Slub was originally a kind of common defect in textile production. Due to the influence of some problems in the spinning process, such as drafting, uneven thickness, and so on, the yarn has uneven fineness locally, forming bulges similar to slub, producing slub defects, and affecting the quality of fabric.
However, when this kind of protrusion like bamboo is evenly distributed on the fabric surface, it can form a special art and science on the fabric surface, produce a unique fabric style, and meet people’s requirements for the diversification of fabric styles. Therefore, in the spinning process, it is considered that the yarn density changes regularly or irregularly in its length direction to obtain slub yarn, and this yarn is used in the production of fabric to form slub yarn fabric. With the different slubby parameters, slubby fabrics can form personalized literary and logical characteristics.
Slub yarn is characterized by the appearance of uneven thickness distribution. It is one of the most kinds of fancy yarn, including thick and thin slub yarn, pimple slub yarn, short fiber slub yarn, filament slub yarn, etc. Slub yarn can be used for light summer fabrics and heavy winter fabrics. It can be used for clothing fabric and decorative fabric. It has a prominent pattern, unique style, and strong three-dimensional sense.
The nominal number of slub yarn is generally named by the number of base yarn. For example, c14.5tex slub yarn means that the slub spacing is the number of normal yarn, and the number at the slub is larger. In actual production, when the front roller spins slub at variable speed, the high-speed value and twist value of the base yarn are generally set to spin the normal base yarn number, and then the low-speed value and other slub parameters are set to produce slub yarn.
At present, slub yarn is widely used in the production of various fabrics, which is in line with the current fashion trend. There are many kinds of slub yarn and a wide range of applications. Generally speaking, according to slub spinning form, there is airflow spinning slub and ring spinning slub; According to the length of bamboo knots: there are long bamboo, medium bamboo, and short bamboo; According to the multiple of bamboo knots: coarse bamboo, medium bamboo, and fine bamboo; wait.
Main parameters of slub yarn
Slub yarn parameters include base yarn density, slub thickness, slub length, and slub spacing
Due to the special structure of slub yarn, the cloth style is closely related to the above four parameters. Its various combinations determine its special style on the cloth. There are mainly four methods.
Because the slubby part of slubby yarn is thicker, the twist added to the slubby part during spinning is also less, and the fiber of slubby section is loose so that the dye absorption of the thick section and fine section is inconsistent during dyeing of slubby yarn, and then the style of raindrop or rain silk will be formed according to the length of slubby yarn.
The styles formed by different raw materials are different: for example, the slub yarn fabric made of single yarn spun with ordinary cotton and polyester raw materials has obvious slub; The use of special-shaped fibers such as cationic polyester, bright polyester, viscose, and so on to form a finer slub, and then twisted with ordinary yarn to form a line, which can be made into high-grade fabrics.
48.6 ~ 58.3tex (nel2 ~ 10) slub yarn is spun on a rotor spinning frame, and its slub can be 1.3 ~ 1.8 times higher than that of normal yarn. With the change of slub spacing and length, high-grade fabrics with hemp style can be woven.
By using slub yarn with different length, thickness, pitch and raw materials, rich and colorful varieties with different styles can be developed to meet the needs of various consumers.
Yarn types and styles of different slub yarn devices
The style and type of slub yarn produced by different slub yarn devices are different. With the continuous improvement of the technical level of slub yarn devices, the design and color types of slub yarn are also increasing. From the drive system of slub spinning device, from the earliest clutch type and stepping motor to the current servo motor; In terms of the variable speed system of the slub spinning device, there are more and more designs and colors of slubs spun by changing the front roller speed, and also by changing the rear roller and front roller speed.
For example, the slubby yarn device of the front roller speed change system driven by the stepping motor generally spins five slubby yarns with different pitch and pitch lengths as a small cycle, and 25 slubby yarns are formed as a large cycle, while the slubby yarn device driven by the servo motor can set the slubby yarn length and pitch arbitrarily, and the slubby yarn thickness can be changed arbitrarily at different magnification on the same yarn, The slub steepness can be trimmed arbitrarily, the slub shape is diverse, and the slub control accuracy can reach 0.1mm. It can spin slub yarn with regular, irregular, slub on slub, multi-level fuzzy slub, random and nonrepeated spinning, and the effect is very good.
Therefore, when selecting a slub yarn device, it is necessary to select the appropriate slub yarn device according to the different design and color types of slub fabric. The functional characteristics of various slub yarn devices are very different. In terms of expanding the variety of designs and colors, the front, middle and rear roller speed change system driven by servo motor should be selected. The spun slubs do not deform and will not form regularly arranged spots on the cloth slubs, which are referred to as “regular spots”. At the same time, the slub yarn CAD simulation software is attached to display the effect map of weft slub position distribution on the cloth, Ensure that the cloth style is beautiful, avoid the impact of multiple proofing on the delivery date, and the efficiency will be greatly improved.
Basic yarn number and comprehensive yarn number of slub yarn
The nominal number of slub yarn is generally named by the number of base yarn. For example, c14.5tex slub yarn refers to the number of normal yarn when the slub spacing is asked, and the number at the slub is larger. In actual production, when the front roller spins slub at variable speed, the high-speed value and twist value of the base yarn are generally set to spin the normal base yarn number, and then the low-speed value and other slub parameters are set to produce slub yarn.
The comprehensive number of slubby yarn refers to the comprehensive number of base yarn and slubby yarn. There are differences between the general process design and the actual spinning comprehensive number, and the differences in the comprehensive number of slubby yarn spun by different types of slubby yarn devices are also different. The comprehensive number is an important basis for daily control of spinning weight deviation in production, and it is also the main index of cotton cost accounting for slub yarn. When spinning slub yarn, some enterprises use the base yarn number to control the yarn weight deviation, so that the actual base yarn number is lighter and more meters of cloth can be woven. This is acceptable for slub yarn with thin slub, but for slub yarn with thick and dense slub, the base yarn will be too thin and cause many post-processing broken ends.
Design comprehensive number refers to the comprehensive number of slub yarn in process design. It is the weighted average of the number of base yarn and slub yarn corresponding to the percentage of pitch and slub length in a certain cycle and its length in a certain cycle.
It should be pointed out that the total yarn length of a certain cycle should be calculated according to the law of slub arrangement.
For regular, it is the cycle length in a cycle. For example, when five bamboo knots are in a small cycle, the total length of five bamboo knots can be the total length of a cycle; For irregular, it can be estimated according to the set average pitch, pitch, and coarseness multiple.
The actual comprehensive number is the number of slub yarn actually spun, which is different from the comprehensive number of process designs. Therefore, in daily production, the actual comprehensive number of finished yarn shall be controlled to reach or close to the comprehensive number of process designs according to the provisions of national yarn standards, and its weight deviation, batch deviation, and monthly deviation shall be controlled to ± 2.5% and ± 0.5%.