The start-up of the Circular Knitting Machine will leave a mark in the weft direction of the woven fabric. This type of trace differs depending on the type of fabric, the condition of the loom, etc. Generally, there will be a fine line of indentation, and the line of weaving between the weaving machine and the machine before and after the machine stops will be obvious; sometimes there will be wider traces and the loom. The difference between woven fabrics before and after the shutdown is not very obvious.
After the fabric is dyed, there is a certain color difference between the position with the mark of the stop mark and the normal production of the fabric without shutdown. If the marks of the occurrence of the stop mark occur frequently and the degree is serious, the normal cutting and use of the fabric will be affected and waste will be formed.
Causes of stop marks
There are many reasons for the creation of a stop mark:
1. The abrupt change in the amount of yarn to be fed causes the yarn tension to be uneven, thereby changing the shape and size of the coil to form a stop mark;
2. The relative swing between the transmission Gear and the main shaft will cause the drive gear positioning groove and the drive shaft positioning pin to wear. In severe cases, the gear shaft will be worn and become larger, which will affect the yarn tension caused by the stop mark;
3. The relative slippage between the yarn feeding amount adjusting disc and the yarn storage device's driving belt. As the yarn feeding quantity regulates the wear of the rubber particles in the disc and the storage belt, or the pressure between the transmission belt and the rubber particles is insufficient, the loom during the shutdown and start-up process. The rapid change of the running speed causes the friction coefficient between the rubber particles and the conveyor belt to become smaller, resulting in relative slipping, resulting in a change in the number of yarns per unit rotation, and further affecting the yarn tension to form a running mark.
4. The abrasion of the gear teeth of the accumulator or the filling of the batt and the wear of the conveyor belt cause the relative slippage of the yarn accumulator and the conveyor during the stoppage and start-up of the loom, resulting in a reduction in the number of yarns per unit of yarn traverse or Increase to form a stop mark.
In this case, the width of the stop mark is wider, which is also caused by the change in the length of the coil. The coil length generally varies by 2% to 8%. The other relevant transmission belts in the yarn feeding system are too loose, and the wear will also cause the non-uniform tension to form a stop mark when the machine stops and starts.
Ways to improve the track
In general, the methods for improving the stop marks include extending the deceleration time of the loom, increasing the billet force, reducing the virtual position of the uprising lever of the tribrach, and the selection of the model.
The longer the loom is in the process of deceleration, the smaller the swing rate of change between the gears and the relative sliding change rate of the belt, so that the tension of the yarn is not changed too quickly and the degree of the stop mark is reduced. The longer the braking time, the longer the loom will continue to run after the yarn break. Due to the limitation of yarn storage capacity, the general braking time is set to 1.5 seconds to 1.8 seconds, so as to ensure that the yarn will not cause rot. .
The improvement of the stop mark can also be achieved by reducing the imaginary position of the riser of the delta chassis. That is, the meshing clearance between the gears and the relative swing gears between the gears and the shafts is reduced, and the virtual position between the needles and the triangles is reduced (leaf bed virtual position). In order to ensure the normal operation of the loom, the virtual position of the leaf bed can generally be controlled at about 0.1 mm.
At present, most machine-type syringe triangular bases use a central lifting device, and the virtual support positions of each rising point support rod are large, and even when the Knitting Needle rotates rapidly, the triangle seat is thrown to cause a tension change. Properly reducing the virtual position of the support rod not only ensures normal use of the central lift, but also does not cause the triangular seat to be thrown too severely. When the loom rotates normally, the throwing volume on the triangular plate is generally controlled within 0.03 mm.
Most of today's circular knitting machines use wear plates to replace the design of steel wire racetracks. After the normal use of the wire ball type bead round machine for 3 to 5 years due to the wear of the bead and the steel wire runway, the loom drifts severely during the acceleration and deceleration operation, thereby increasing the severity of the stop mark. Therefore, when choosing a model, production companies should try to avoid selecting enough models, and they should choose a model with good precision and well-designed design.
Reading extension:
Knitting circular knitting machine , scientific name is knitted circular weft knitting machine (or circular knitting machine). Because it has many coiling systems, high rotation speed, high output, rapid flower shape change, good fabric quality, few processes, and strong product adaptability, it has developed rapidly.
The knitting circular knitting machine is divided into two types according to the types of fabrics it produces. There are two kinds of single-sided knitting circular knitting machines and double-sided knitting circular knitting machines. The single-sided series of knitting circular knitting machines can be divided into several types, such as ordinary single-side knitting circular knitting machines, single-sided circular knitting machines, three-line weft insertion machines, and jacquard single-side knitting circular knitting machines.
Ordinary single-knit circular knitting machine has a large number of turns, high rotation speed, and high output. Ordinary single-knit circular knitting machines have single-track (one runway), two-needle, three-needle, four-needle, and six-needle machines. Most of the knitting machines currently use a four-needle single-sided circular knitting machine. It is the use of knitting needles and triangle organic combination to weave a variety of new fabrics.
One-sided terry machine is also called single towel machine. It has a single-needle, double-needle, four-needle, four-needle machine model, and has a positive terry looper and a reverse terry looper. It uses the arrangement of sinkers and yarns to weave a new type of fabric.
The three-wire weft insertion machine is called a sweater machine or a fleece machine in the knitting enterprise. It has single-needle, double-needle, and four-needle models that are used to produce various types of pull-pile and pull-free fleece products. It is the use of knitting needles and arranged yarns to produce new fabrics.
The double-knit circular knitting machine is a circular knitting machine with two syringes, namely an upper cylinder (commonly known as a dial plate) and a lower cylinder. The dial plate and the cylinder are arranged at 90 degrees vertically. It mainly includes the following types: rib machine, ordinary double-sided circular knitting machine, jacquard double-knit circular knitting machine.
Ribbing machine is a special model of double-sided circular knitting machine. It has 11 needle tracks (a needle track in the dial, a needle track in the barrel), (2 2) needle tracks, (2 4) needle tracks, and (4 4) needle tracks.
Ordinary double-sided circular knitting machine, also known as cotton wool machine, multi-function machine, universal knitting machine, etc., it has 11 needle path (a needle path of the dial, a needle path of the Needle Cylinder), (2 2) needle path, (2 4) Needle track and (4 4) needle track. At present, companies that have newly introduced knitting circular knitting machines generally produce more varieties of flowers. Most of the imported equipment is mainly (24) needle-and-ball knitting machines. It uses the mutual arrangement of triangles and knitting needles and yarn arrangement. Weaving to produce new knitted fabrics.
The double-sided jacquard knitting circular knitting machine has two types, a small jacquard machine and a large jacquard machine. Among them, the small jacquard knitting circular knitting machine is referred to as a mechanical jacquard machine in the knitting enterprise. It has the advantages of simple, convenient, and quick change of variety, and its disadvantage is that it has low rotation speed and low output.
The large-scale double-sided jacquard knitting circular knitting machine is commonly known as the computerized jacquard circular knitting machine, because it is the design and production of a good floppy disk inserted into the computer, the input program can be weaving production, it is also known as the fool big circle machine.
The computerized jacquard knitting circular knitting machine has greatly shortened the product design cycle. Its product cost is lower, and the product quality is greatly improved. The economic and social benefits of the enterprise can be significantly improved, and at the same time, the competitiveness and resilience of the enterprise can also be improved.
