For many years, silk fabrics have been deeply loved by consumers. However, due to their high cost, easy wrinkles, easy fading, easy aging and yellowing, and difficulty in care, artificial silk fabrics have gradually attracted people’s attention.
What is imitation silk fabric?
The so-called imitation silk is essentially the use of physical or chemical methods to modify polyester fiber to make it similar to silk in appearance and wearing performance.
Products made of polyester as silk-like raw material, both in appearance and feel, are basically as fake as real ones. Polyester simulated silk products have the advantages of both natural and synthetic fibers. They are silk-style, light and elegant, soft and smooth, with soft luster and good drape. They are also comfortable and strong, wear-resistant, non-ironing, anti-wrinkle, washable and wearable. Silk fabric is good.
Since the 1960s, with the rapid development of synthetic fibers, the research and development of synthetic fiber-like silk came into being. Throughout the development of polyester simulated silk, it has gone through the following five important development stages:
The first generation (1962-1968)
Dedicated to imitating the appearance of silk. Products with special-shaped cross-section yarn, ordinary polyester yarn, strong twist and false twist processing technology and alkali reduction processing. The product has body, luster, smoothness and good iron-free properties and crepe resistance.
The second generation (1969-1973)
Dedicated to the thorough pursuit of silk style. The development of cationic dyeable polyester is the main symbol of the second generation of products. It makes polyester imitation silk products closer to silk products in fiber structure and style, and develops anti-static and anti-fouling products.
The third generation (1973-1978)
Dedicated to a deeper level of imitation of the appearance and beauty of silk. It focuses on physical modification and develops high multifilament, super multifilament and interlaced yarn products. Fine denier yarn and mixed fiber technology are the main signs of the third generation products. At the same time, polygonal and special-shaped cross-section yarns are developed to improve color development, color depth and brightness in dyeing and finishing technology. As a result, the fabric has a sheen like silk, feels soft and fluffy, and is not prone to pilling.
The fourth generation (1979-1984)
Dedicated to getting closer to the essence of silk. During this period, efforts were made to develop polyester filament ultra-fine denier, special-shaped, and mixed fiber technologies, and comprehensively applied a variety of technologies to give polyester filament a silky sound and luster like real silk, as well as good hygroscopicity and antifouling properties.
The fifth generation (since 1985)
Dedicated to “super real silk products” development. In addition to continuing to maintain the excellent silk-like style, the new generation of polyester simulated silk also focuses on “super”, that is, it is unique in a certain aspect, integrating the culmination of silk styles and each having its own characteristics.
After more than 50 years of history, imitation silk products have moved from simply imitating the luster, organizational structure and other appearance characteristics of real silk to imitating the comfort performance of real silk. “Super” situation. In addition to leveraging strengths and avoiding weaknesses, some can also add more new functions that meet human consumption needs based on the strong plasticity of chemical fibers, such as antibacterial properties, sun protection, and ceramic health care properties.
Silk fabric weaving technology
Ordinary polyester filament simulated silk technology
Mainly combined with weaving , through 15%~35% alkali reduction processing to improve the fiber feel and enhance the degree of simulation. Polyester fiber is hydrolyzed under the action of hot and strong alkali, causing the surface of the fiber to be eroded and cracked, the tissue is relaxed, the fiber becomes thinner, the weight is reduced, the interweaving resistance of the fabric is reduced, and the rigidity becomes smaller, resulting in a soft feel like natural silk. , soft luster and good drape properties.
After the polyester fiber is treated with alkali weight reduction, the fiber surface loses its original smoothness, and pitted marks appear. As the weight reduction rate increases, As the fiber increases, the width of the scar also increases, and even local cracks appear at some weak links inside the fiber, see the picture above. And when the alkali reduction rate reaches 15%~20%, obvious silk-like effect will be obtained.
Change the fiber cross-section
The cross-section of ordinary polyester filament is round, and the fabric formed is relatively smooth and has a waxy feel. It is easy to produce aurora, and the fabrics woven with it are quite different from silk fabrics.
The cross-section of silk is similar to a triangle, so it can play the role of a prism in contact with light, that is, it transmits part of the light and reflects part of the light at the same time, and has strong internal reflection and low light intensity. The surface reflects light, and this cross-section gives the silk fabric its unique, soft luster.
Today, the fiber cross-section has developed from triangle to polygon, Y-shape, H-shape Shapes and stars, etc., can be said to be endlessly varied, and hollow sections have also been introduced. These special-shaped yarns can eliminate aurora, make the luster soft, and improve the feel; at the same time, they can improve the moisture permeability, air permeability, stain resistance, etc. of the fabric. These properties make simulated silk The product can not only be close to silk products in appearance, but also be “miraculously” similar in terms of gloss, fluffiness, etc.
Fine-denier silk technology
The excellent drape, pearl-like luster and soft feel of silk fabrics largely come from the relatively fine fineness. Therefore, in the research of polyester simulated silk, fine denier is an important direction.
Produced using fine fibrillated filament raw materials, the layered structure of the filaments in the product is increased, thereby enhancing the light reflection ability inside the fiber, making the fiber fabric show a more delicate luster, and further imitating It improves the luster characteristics of silk products.
In addition, thanks to the high degree of fibrillation of the raw materials, the fineness of the single fibers in this type of imitation silk products is smaller , the feel of the fabric can be further improved, and this technology has also been widely used in actual production.
For example
Georgette crepe is finally made into simulated silk crepe through fine denier and strong twisting technology, combined with the subsequent alkali reduction process. The simulated silk products produced through this process have a soft feel, good drape, and are similar to Compared with imitation silk products produced from other raw materials, they show better wearing performance. The application of ultra-fine denier silk in the field of imitation silk products has greatly increased the application proportion of such products in the clothing field.
Strong twisting, false twisting, uneven thickness drawing and surface modification technology simulated silk
Improving polyester through processing technologies such as strong twisting and false twisting The dispersion, smoothness and roughness of the monofilament can consciously control the expansion rate, curl rate and shrinkage rate of the warp and weft yarns, thereby obtaining appearance effects such as fluffy, soft, elastic and crepe effects. Through uneven drafting, the The phenomenon of uneven thickness in the longitudinal direction of the monofilament makes the appearance style closer to natural silk, and the same distribution effect of fabric thickness is obtained. In addition, a more detailed simulation that highlights the microstructural characteristics of real silk is surface modification, which on the one hand obtains natural unevenness. On the other hand, the tiny cracks on the surface after treatment make the fiber surface have grooves close to the wavelength of light waves, which can obtain a deeper color and a good silky feel.
Composite yarn
Ordinary polyester filament has a single component, while composite yarn is composed of two or more types that are not mixed. Polymer composition. When selecting raw materials, production companies can make selections based on different needs.
Sheath-core structure composite yarn
This composite yarn is composed of two polymers with different components, one component is distributed in the fiber The center of the fiber forms the core, and another component is distributed in the cortex of the fiber to form a skin-core structure, usually with polyester as the core and nylon as the skin. Because nylon is in the skin layer, it has better hygroscopicity and dyeability. At the same time, because polyester with a higher elastic modulus serves as a supporting structure in the core layer, the woven fabric has better anti-wrinkle properties. If you want to weave a simulated silk fabric that is easy to dye and feels crisp, you can give priority to composite silk with a sheath-core structure.
Microporous composite yarn
Because polyester is a hydrophobic fiber, during the manufacturing process of imitation silk, the fabric has poor air permeability and Disadvantages include not absorbing sweat and poor wearing comfort. In order to solve this problem, people have developed a microporous composite fiber. The physical method of blending hollows and the chemical method of alkali reduction treatment are used to obtain a microporous structure, so that there are gaps inside the fiber. Through the internal and external penetration, The microporous structure improves the fiber’s water absorption. Therefore, when producing highly water-absorbent and hygroscopic imitation silk fabrics, many product developers will give priority to using microporous composite silk to achieve this function.
In the future, silk-like raw materials will develop in a diversified direction, and at the same time, they will be more closely matched with post-dyeing and finishing processes to achieve better silk-like effects. The cost of imitation silk fabric is low and the market development space is large.
