Flat Singlebed Warp Knitting Machines with Spring Beard Needles
The components operating during the stitch formation cycle on flat single-bed warp knitting machines with spring beard needles are the following the needles - the guide bars - the sinkers - the presser. Picture 131 shows the various steps of the stitch formation cycle and the diagram of the machine movements, which shows the paths of the various components operating during a single revolution of the driving shaft. 1. The needle is in its knock-over position and starts rising the sinker...
Needlebed Racking
The needle-beds of flat knitting machines are not stationary. All flat knitting machines are provided with a needle-bed racking system which is used for shifting one bed in relation to the other by means of a special cam placed on the machine's side picture 36 . Racking can occur in both directions. The needle-bed can also take different positions racking over half needle or full needle. The racking motion allows the creation of inclined patterns right-hand or left-hand on the knit fabric...
The Needlebed
The needle-bed of a knitting machine is made up by the needles. As we said before, the needles can be all fixed on the same needle bar picture 16 or can be driven individually in a grooved plate, according to the type of knitting machine. All knitting machines can be equipped with one or two needle-beds, according to the model. Picture 16 - A needle bar with Picture 17 - The needle-bed of spring beard needles a flat knitting machine Picture 16 - A needle bar with Picture 17 - The needle-bed of...
Terry Knitting Machines
For the manufacturing of terry cloth, it is necessary to use single-bed circular knitting machines equipped with special sinkers featuring a longer nose than standard sinkers and special thread guides which feed simultaneously two yarns, one called ground yarn and the other one called face yarn, into the same needle. During the stitch formation, the sinkers move forward and position themselves between the two yarns. The ground yarn fits under the sinker nose, inside the throat, and carries out...
Circular Knitting Machines Introduction
All over the world, the majority of knit fabrics are manufactured on circular knitting machines. The high performance level of these machines, the different materials and the range of yarn counts that they are able to process, the wide variety of designs and stitches are some of the reasons which have granted circular machines the market leadership in the knitting sector. The variety of knit fabrics that can be manufactured with these machines can meet the needs of a very large end user market...
The Exchange Technique
It is a method for the selection of high-butt and low-butt needles and is mainly used for transferring the stitches from one needle-bed to the other. By using the needles raising cam on the carriage, it is impossible to lead the low-butt needle to the looping position without the upper one doing the same movement. The exchange technique allows this possibility. Near the main group picture 46 made up of a raising cam and a knock-over cam, there is an auxiliary group of cams, consisting of a...
Dialcylinder Knitting Machines
On dial-cylinder circular knitting machines the cylinder is considered the front needle-bed while the dial is considered the rear needle-bed. Both needle-beds feature grooves guiding the needle movements. The needles used for dial-cylinder circular knitting machines are mainly latch needles some manufacturers however use compound needles. Large-diameter dial-cylinder knitting machines can be divided into different categories according to the knitted good they manufacture - circular knitting...
Table of Contents
BASIC General Classification of Knitting The Three Main Types of Needle The Latch Needle The Stitch Formation Cycles with the Three Types of Stitch Formation with a Latch Needle picture Stitch Formation with a Spring Beard Needle picture Stitch Formation with a Compound Needle picture The FLAT KNITTING The Manual Flat Knitting The The The Cam-locks High-butt Needles and Low-butt Knit Stitch Formation Tuck Stitch Miss Stitch Fabric Needle-bed Stitch Automatic Flat Knitting Fabric Take-down...
Needle Specifications
The typical European specifications for a needle includes a word, a number usually a four-digit number and a final combination of letters and numbers. The capital letter at the beginning of the word V , identifies the origin of the needle obtained from a wire, pressed or die-cut , the type, the number of butts and the type of tail. The other capital letters have a very precise meaning, except for the vowels e and a which are added to make the word pronounceable, and indicate the shape and the...
Fleece Knitting Machines
The fleece fabric is similar to jersey and is obtained by inserting one or more additional yarns which do not form the stitch but only a sort of binding on the ground pattern. Single-bed circular knitting machines for fleece fabrics are equipped with a special yarn feed system which must feed the additional yarn into the special fleece feed systems before the formation of the ground stitches. The other feed systems operate as usual and form the ground fabric. From a technical point of view,...
Flat Singlebed Warp Knitting Machines and Singlebed Raschel Machines with
Pictures 133 and 134 show the stitch formation cycle on single-bed machines equipped with compound needles. These machines feature the following working components the needles - the compound needle sliders - the sinkers - the guide bars Picture 133 - Stitch formation cycle on a flat single-bed warp knitting machine equipped with compound needles Picture 133 - Stitch formation cycle on a flat single-bed warp knitting machine equipped with compound needles The different shape of sinkers, which...
Selection Systems
The differentiated selection of needles provides greater possibilities to create patterns with different levels of complexity to meet the needs of a fashion market which requires increasingly sophisticated and innovative garments. Needle selection can be carried out on circular knitting machines with different degrees of complexity from the differentiated control of cams acting on high and low butt needles, to needles with multilevel butts where each butt level matches a cam track , to the...
Basic Structure of a Largediameter Circular Knitting Machine
Circular knitting machines include a number of fundamental elements, based on similar mechanical principles with some small changes according to the different models - The machine base. The most recent trend among circular machine manufacturers is to build knitting machines with a solid yet smaller base and an architecture that facilitates access to the machine components for routine operations to be carried out during setting up procedures and production - The core of the machine, which...
Classification of Warp Knitting Machines
Warp knitting machines can be divided into flat warp knitting machines and Raschel machines. They can have a single or a double needle-bed. Flat warp knitting machines are equipped with spring beard needles or compound needles, while Raschel machines incorporate latch needles or compound needles. The sinkers of flat warp knitting machines feature a nose, a throat and a breast, and pull the fabric perpendicularly to the needle direction. Raschel machines incorporate sinkers with nose only as the...
Automatic Flat Knitting Machines
The structure of an automatic flat knitting machine is very similar to a manual knitting machine. The difference is that the various systems are driven by a motor. The structure of an automatic flat knitting machine is very similar to a manual knitting machine. The difference is that the various systems are driven by a motor. Picture 40 - Automatic flat knitting machine An automatic flat knitting machine incorporates the following systems picture 40 S base B - E reading system to read programs...
Loopwheel Circular Knitting Machines
Loop-wheel circular knitting machines, or mailleuse in French picture 123 , incorporate a circular needle bed in which spring beard needles are arranged horizontally. Loop-wheel circular knitting machines, or mailleuse in French picture 123 , incorporate a circular needle bed in which spring beard needles are arranged horizontally. Picture 123 - A loop-wheel circular knitting machine During the stitch formation cycle picture 124 the needle moves close to the looping wheel. The corresponding...
Takedown and Winding Motions
The fabric take-down and winding motions have been designed to facilitate stitch knock-over and fabric take-down procedures. The take-down and winding functions are kept separated in order to allow a smooth running of the machine and avoid possible fabric distortions. The take-down motion consists of 2 or 3 rollers placed beneath the cylinder. In the simplest system configuration i.e. the two-roller the fabric passes between two rollers that stretch it by rotating in opposite directions....
The Three Main Types of Needle
The needle is the basic element of loop formation. There are three most commonly used types of needle picture 6 the latch needle a , the spring-beard needle b and the compound needle c . We can divide a needle into three main parts A. the hook, which takes and retains the thread to be looped B. the hook opening and closing device, that allows the hook to alternatively take a new thread and release the previous one C. a system allowing the needle to move and form the loop. Picture 6 - The three...
The Yarn Feeding System The Spool Holder
The spools of yarn to be used to manufacture the fabric are arranged on a holder which can be of two different types the circular rack fixed on the upper part the machine , or the lateral creel fixed on the floor beside the machine . On the spool rack, the number of pegs that hold the spools corresponds to the number of the thread guides on the machine. The yarn is conveyed from the spool through some yarn tensioners provided with sensors which monitor the correct feeding tension. The sensors...
The Carriage
The carriage picture 25 is made up of two metal plates linked by a stiff bridge P the plates work individually and simultaneously on the front and the rear needle-beds. The carriage carries out a double function and can be used 1. to select the needles and make them raise or lower to form the stitch 2. to select and drive the thread guides which feed the needles. The plates include cam locks F bearing the drive and control systems of the needles, i.e. the cams. When the carriage moves right- or...
Knit Stitch Formation
The various steps of the stitch formation for the manufacturing of rib knitted cloth are shown in Picture 29. The following description refers to the work carried out by a single needle, however, the carriage activates the needles of both needle-beds. A. The needles are in the knock-over position the loop threads are inside the hook and the latches are closed. B. The carriage moves forward and the cam touches the needle butt. The forward motion of the cam with the tucking cam completely out,...
Highbutt Needles and Lowbutt Needles
The latch needle can have two different butt heights which make it a high-butt needle or a low-butt needle picture 27 . The assembly of high-butt needles and low-butt needles on the knitting machine allows different selection and different manufacturing work ways, according to the positions of the tucking and looping cams picture 28 . Picture 28 - The different positions of the raising cam
Largediameter Circular Knitting Machines
Single-bed Circular Knitting Machines Large-diameter single-bed circular machines are equipped with a single circular needle-bed, with vertical grooves where the latch or compound needles can move. Besides the needles, during the stitch formation cycle special components called sinkers also operate that are positioned perpendicularly to the needles. Sinkers play two fundamental roles they hold the already formed fabric down when the needles rise to knit the new course and support the fabric...
Doublebed Circular Knitting Machines
The most widespread version of double-bed circular knitting machine is equipped with two needle-beds positioned at 90 the vertical needle-bed is called cylinder while the horizontal one is called dial. Another version of double-bed circular knitting machines features needle-beds positioned at 180 these machines are called double-cylinder machines or links-links machines . They incorporate two needle-beds called lower and upper cylinder with the grooves of the two cylinders aligned to one...
Classification by Number of Needlebeds
Another classification parameter for circular knitting machines is the number of needle-beds, which determines the type of stitch that can be carried out 1. Single-bed circular knitting machines for jersey and derived stitches fleece, terry, piquet, floating Jacquard 2. Double-bed circular knitting machines a. Dial-cylinder knitting machines with 90 needle-beds for rib knit and similar cardigan stitches, Milanese rib, bourrelet, Rodier, cable, eyelet and Jacquard stitches, as well as all...
Tuck Stitch Formation
Two consecutive strokes of the carriage are necessary to form the tuck stitch picture 30 . During the first stroke, the tucking cam of the cam is out and the looping cam is not working. Therefore the needle only raises as high as the tucking plane the loop cannot slip on the stem, and therefore remains inside the hook after having completely opened the latch, in this way allowing the yarn to be fed. During the second stroke both the tucking cam and the looping cam are activated the needle rises...
Classification of Knitting Machines
The machines used for the manufacturing of knit fabrics can be divided into machines with individually driven needles and needle bar machines. The former type of machine incorporates needles which are moved individually by cams acting on the needle butt they are used for producing weft knits and are subdivided into circular knitting machines and flat-bed knitting machines. The needles used can be latch needles or compound needles. The needle bar machines incorporate needles which move...
Yarn Feeders
Yarn feeders can be divided into positive or negative types depending on the possibility of controlling the yarn feeding speed and uniformity. A yarn feeder is the negative type when the needle takes the yarn directly from the package during the stitch formation step, and the feeding tension of the yarn cannot be controlled. Picture 78 - A negative yarn feeding device Picture 78 - A negative yarn feeding device This feeding technique can generate differences in the yarn length used for stitch...
Singlecylinder Machines with Needles in the Dial Rib Stitch
The design of single-cylinder machines with needles in the dial partly reflects the design of single-cylinder machines in these machines the hooks in the dial have been replaced with needles to obtain a structure of the knitting head similar to the one of the dial-cylinder machines which produce rib knit patterns. From a technical point of view, the main limit of these machines is represented by the restricted possibility of selecting the needles in the dial as a result of the smaller diameter...
Electronic Jacquard Selection System
The precise definition of this needle selection system for circular knitting machines is electromechanical selection with electronic control, based on the use of piezoelectric actuators that act on the selectors, or of a magnet which commands a striker placed under the needle. Picture 95 - A 16 8 8 level piezoelectric actuator Picture 95 - A 16 8 8 level piezoelectric actuator If the selection is carried out with a single magnet, when the magnet is excited the striker assumes a vertical...
Basic Technology General Remarks
A discussion about knitting technology must be dealt both as an analysis of the technical cycles of knitting as regards the machines used and the mechanisms involved in the process, and as an analysis of the technology of knitted fabrics in terms of their structures and their physical and mechanical properties. In its simplest form, a knit fabric picture 1 is made by the longitudinal and vertical repetition of the same element, the loop, which is the basic element of the fabric. The loop...