Contents:
What Material is Spandex Fabric Made of?
What’s benifit of Spandex Fabric?
Is Spandex Fabric Natural or Synthetic?
What are the Advantages of Spandex Fabric?
Is Spandex Fabric Good Material?
How is Spandex Fabric made?
What is Spandex Fabric Used for?
How do Labs Test Spandex Fabric?
How do You Care for Spandex Fabric?
How do you Test the Elasticity of Spandex?
What is Spandex Fabric Used for?
What Material is Spandex Fabric Made of?
Spandex is the abbreviation of polyurethane fiber, which is a kind of elastic fiber. Spandex is generally composed of multiple filaments, generally 10D/root. Currently, there are 15D/root or even 20D/root. The less the number of theoretical roots, the better the evenness of the evenness, and the less the chance of overlapping forms. DMAC, the production solution of spinning, is harmful to human liver. Generally, 10D/root contains 0.5mg/kg, such as 15D/root contains 0.7mg/kg, which exceeds the standard. When producing spandex fabric, special attention must be paid to the winding tension, the number of counts on the tube, the breaking strength, the breaking elongation, the degree of forming, the amount of oil adhesion, the elastic recovery rate and so on. These problems directly affect the knitting, especially the knitting production. Pay more attention to single-sided fabrics.
What’s benifit of Spandex Fabric?
Spandex is a kind of elastic fiber, scientific name polyurethane fiber, abbreviated (PU). It is called “spandex” in mainland China. It is highly elastic and can be stretched 6 to 7 times, but it can quickly return to its original state with the loss of tension. Its molecular structure is a chain-like, soft and extensible Polyurethane enhances its properties by linking with hard segments. Elastic fibers are divided into two categories: one is polyester chains; the other is polyether chains. Polyester elastic fiber has strong anti-oxidation and oil resistance; polyether elastic fiber has good anti-mildew and detergent resistance.
What are the Advantages of Spandex?
Spandex has excellent elasticity. The strength is 2 to 3 times higher than latex yarn, the linear density is also finer, and it is more resistant to chemical degradation. Spandex has good acid and alkali resistance, sweat resistance, seawater resistance, dry cleaning resistance, and abrasion resistance.
Is Spandex Fabric Natural or Synthetic?
Spandex Fabric is a kind of sybthetic fiber fabric.Chemical fiber refers to those fibers that are processed by chemical methods using natural or synthetic high polymers as raw materials. It can be divided into two categories: man-made fibers and synthetic fibers. There are two kinds of man-made fibers, namely man-made cellulose fiber (such as viscose fiber, rich and strong fiber, etc.) and man-made protein fiber (such as soybean fiber, peanut fiber, etc.). The synthetic fiber camp is relatively large, with polyester fiber (ie polyester fiber). ), polyamide fiber (nylon 6, nylon 66, etc.), polyacrylonitrile fiber (acrylic), polyvinyl formal fiber (vinylon), polypropylene fiber (polypropylene), polyvinyl chloride fiber (chlorinated fiber), polyamino Formate fiber (spandex).
The composition material contains more than 85% polyurethane, and the trade names are Lycra (Lycra, the United States, the United Kingdom, the Netherlands, Canada, Brazil), Neolon (Neolon, Japan), Dorastan (Dorlastan, Germany) Wait. First, it was successfully researched by the German Bayer Company in 1937. The American DuPont Company began industrial production in 1959 and has now sold its spandex industry to the American Koch Industries Group, with a total production capacity of about 100,000 tons. The current global spandex production capacity is about 600,000 tons, while Hyosung’s spandex production capacity is close to 120,000 tons, becoming the world’s first. The first spandex enterprise in China was Yantai Spandex Factory, which started production in 1989. China’s current production capacity is about 350,000 tons, making it the world’s largest spandex producer.
There are two varieties of spandex, one is an inlaid copolymer of aromatic diisocyanate and hydroxyl-containing polyester segments (polyester spandex for short), and the other is inlaid with aromatic diisocyanate and hydroxyl-containing polyether segments. Copolymer (referred to as polyether spandex). Spandex fiber, elastic polyolefin fiber and elastic composite fiber are collectively referred to as elastic fiber.
Is Spandex Fabric Good Material?
Synthetic fiber with high elongation at break (over 400%), low modulus and high elastic recovery rate. The Chinese trade name of multi-block polyurethane fiber. Also known as elastic fiber. Spandex has high elongation (500%～700%), low elastic modulus (200% elongation, 0.04～0.12 g/denier) and high elastic recovery rate (200% elongation, 95%～99%). Except for higher strength, other physical and mechanical properties are very similar to those of natural latex yarn. It is more resistant to chemical degradation than latex yarn, has moderate thermal stability, and has a softening temperature above 200°C. Most dyes and finishing agents used for synthetic fibers and natural fibers are also suitable for dyeing and finishing of spandex. Spandex is resistant to sweat, seawater and various dry cleaning agents and most sunscreen oils. Long-term exposure to sunlight or chlorine bleach will also fade, but the degree of fade varies greatly with the type of spandex.
Spandex fiber has such high elasticity because its polymer chain is composed of low-melting, amorphous “soft” segments as the matrix and high-melting, crystalline “hard” segments embedded in it. The molecular chains of the flexible segment are cross-linked to form a certain network structure. Due to the small interaction force between the molecular chains, they can expand and contract freely, resulting in large elongation performance. The binding force of the molecular chain of the rigid segment is relatively large, and the molecular chain will not extend indefinitely, resulting in high resilience. The cross-section of radon filaments is mostly dog-bone-shaped, and some filaments have smooth or jagged surfaces. The breaking strength is the lowest among all textile fibers, only 0.44～0.88CN/dtex (the strength of the polyether type is higher than that of the polyester type).
The moisture absorption range is small, generally 0.3-1.2% (the moisture absorption rate of multifilament is slightly higher than that of monofilament). The heat resistance varies greatly depending on the variety. Most fibers are stored for a short time within the range of 90-150°C, and the fibers will not be damaged. The safe ironing temperature is below 150°C, which can be heated for interference and wet washing. It has good dyeing performance and can be dyed into various colors. The dye has a strong affinity for fibers. It can be adapted to most types of dyes. It has good chemical resistance and is resistant to most acids and alkalis, chemical agents, organic solvents, Dry cleaning agents and bleaching agents, as well as resistance to the sun and wind and snow, but not resistant to oxides, easy to make the fiber yellow and reduce the strength.
Spandex is generally not used alone, but is incorporated into the fabric in a small amount. This kind of fiber has both rubber properties and fiber properties. Most of it is used for core-spun yarns with spandex as the core yarn, called elastic core-spun yarn. The main characteristics of this kind of yarn are that it can obtain a good feel and appearance. The outer fiber composed of natural fiber has good moisture absorption; the second is that only 1-10% spandex filament can be used to produce high-quality stretch yarn; the third is the control range of the elasticity percentage from 10% to 20%, which can be based on the use of the product , Choose a different elasticity value. It is easy to spin 25-2500 denier yarns of different thicknesses, so it is widely used to make elastic knitted fabrics, such as socks, furniture covers, ski wear, sportswear, medical fabrics, belts, military equipment, elastic parts of space suits, etc. . As people put forward new requirements for fabrics, such as light weight, comfortable fit, soft texture, etc., the proportion of low-density spandex fabrics in synthetic fiber fabrics is also increasing. There are also spandex nude yarns and twisted yarns made by combining and twisting spandex and other fibers, which are mainly used for various warp knitting, weft knitted fabrics, woven fabrics and elastic fabrics.
How is Spandex Fabric made?
Spandex fiber overcomes the quality defects such as stress, strain performance, count range and rubber yarn modulus.
Dry spinning was the first to be used for production. Today, there are roughly four production methods:
Dry Spinning
DRY SPINNING, a method in which the solution is solidified into silk due to the volatilization of the solvent under a hot air stream.
Production process: solution—-spinning pump—-drying box, blowing hot air at 100℃ to volatilize the solution—-spinning—-winding and forming.
Spinning speed: from 200 to 800M/min.
Spinning temperature: 200～230℃.
Fiber fineness: 22.2～1244dtex.
Features: The process is polluted, the process is complicated, and the cost is high.
Melt spinning
MELT-SPINNING, a method in which high polymer is heated above the melting point to become a melt into filaments.
Production process: Polymerization without solvent-granulation-slicing at constant temperature-cleaning and impurity removal-drying-dehydration-into the screw press It is made into a solution-spinneret extrusion-cooling by a cold box-winding and forming.
Spinning speed: from 600 to 1600M/min.
Spinning temperature: 160～220℃.
Fiber fineness: 9～1100dtex.
Features: Short process, low cost, and low pollution.
Wet Spinning
WET-SPINNING, the method in which the original liquid is solidified into silk through double diffusion in the coagulation bath.
Production process: stock solution—-spinning pump—-enter warm water from the spinneret, below 90℃—-regeneration tank coagulation bath—-removal of solvent—-silk washing— -Drying—-winding and forming.
Spinning speed: from 50 to 150M/min.
Spinning temperature: warm water below 90°C.
Fiber fineness: 44～440dtex.
Features: The production process of this method has high pollution, slow spinning speed and high cost.
Chemical Reaction
A method in which high polymer is made into a solution through a chain extender to cause a chemical reaction to solidify into silk.
Production process: solution-through spinneret to coagulation liquid-adding chain extender-winding and forming-hardening-processing into net-like fibers.
Spinning speed: from 50 to 150M/min.
Fiber fineness: 44～80dtex.
Features: The production process of this method has high pollution and high cost.
What are the Different Types of Spandex?
1. There are also different brightness forms in the production of spandex, usually:
Transparent, CLEAR-LUSTER: The surface fiber is smoother, so the reflection becomes transparent, the friction rate is low, the evenness of the evenness is poor, and the coloring is poor. It is suitable for production of staple fiber materials and uses more warp fabrics.
White root, DULL-LUSTER: It is natural white, the surface fiber is more uneven, the friction surface is large, and the coloring effect is good. It is suitable for the production of long fibers and is used for thick roots, such as bust products and accessories.
Translucent, BRIGHT-LUSTER: Titanium dioxide and anti-slip agent are added to it, which has strong resistance to chemical agents. It is often used in swimming suits because of its anti-chlorine function.
Matte color, MATT-LUSTER: It is between natural white and translucent, matte white, suitable for knitting.
2. Spandex has different uses and various product forms, mainly divided into three types: bare yarn, core-spun yarn, covered or twisted yarn. Each different combination corresponds to a different purpose.
Bare yarn: It is 100% spandex yarn. Generally, bare yarn is not directly used on fabrics. Most of them are co-produced with rival materials and require special equipment for production. Knitwear is most commonly used, such as swimwear, sportswear, etc., generally 22-78Dtex.
Core spun yarn: yarn spun with naked yarn as the core and other materials as outer skin, referred to as CSY. For example, if the cotton core is used to insert the drafted bare yarn into the spinning car of the ring spinning machine, the elongation of the bare yarn of the wrapping core-spun yarn must be adjusted appropriately, and its expansion rate is suppressed to 2 to 3 times. Nowadays, core-spun yarn is divided into hard core yarn and soft core yarn. The opponent materials of core-spun yarn are cotton, polyester, nitrile and so on. It is widely used in fabrics, knitwear, bandages, socks, underwear, jeans, generally 22-235Dtex.
What is Spandex Blended with?
How is Cotton Spandex Blend?
60s cotton bale 22dtex = cotton 92% spandex 8%;
80s cotton bale 22dtex = cotton 90% spandex 10%;
55s cotton bale 33dtex = cotton 91% spandex 9%;
60s cotton bale 33dtex = cotton 90% spandex 10%;
30s cotton bale 44dtex = cotton 92% spandex 8%;
40s cotton bale 44dtex = cotton 90% spandex 10%;
50s cotton bale 44dtex = cotton 87% spandex 13%;
12s cotton bale 78dtex = cotton 96% spandex 4%;
16s cotton bale 78dtex = cotton 95% spandex 5%;
20s cotton bale 78dtex = cotton 93% spandex 7%;
30s cotton bale 78dtex = cotton 90% spandex 10%;
40s cotton bale 78dtex = cotton 87% spandex 13%;
50s cotton bale 78dtex = cotton 84% spandex 16%;
20s cotton bale 122dtex = cotton 93% spandex 7%;
36s cotton bale 122dtex = cotton 91% spandex 9%;
8s cotton bale 155dtex = cotton 95% spandex 5%;
20s cotton bale 155dtex = cotton 88% spandex 12%;
36s cotton bale 155dtex = cotton 79% spandex 21%;
40s cotton bale 155dtex = 77% cotton and 23% spandex.
Covered or twisted yarns: When weaving long fibers such as nylon and polyester, and weaving elastic fabrics, covered yarns are mostly used. The twisted yarns are made of naked yarns and twisted yarns, usually in order to increase the degree of covering of spandex. Two or three yarns can be twisted together. The one with one layer of the opponent’s yarn is called single-covered yarn, and the one with two layers is called double-covered yarn. The main use is 44-620Dtex, which is used for underwear and underwear accessories.
How is Cotton Spandex Blend?
56dtex nylon bag 78dtex = nylon 88% spandex 12%;
78dtex nylon bag 78dtex = nylon 92% spandex 8%;
78dtex nylon bag 33dtex = nylon 88% spandex 12%;
78dtex nylon bag 44dtex = nylon 63% spandex 14%;
78dtex nylon bag 78dtex = nylon 78% spandex 22%;
83dtex nylon bag 22dtex = nylon 92% spandex 8%;
83dtex nylon bag 33dtex = nylon 89% spandex 11%;
83dtex nylon bag 44dtex = nylon 86% spandex 14%;
83dtex nylon bag 78dtex = nylon 78% spandex 22%.
Special Fiber Mixing Rate
20s/2 cotton bale 44dtex = cotton 98% spandex 2%;
30s/2 cotton bale 44dtex = cotton 97% spandex 3%;
40s/2 cotton bale 44dtex = cotton 96% spandex 4%;
20s/2 cotton bale 78dtex = cotton 96% spandex 4%;
30s/2 cotton bale 78dtex = cotton 95% spandex 5%;
40s/2 cotton bale 78dtex = cotton 93% spandex 7%;
30s/2 polyester bag 44dtex = polyester 97% spandex 3%.
How do Labs Test Spandex Fabric
(1) PACKAGE DRAFT %: The tension of the elastic fiber on the roll is very important, and its tension should be kept even from the inside to the outside. If the tension is uneven, it will directly affect the effect of the woven fabric. The best roll tension is 8%-12%, and the tension error of each bobbin cannot exceed 3%.
(2) DTEX ON CHEESE: The number of threads on the tube is controlled by the winding tension, for example: 44dtex winding tension is 10%, that is, the actual number of threads on the tube is 40dtex, which is 10 thinner %. Nowadays, some spandex manufacturers believe that when the weight of spandex of each brand is the same, spandex with high rolling tension is undoubtedly longer in length, longer in weaving length, and lighter fabrics can be woven. At this point, you must pay attention to your own products. The requirements are selected.
(3) BREAKING TENACITY: Generally, each different brand or series of spandex has different strength performance. The test method can be tested in a conditioned environment with a 50mm strength machine, and the test is 100% (SS100), 200% (SS200), 300% (SS300), test five times each, generally observe the stability of 200% (SS200) data and other data. The greater the strength, the greater the elongation of the fabric, and the speed of knitting Hurry up.
(4) BREAKING ELONGATION): When measuring the breaking strength, the breaking elongation can be measured. Generally, the greater the elongation, the less the fabric content.
(5) FORMING DEGREE: According to the appearance test, if the forming is not good, the shape of each tube is different, and the size is different, which are all unqualified.
(6) OIL ADHESION: The best oil content of spandex is 5% (+/-2%). The more oil content or the longer the time, the outer layer of oil penetrates into the inner layer, and accumulates at the bottom of the cylinder, which affects the tension and weaving. The loss is large. The general oil component is silicone oil, containing stearic acid metal ions.
(7) ELASTIC RECOVERY RATE: general fiber elongation 100% or more, called elastic fiber, refers to the length increase under tension, and returns to the original length when released, and the difference between the original length and the recovered length is the elastic recovery rate , Generally 95% or more.
(8) Specific gravity: The specific gravity of spandex is 1.10.
(9) Conventional moisture regain: generally 1.3 (ASTM).
(10) Softening temperature: generally 190 degrees Celsius/390 degrees Fahrenheit.
(11) Melting temperature: generally 250 degrees Celsius/437 degrees Fahrenheit.
How do You Care for Spandex Fabric?
Spandex should be stored in an environment with constant temperature and humidity. The temperature is between 18-20 degrees Celsius. The lower the temperature, the longer the storage period. The relative humidity is 60%-70%. It should not be placed in a place exposed to sunlight. It is stored with chemical products such as sulfur dioxide and nitrogen oxides, causing it to decompose.
Storage period: 20D (3 months), 30D (4 months), 40D-70D (6 months), 100D-280D (9 months), thicker than 420D (12 months), the thicker the spandex, the storage period Longer.
When Spandex is knitted, from the constant temperature warehouse to the workshop, the carton is opened at least 16 hours in advance and placed in the weaving workshop to regain moisture to reduce yarn breakage during knitting.
Test Methods
Boiling water shrinkage test
(1) Take four spandex samples, remove the surface layer, and then take three sections of 10cm in length and mark the distance with a colored pen.
(2) Put the sample in boiling water (100°C) for 10 minutes, then take it out and hang it to dry at room temperature. After 5 minutes, measure its shrinkage length.
(3) Calculate the shrinkage rate of boiling water based on the difference between before and after boiling water, and the standard rate is 10-15%.
Boiling water shrinkage rate (%)=(10cm-test length)/10×100%
Conclusion: The boiling water shrinkage rate exceeds 10-15%, indicating that the stability of spandex is poor.
How do you Test the Elasticity of Spandex?
(1) Take four spandex samples, remove the surface layer, and then take three sections of 10cm in length, and mark the distance with a colored pen.
(2) Join the head and tail of the sample, test it on a single yarn strength machine, and stretch it at a speed of 50 cm/min.
(3) First stretch the sample by 100%, 150%, 200%, 250%, 300% for 3 times, and then calculate its tensile stress (cn) and elastic recovery rate for the fourth time. Elastic recovery rate%=(10cm-test length)/10 X 100%.
Conclusion: Different products have different requirements for elasticity of spandex. Some products require low elongation, high elasticity or high elongation, low elasticity or low elongation, low elasticity or high elongation and high elasticity for spandex, so different fabrics Kind to choose different suitable spandex. The standard rate is compared with other brands with 300% data to ensure that the quality of spandex used by the enterprise is consistent.
What is Spandex Fabric Used for?
Spandex can be used in garments that can be stretched to meet comfort requirements. Such as: professional sportswear, gym clothes and exercise clothing, diving suits, swimming suits, swimming suits for competitions, basketball suits, bras and suspenders, ski pants, disco, jeans, slacks, socks, leggings, diapers, tights, Belts, underwear, jumpsuits, spandex underwear, straps for male ballet dancers, surgical protective clothing, protective clothing for logistics forces, short sleeves for cycling, wrestling vests, boating suits, underwear, performance clothing, Qualitative clothing, etc. Such as: bras, furnishings, bead pillows.
The ratio of spandex used in general clothes is relatively small. In North America, it is seldom used on men’s clothes and more used on women’s clothes. Because women’s clothes are required to be more close-fitting. In use, other fibers such as cotton and polyester blends are added in large quantities to minimize the gloss.
