Yarn is a thin and long product made by the first twisting of fibers or filaments, which has tensile strength and softness. Strands are made of two or more yarns combined and twisted for the second time, and their fineness, strength and uniformity are higher than those of yarn. Strong is a product made of strands and all twisted for the third time. There are many varieties of yarn, and the hair method is also different, and this article is divided according to its structural characteristics.
(1)Staple fiber yarn
Cotton, wool and other fibers are twisted back to form a yarn called staple fiber yarn, and its structure is complex and slightly different due to different spinning and twisting methods. Generally speaking, the center of the yarn is a yarn core composed of dense fibers, and on the surface of the yarn, there is a fluff area formed by the fiber head exposed. The structure of a untwisted staple yarn indicates that there are more and more complex connections between the surfaces of the core layers than the filament yarn. There are also many knots within the low-quality staple fiber yarn. Due to the random arrangement of the fibers, together with the variation in twist and fineness, the coarse details in the direction of the yarn length are generated. With the different addition methods, the quality and uniformity of staple fiber yarn are still very different. The staple fiber yarn has a bulky structure, a full appearance, good thermal insulation and comfort, mainly due to the air contained in the voids in the yarn.
(2)Filament yarn
Silk or chemical fiber monofilament multiple combined, plus a small amount of twisting back to form filament yarn. Smooth filament yarn (undeformed processing) is uniform, shiny and has good strength. Chemical fiber filament yarn is used as a raw material for clothing, which is characterized by smooth fabric, color, easy to wash and dry quickly, but lacks the warmth and comfort of natural fiber fabrics, and the single fiber filament yarn is often thicker and is used for fishing nets and bags.
(3)Bulky yarn
The bulky yarn itself is a staple fiber yarn or filament yarn, but it has a larger performance volume than the original yarn, and it is bulky and soft. It includes the following three types.
1.Expanded yarn Nitrile yarn fiber thermoplasticity, in the case of heating and stretching, it will produce a large elongation, and then cool and fix to form a high shrinkage fiber. This fiber and ordinary fiber are blended to make staple fiber yarn, after steam processing, the high shrinkage fiber produces longitudinal shrinkage and gathers in the yarn core, and the ordinary fiber forms a curl or ring and bulges, so that the yarn structure becomes bulky, and the volume increases, which is the bulky yarn.
2.Textured yarn is a filament yarn that has been deformed. In the production process, some methods are applied to make the silk fibers produce permanent curls, loops and wrinkles, so that the gaps between the fibers are increased and the yarn body is bulky. Therefore, textured yarn has the important properties of staple fiber yarn----- which is both warm and breathable.
3.Stretch yarn Stretch yarn has a high degree of elongation (3---5 times) and resilience. When it is fully extended, it behaves like a normal filament yarn, and when it is sufficiently relaxed, it resembles a bulking yarn. The vast majority of stretch yarns are made from thermoplastic filaments (nylon), which are false-twisted and heat-set to produce permanent curls, but without entanglement between the roots. Knitted underwear made from it has a snug feel.
(4)Fancy yarn (thread)
Fancy yarn has a fancy appearance for decoration, and there are many varieties and production methods. The structure of fancy yarn is composed of core yarn, decorative yarn and fixed yarn. The core yarn bears the strength and is the main yarn, the decorative yarn is wrapped on the core yarn to form an effect, and the fixed yarn is wrapped around the outer circumference of the decorative yarn in the opposite twist direction to fix the pattern, but there are also cases where the fixed yarn is not used.
(5)Composite yarn (thread)
The composite yarn (thread) is uniform on the outside and is composed of yarns of different components. There are two types of this:
1.Core spun yarn Its central yarn is covered by fibers or another yarn. For example, the elastic thread has a rubber band in the center, and its periphery is wrapped in yarn. Another example is polyester-cotton yarn, which is wrapped in polyester filament with high quality, the cotton shell makes the yarn sewable, and the polyester core makes the yarn strong.
2.Wrapping yarn is wrapped with filament around the periphery of the untwisted fiber bundle (staple fiber or filament).