bar frame. Today, it refers to the complete assembly. A knitting machine is thus an apparatus for applying mechanical movement, either hand or power derived, to primary knitting elements, in order to convert yarn into knitted loop structures. The machine incorporates and co-ordinates the action of a number of mechanisms and devices, each performing specific...

Fullyfashioned articles

Excepting knitwear, which is a comparatively recent development, fully-fashioned or wrought products have suffered a considerable decline in fashion demand during the twentieth century as a result of the improvement of cheaper manufacturing techniques in other sectors of weft knitting including, more recently, the development of heat-set shaping based on the use of thermoplastic fibre yarns such as nylon. Fully-fashioned half-hose and socks were the first to be replaced by circular knitted...

Course length and runin per rack

In weft knitting, the term 'course length' refers to the measurement of a straight length of yarn knitted by all or a fraction of the needles in the production of a particular course. It consists of the stitch length multiplied by the number of needles knitting that stitch length. It may be measured at a yarn feed during knitting or after unroving the yarn from a knitted fabric, either as a complete course length or from the counted wales between two vertical cuts in the fabric. In Fig. 6.1,...

The two industries

Occasionally parts of both knitting techniques are combined in a single machine generally, however, the techniques have tended to diverge to produce entirely separate industries each having its own specialist technology, machine builders, fabric characteristics and end-uses. Weft knitting is the more diverse, widely spread and larger of the two sectors, and accounts for approximately one quarter of the total yardage of apparel fabric compared with about one sixth for warp knitting. Weft...

Markets for technical textiles

Anand of Bolton Institute, England, technical textiles account for approximately 21 per cent of all textiles. The main markets are traditional industrial fabrics, for example, canvas, tents, etc. (43 ) transportation and automotive (23 ) leisure (12 ) geotextiles (10 ) medical textiles (10 ) and protective apparel (2 ). Two-thirds of automotive materials go into 'interior trim' for seat covers, roof and door liners, and carpets, where woven fabrics still dominate 2 ....

Springloaded cams

Raising cams (R) and cardigan cams (C) (Fig. 18.3) are of the spring-loaded type that can be depressed into the under-surface of the cam-plate against the action of a spring. The leading edge of a leading raising cam is straight so that it causes the butts to follow its profile. However, the trailing inner edge of the cam, which is the leading edge when that cam is trailing, has a gently sloping edge. Needle butts deliberately not raised by the leading cam thus ride up the trailing cam,...

Timing and control of mechanical changes on circular hosiery machines

Air Brake Compressor Cut Away Picture

The application of microprocessor controls has removed the need for mechanical timing chains and control drums on the latest electronically-controlled hosiery machines. The machine's microprocessor memory can accommodate a range of sizes and styles that can be quickly recalled when a change is required. On mechanically-controlled machines, the changes are timed by the links of a timing chain that also control the racking of a control shaft to which are attached the control cam-drums and wheels...

Knitting motions of the straight bar frame

The three directions of motion required for the knitting action are provided from two separate sources. The rotary motion of the cam-shaft produces the vertical and horizontal movement of the fashioning points and the needle bar. The sideways reciprocating movement for the yarn carriers and for introducing the sinkers in serial sequence via the slurcock is obtained from a coulier or draw cam attached to a shaft, set at right angles to the main cam-shaft at the back of the machine, which...

Fabric machines and garmentlength machines

Weft knitting machines may be broadly grouped according to end product as either circular machines, knitting tubular fabric in a continuous uninterrupted length of constant width, or flat and circular machines, knitting garment-length sequences, which have a timing or counting device to initiate an additional garment-length programming ('machine control') mechanism. This co-ordinates the knitting action to produce a garment-length structural repeat sequence in a wale-wise direction. The garment...

The evolution of other weft knitting machines

The fineness of the needles and sinkers relied heavily on the developing skills of English mechanics, a skill which was lacking on the continent of Europe at that time. Lee's original invention, although workable, was not economically viable as it required two men to operate it. Improvements were carried out and by 1620, Aston, a former apprentice of Lee's, had arranged the sinkers into alternating sets and thus, with skill and precision, had obtained better uniformity of loop length, much...

The compatibility of electronic signals and knitting data

Electronic devices process information as binary digital logic signals that exist in two states, ON or OFF. This can be directly translated as 1 or 0, YES or NO, TRUE or FALSE, or magnetic ATTRACTION or REPULSION. This information can just as conveniently be translated into knitting states such as KNIT or TUCK, TUCK or MISS. The binary digits can be arranged in the form of a programme where they can be encoded and converted into symbols to compose, for example, a knitting design or a machine...

The five basic overlapunderlap variations

Over Lap Knitting

All guide bar lapping movements are composed of one or more of the following lapping variations (Fig. 23.5) 1 An overlap followed by an underlap in the opposite direction (closed lap) (Fig. 23.5a). 2 An overlap followed by an underlap in the same direction (open lap) (Fig. 23.5b). 3 Only overlaps and no underlaps (open laps) (Fig. 23.5c). 4 Only underlaps and no overlaps (laying-in) (Fig. 23.5d). 5 Neither overlaps nor underlaps (miss-lapping) (Fig. 23.5e). Movements 4 and 5 require the...

Guide bar nesting

Up to four pattern bars can be 'nested' together so that their guides converge into the same displacement line. They swing as a single guide bar but they are shogged independently, although guides of bars in the same nest cannot cross or approach within two needle spaces of each other Fig. 28.3 . On the 42-bar lace raschel, thirteen displacement lines are available. The front two are conventional guide bars for knitting the ground, the next may be a conventional bar for draw-threads when...

The open lap

An open lap is produced either when a subsequent underlap is in the same direction as the preceding overlap Fig. 5.5 or an underlap is omitted so that the overlap of the next knitting cycle commences in the needle space where the previous overlap finished. Closed laps are heavier, more compact, more opaque, and less extensible than open laps produced from the same yarn at a comparable knitting quality.

Tightness factor

Munden first suggested the use of a factor to indicate the relative tightness or looseness of plain weft knitted structure, to be used in a similar manner to that of the cover factor in the weaving industry. Originally termed the cover factor but now referred to as the tightness factor TF , he defined it as the ratio of the area covered by the yarn in one loop to the area occupied by that loop. The total area covered by yarn is S x l x d, if l is loop length in mm and d is yarn diameter in mm...

Weft knitted patterns

Generally, patterns are produced in weft knitted structures either in the form of selected colours for face stitches or surface relief patterns based on a choice of different types of stitch. As illustrated in Fig. 3.4, the height to which a latch needle is lifted in its trick determines which stitch will be knitted. If all needle butts are in the same position on the needle stems and they pass over the same cam profile, a plain fabric will be knitted, with all stitches having the same...

Doublefaced structures

Double-faced structures are produced in weft and warp knitting when two sets of independently-controlled needles are employed with the hooks of one set knitting or facing in the opposite direction to the other set. The two sets of needles thus draw their loops from the same yarn in opposite directions, so that the fabric, formed in the gap between the two sets, shows the face loops of one set on one side and the face loops of the other set on the opposite side. The two faces of the fabric are...

Production of heels and toes

Three-dimensional 'turned' heel and toe pouches Fig. 21.4 are knitted in plain so that, in the case of double-cylinder machines, the heel section needles must be transferred down to knit from the bottom cylinder. A spring take-up holds the surplus yarn as the needles traverse towards the feed on the return oscillation, whilst a pouch tension equaliser ensures that the pouch fabric is held down on the needle stems. The pouch is preferably knitted in single feed so that the other feeds if there...

Terry by the pressoff method

The press-off method has proved particularly suitable for knitting terry fabrics for towelling and fitted bed linen. A compound needle tricot machine has been spe cially developed for the technique. In the needle bar, which is in the gauge range E 20 to E 24, normal compound needles alternate with large-head needles.The guide bars are threaded I I with the ground guide bar overlapping only the normal compound needles and the terry guide bar overlapping only the large-head needles. In the latter...

Plain tricot structures knitted with two full set guide bars

Plain tricot structures knitted with two full set guide bars are by far the most popular of all warp knitted structures and are mainly based on a two-course repeat cycle with a change of direction lap at each course.Although the majority have been made on 28-gauge tricot machines using 40 denier nylon, other gauges, yarn types and counts, and also raschel machines, are used. The two bars make different lapping movements because, if they were both to make the same lapping movement a structure...

The underlap

The underlap shog occurs across the side of the needles remote from the hooks on the front of single-needle bar, and in the centre of double-needle bar, warp knitting machines. It supplies the warp yarn between one overlap and the next Fig. 5.3 .The underlap shog generally ranges from 0 to 3 needle spaces, but it might be 14 needle spaces or more depending upon the design of the machine and the fabric structure although efficiency and production speed will be correspondingly reduced with long...

Coloured stitch designs in weft knitting

Colour is one of the five ingredients of fashion, the other four being style, silhouette, texture and pattern 1 . Ornamentation for design purposes may be introduced at the fibre, yarn, or dyeing and finishing stage, as well as at the knitting stage. Apart from different colours, it may take the form of sculptured or surface interest. In fibre form it may include a variation of fibre diameter, length, cross-section, dye uptake, shrinkage, or elastic properties. In yarn form it can include fancy...

Partthreaded guide bars

Lap Diagram For Tricot Machine

The following are the basic rules when employing part-threaded guide bars for the production of nets, cords and relief designs During a normal knitting cycle, every needle must receive at least one overlapped thread but it is not necessary for the same guide bar to supply every needle or for every needle to be overlapped by the same number of threaded guides. The guide bar threading for one width repeat is usually shown in its correct relative position between the needle spaces at the first...

The crochet machine

Machine Crochet Muller Fonctionnement

In hand crocheting, a hook is used to draw a new loop through the old loop with the chains of loops being joined together at intervals. On crochet machines, the warp chains are separate from the weft inlay and it is the latter threads that join the chaining wales to each other. The crochet galloon machine, as developed by Sander and Graff and popularised by Kholer, is essentially a highly versatile raschel with the following unique features Figures 24.8 and 24.9 A single horizontal needle bar...

Knitting technology The fashioning action

Figure 17.5 a-f illustrates the fashioning action for either narrowing or widening a The fashioning points descend and the needle bar tips backwards to clear them. b The needle bar moves towards the points, causing the beards of the needles engaged with points to be pressed and 'boxed' or located in the grooves of the points. c The sinkers and dividers, which are collectively controlled by the catch bar, retire, and the needles and points descend together below the knocking-over bits, so that...

The two methods of yarn feeding

Knitting Mechanism

As mentioned in Section 4.3.2, yarn feeding involves either a moving the needles past the stationary yarn feed or b moving the yarn past the stationary needle bed. When the yarn moves past the needles, the fabric will be stationary because the loops hang from the needles. This arrangement exists on all warp knitting machines, and on weft knitting machines with straight beds and circular machines with stationary cylinders and dials. On straight machines of both weft and warp type, the...

Computer graphics and pattern preparation

Of all knitting machines, the modern electronic V-bed flat machine, with its comprehensive patterning and garment shaping facilities, offers the greatest challenges as well as the greatest opportunities for the application of a CAD CAM system Fig. 12.3 . Interactive computer graphics enables a dialogue to occur between the operator terminal and the system, with the resulting development of the design being immediately visually represented on the screen. The position is defined and located by...

Calculate The Fashioning Sequence For A Kintted Panel

Integral Knitted Garments

Fig. 16.9 Integrally shaped rib garment pieces. The machine has an additional bed containing the transfer points Shima Seiki . 2 Convert the width dimensions at the start of each section to total numbers of needles by multiplying the width measurement by wpi. Thus, 16 x 16 256 18 x 16 288 8 x 16 128 needles. 3 Calculate the total number of needles increased or decreased from one section to another by taking one total from the next. 4 Divide the totals obtained by 2 in order to obtain the...

Enduses for technical textiles

Adidas Fullbody

Possible specific applications for technical textiles are as follows Geotextiles - Drainage, filter, and membrane material, road and tunnel reinforcement, erosion protection. Tarpaulins, coverings - Air-inflated structures, tarpaulins, roof coverings, temperature-resistant sails, back-lit advertising signs. Safety textiles - Heat and flame-resistant protective clothing for civil and military purposes, fluorescent safety clothing, inflatable life rafts, bullet-proof vests, helmets, sun...