Fabric Club Of BD: 08/01/2011

INTERLOCK STRUCTURE

Labels: Knitting Manufacturing Technology | at 8/25/2011 09:30:00 PM

Interlock structure

Interlock has the technical face of plain fabric on both sides, but its smooth surface cannot be stretched out to reveal the reverse meshed loop wales because the wales on each side are exactly opposite to each other and are locked together (fig). Each interlock pattern row requires two feeder courses, each with a separate yarn that knits on separate alternate needles, producing two half-gauge 1 x 1 rib courses whose sinker loops cross over each other. Thus, odd feeders will produce alternate wales of loops on each side and even feeders will produce the other wales.

Figure. Interlock fabric structure.

►There are TWO type of needle arrangement in circular machine.

►When the needle heads are offset with each other, it is called rib gating e.g. 1x1 ribs, 2x2 ribs.

►If the needle heads are facing with each other, it is called interlock gating, e.g. interlock fabric

Construction of interlock stitch

A knitted fabric is obtained which is characterized by situating loops of one course in every second wale, as these loops are formed on every second needle. Loops of the next course are also situated in every second wale, formed on needles that had not formed loops in the previous course. Thus loops of consecutive courses, formed in every second wale, are shifted in relation to each other by half of their height. An example of the stitch construction described is shown in Figure.

Figure. Warp-knitted interlock stitch.

A group of knitted fabric stitches produced according to the above-mentioned technology may be referred to as warp-knitted interlock stitches, as they are similar to the weft-knitted interlock stitches. The loops of one stitch are situated between loops of the other.

Anticipating the merits of some end-use properties of fabrics with the new stitches, the relationships between the structure of these stitches and some of their end-use properties are to be examined. The features of warp-knitted interlock fabrics have been compared to warp knitted fabrics with stitches applied so far.

An analysis of the production method of knitted fabrics according to the proposed technology led to the observation that warp-knitted interlock stitches can be obtained on warp-knitting machines with latch needles, equipped with a tuck presser.

Figure. An example of the warp-knitted interlock stitch, produced on a warp-knitting machine equipped with a tuck presser.

Machine requirement for interlock knit fabric

►Interlock fabrics are mainly produced on specially designed circular double jersey machines called interlock machines.

►They are high speed, multi-feeders with closed cam track machines.

►The common gauges for interlock fabrics are 20-24 npi, using 1/30 Ne cotton or 1/48 Nm worsted yarns.

►Worsted interlock is for ladies’ winter suiting fabrics. For those 28 gauge fabrics, the yarns used are mainly textures polyester of 75 denier.

CAM

Labels: Weaving Manufacturing Technology | at 8/21/2011 04:42:00 PM

Cam mechanism

The transformation of one of the simple motions, such as rotation, into any other motions is often conveniently accomplished by means of a cam mechanism A cam mechanism usually consists of two moving elements, the cam and the follower, mounted on a fixed frame. Cam devices are versatile, and almost any arbitrarily-specified motion can be obtained. In some instances, they offer the simplest and most compact way to transform motions.

A cam may be defined as a machine element having a curved outline or a curved groove, which, by its oscillation or rotation motion, gives a predetermined specified motion to another element called the follower. The cam has a very important function in the operation of many classes of machines, especially those of the automatic type, such as printing presses, shoe machinery, textile machinery, gear-cutting machines, and screw machines. In any class of machinery in which automatic control and accurate timing are paramount, the cam is an indispensable part of mechanism. The possible applications of cams are unlimited, and their shapes occur in great variety.

The transformation of one of the simple motions, such as rotation, into any other motions is often conveniently accomplished by means of a cam mechanism. It is a rotating or sliding piece in a mechanical linkage used especially in transforming rotary motion into linear motion or vice versa. A cam mechanism usually consists of two moving elements, the cam and the follower, mounted on a fixed frame. Cam devices are versatile, and almost any arbitrarily-specified motion can be obtained. In some instances, they offer the simplest and most compact way to transform motions. A common example is the camshaft of an automobile, which takes the rotary motion of the engine and translates it into the reciprocating motion necessary to operate the intake and exhaust valves of the cylinders.

A CAM has two parts,

► The FOLLOWER

► The CAM PROFILE.