Viscose rayon, cuprammonium rayon (cupro), high wet-modulus rayon (Modal), and lyocell and their care … Acetate and triacetate and their care … Nylon (polyamide) and its care … Polyester and its care … PLA and its care … Acrylic and modacrylic and their care … Spandex (Elastane) and its care … Polypropylene and its care; lastol … Microfibers … Blends … Caring for hydrophobic synthetic fibers
Man-made or manufactured fibers have been used to make fabric for more than a century. Rayon, invented in the late nineteenth century, was first commercially produced in this country in 1910; acetate was commercially produced by the 1920s. Both of these are based on plant, or cellulosic, fibers. When nylon was introduced, with great fanfare, in 1939, it was the first fiber made entirely from synthesized or manufactured chemicals. Many other entirely synthetic fibers followed in short order. By 1960, acrylic and modacrylic, olefin, polyester, and spandex fibers were all well known, and fabrics composed of innumerable blends of two or more synthetics or of synthetics and natural fibers became popular. These new fibers constituted a revolution.
Man-made fibers other than rayon and acetate—the synthetics—are unabsorbent and hydrophobic. (Rayon and acetate fibers are based on cellulose and are therefore absorbent.) The synthetics are also thermoplastic—that is, they melt or soften when enough heat is applied and harden when they are cooled. As a result, creases or smoothness can be programmed into the cloth by a process called heat setting. If the cloth is smoothed when hot enough, it stays smooth unless it is rendered that hot once more. Thus such cloth needs little or no ironing. Similarly, if a fabric made of synthetic fibers is creased when at the right temperature, it will stay creased unless it is once more brought to that temperature. Care labels on clothes made of synthetic fibers often call for low to moderate temperatures in washing and drying and a cool-down period in the dryer; this is to avoid setting in wrinkles. Likewise, these fabrics should be ironed at low to medium settings.
Rayon
Rayon is made of regenerated cellulose derived from cotton fiber or wood pulp. The variety of rayons on the market makes it difficult to generalize about its properties. Not only are there different types of rayon, but each type can be produced in both thrown or filament yarn and spun yarn, and the characteristics of these spun and filament yarns may be markedly different. Rayon filament yarns produce silklike fabrics. Spun rayon can be napped, finished, and constructed to resemble fabrics of cotton, linen, and wool. (Such rayon fabrics, however, will function quite differently from the fabrics of natural fibers that they resemble.) Rayon fibers can be effectively blended with many other fibers, natural and synthetic.
Viscose Rayon. Most of the rayon you buy is viscose rayon. Its name derives from a step in its processing in which a cellulose mixture is transformed into a viscous solution. This type of rayon is usually identified on the fiber content label merely as “rayon” or, often, “viscose.”
Fabric made from viscose rayon is usually soft and drapable with a pleasant cottony hand. It is weaker than silk, linen, cotton, and wool. It is highly absorbent—even more than cotton or linen—and cool, characteristics that make it one of the most comfortable of fibers, especially in warm weather. Viscose rayon fabric may stretch when it gets wet and shrink as it dries, and may even stretch and shrink with changes in atmospheric humidity; thus it is usually a poor choice for draperies. Unlike cotton and linen, rayon fabrics lose much strength when wet, so laundering may not be recommended or may have to be done with gentle agitation. Unless given a shrink-resistant treatment, viscose rayon fabrics tend to shrink more than comparable cotton fabrics. Viscose rayon fiber is modestly more elastic than cotton or linen but less elastic than silk and wool. Rayon fabric tends to be rather limp or lacking in body.
Viscose rayon fabric tends to lack the resilience of silk and wool and therefore wrinkles readily. Its inherent tendency to wrinkle is one of its biggest disadvantages, but this may be reduced by wrinkle-resistance treatments and by careful engineering of the construction of the yarn and fabric. When buying an item made of rayon fabric, crumple it for a few seconds in your hand and then release it to determine how much it wrinkles.
Prolonged exposure to sunlight may cause weakening or yellowing of viscose rayon fibers and fabrics. Viscose rayon fabric mildews if left damp. It is vulnerable to silverfish but not to moths. Like all cellulosic fibers, viscose rayon fiber is vulnerable to acids but has good resistance to alkalies.
Cuprammonium Rayon. Cuprammonium rayon, also known as cupro, Bemberg, or cupra rayon, is named after a step in its processing in which cellulose is dissolved in a Cuprammonium hydroxide solution. The buyer may be told only that it is “rayon.” Cuprammonium rayon is soft, lustrous, and silky, and usually it is produced as filament rayon. Fabrics made from cuprammonium rayon tend to be more resilient than viscose rayon—that is, they do not wrinkle so easily. Cuprammonium rayon fabrics also tend to have greater abrasion resistance than viscose rayon. Thus they make excellent linings as well as women’s dresses and blouses.
Modal (High Wet-Modulus Rayons). Rayon fibers have been developed which have greatly increased strength when wet, comparable to that of cotton; they can be mercerized and rendered shrink-resistant with compressive shrinkage treatments. These fibers are known as Modal (or high wet-modulus rayon, modified rayons, high-performance, or polynosic rayons). Fabrics made from Modal often look and feel like high-quality cotton fabrics and tend to have more body and stiffness than viscose rayon fabrics, but they can also be silky or woolly. Because they have better wet strength, these types of rayon are more readily launderable than viscose rayon and can usually be machine-washed (subject, of course, to the usual caveats). Acid perspiration will cause some types of high wet-modulus rayon to deteriorate.
Caring for Rayon Fabrics. The buyer of clothes or furnishings made of rayon fabrics should be sure to check care labels before purchasing. Many inexpensive pieces of rayon sportswear may require the inconvenience of hand-washing or the expense of dry cleaning. High wet-modulus rayons, however, are usually machine-washable.
Many, but not all, types of viscose rayon have a smooth surface that sheds dirt readily. Theoretically, viscose rayon may be both dry-cleaned and laundered. For many reasons, however, dry cleaning is more frequently recommended. Viscose rayon fabrics weaken greatly when wet and often shrink, bleed colors, go limp, and wrinkle badly after washing. Laundering more quickly wears them out. Viscose rayon fabrics are frequently given water-soluble finishes and sizings that may dissolve in laundering, resulting in changes for the worse in the fabrics’ hand and drape.
Launderable viscose rayon should be handled very gently during laundering. It is more vulnerable to all sorts of chemicals than cotton, including alkaline laundry solutions. It should usually be hand-washed in mild detergent and warm water, then squeezed—not wrung or twisted—to remove excess water, unless the garment care label explicitly permits machine-washing. When it does, it usually calls for using a shorter, delicate agitation cycle. Viscose rayon knits should be dried flat; woven viscose rayon fabrics should be hung to dry. White viscose rayon will ordinarily not turn gray or yellow with cleaning or laundering and therefore usually needs no bleaching, but household bleaches may be used, with care, on white viscose rayon, so long as it is not blended with another fiber that cannot be bleached. Some types of rayon are much sturdier than regular viscose rayon, so do not hesitate to take advantage of vigorous laundering methods when you find them prescribed on a rayon fabric care label.
Viscose rayon fabrics should usually be ironed damp with a low to medium iron or with a steam iron. Some rayon fabrics develop a shine from ironing, so use a press cloth or iron the fabric on the wrong side. (See chapter 6, “Ironing.”)
Lyocell (Tencel)
Lyocell is the generic name of a new (FTC approved in 1996) rayonlike, cellulosic fiber that is more wrinkle-resistant, shrink-resistant, durable, and strong than viscose rayon. It is absorbent, with an appealing soft, luxurious hand. Like rayon, it is derived from wood pulp, but it is produced through an environmentally more favorable process. It tends to be more expensive than viscose rayon. Lyocell is used both alone and in blends with linen, cotton, rayon, and wool fibers. Lyocell fabrics are noted for their comfort.
Lyocell may be treated with antiwrinkling resins. Although this treatment weakens the fabric, it also reduces wrinkling, shrinking, and fuzzing. Lyocell burns like rayon.
Follow the care label on garments made of Lyocell; the care procedures called for may be necessary to protect finishes on the fabric, and you may otherwise get excessive shrinking or wrinkling. Lyocell may shrink slightly in laundering but it does not “exhibit the progressive shrinking of rayon fabrics.” Lyocell fabrics should be washed on the gentle cycle or dry-cleaned. Gentle washing decreases “the chance of causing uneven color, fuzziness, pilling, and unacceptable hand.” Lyocell weakens when wet. Lyocell fibers can be bleached with chlorine or oxygen bleaches.
Acetate and Triacetate
Properties of Acetate and Triacetate. Acetate, or cellulose acetate, is made in a process that begins by treating cellulose, derived from wood, with acetic acid. Acetate fabrics are often lovely. They are smooth, very lustrous, and silk-like in appearance and hand. Triacetate, acetate’s chemical cousin, is more versatile and may be constructed into fabrics that resemble those made of rayon, cotton, wool, or silk fibers. Both acetate and triacetate fabrics drape attractively. They tend to be more expensive than those made of cotton, rayon, or polyester.
Acetate and triacetate, however, are both weak fibers, and fabrics made of them have poor abrasion resistance. Acetate fabrics become significantly weaker when wet, which means that they must usually be dry-cleaned; when launderable, acetate fabrics must be washed with great care. Triacetate is less weakened by wetness and can usually be machine-washed and -dried. Fabrics made from acetate and triacetate are more elastic, warmer, and more wrinkle-resistant than rayon; they also shrink less. Triacetate is quite wrinkle-resistant—more so than acetate—and when wrinkles do form in a triacetate garment they tend to fall out when it is hung for a while.
Acetate and triacetate have a little absorbency, but much less than fibers classified as hydrophilic. Both are classified as hydrophobic, and fabrics made of them may feel uncomfortable in hot, humid weather. They are useful in items such as raincoats or shower curtains that need some water resistance. Both are used in dresses, blouses, and other clothes, as well as draperies and curtains, but not in articles that will receive hard wear. Although linings are often made of acetate, its weakness and poor abrasion resistance mean that otherwise durable coats with acetate linings will need new linings long before the rest of the coat wears out. Acetate’s low absorbency can interfere with the comfort of summer garments lined with it.
Both acetate and triacetate are thermoplastic, triacetate more so than acetate. Triacetate can receive permanent heat-set pleats and creases; acetate cannot. Triacetate can take much more heat than acetate before melting. Acetate will melt and stick to a hot iron, but triacetate melts at a higher temperature than irons reach.
Both acetate and triacetate have good pill resistance. They do not mildew and will not be attacked by pests (except that silverfish might harm the cloth in the process of devouring any starch in it). Both fibers, but triacetate more than acetate, tend to build up static unless they have received antistatic treatments. Acetate and triacetate have moderate resistance to the ultraviolet radiation in sunlight. Concentrated solutions of alkalies or acids will harm them. Acetate and triacetate and their blends will be destroyed by nail-polish remover, paint remover, and other solvents that contain acetone.
Special acetate dyes are used on acetate, and they may bleed, fade in laundering or in contact with atmospheric gases (a phenomenon known as “fume fading”), or discolor with perspiration. Solution dyeing solves these problems; the color of solution-dyed acetate is fast to washing, atmospheric gases, perspiration, and light. Triacetate is less likely to be discolored or weakened by perspiration and is less prone to fume fading and fading during washing than acetate.
Caring for Acetate and Triacetate. Dry cleaning is usually recommended for acetate fabrics because acetate fibers are fragile, lose strength when wet, and are highly temperature-sensitive. Triacetate, however, is usually machine-washable. When acetate is launderable, either gentle machine-washing or hand-laundering will be recommended. Lukewarm water, not hot, is usually recommended—or acetate fabric will shrink and wrinkle—and mild soaps or detergents. Bleaches will not ordinarily be necessary on white acetate because it tends to stay white, but if there are stains, household bleaches may be used cautiously. Bleaches may also be useful on white fabrics that are blends of acetate with other fibers that do not stay white. Colored acetate fabrics should not be soaked because they will bleed. (Solution-dyed acetate, however, will have color that is fast to laundering.) If you hand-wash acetate or triacetate fabrics, do not wring, twist, or rub them. You may wish to use a fabric softener now and then.
Roll acetate items in a towel. Dry knits flat and hang wovens to dry, unless the care instructions permit machine-drying. Usually you can tumble dry triacetate; use the permanent-press cycle (at medium to low temperatures) to take advantage of the cool-down period, and remove the items promptly. If either of these fabrics is left to sit warm in a dryer, it will wrinkle. Triacetate will need little to no ironing, but it can take a hot iron. (It may be billed as wash and wear.) Acetate fabric will need damp ironing on its wrong (back) side at low to medium temperatures, or on the right side using a press cloth.
Nylon (Polyamide)
On May 15, 1940, in a remarkable marketing event, nylon hose were offered for sale throughout the United States following an extraordinary advertising campaign addressed to a public already disposed to admire rather than disdain man-made fibers. It is difficult for us today to imagine how a mere article of clothing could cause such a stir in the world, or how eager women were to get rid of silk hose that ran, sagged, and bagged.
The word “nylon” refers to any member of a group of similar compounds (polymers) called polyamides. These polymers are made from coal, petroleum, air, water, and sometimes cereal waste products such as oat hulls or corncobs. On the fiber content labels of goods produced outside the United States, nylon is often called “polyamide.”
Properties of Nylon. Nylon fiber comes in many chemical forms that are sold under a variety of trade names and differ greatly in their properties. Spun and filament yarn nylons also differ significantly from each other. However, the various types of nylon fiber share some common characteristics. Nylon fibers are light and strong and highly resistant to abrasion. They are also extremely elastic—second only to spandex and rubber. Such qualities make nylon fibers exceptionally well suited for use in hosiery and sheer fabrics. Nylon fibers are also resilient, so nylon fabrics resist wrinkling, and wrinkles that develop during use or wear fall out easily. In looks and hand, fabrics made of nylon often have a silky luster, but nylon fabrics can easily resemble those made of cotton, wool, or other fibers in their appearance and hand.
Nylon can be made into warm fabrics. It is low in absorbency (although it is more absorbent than other hydrophobic fibers such as polyester, polypropylene, or acrylic), and nylon fabrics can feel hot and sticky in warm, humid weather. A tightly woven, light, filament nylon, which is impermeable to air, heat, or moisture, makes an excellent windbreaker or raincoat, but it may trap moisture inside and make you feel cold and clammy in winter or hot and sticky in summer. Spun nylon, used in sweaters and socks, is warmer than filament nylon because its fuzziness traps additional heat. And because nylon can be rendered into exceptionally fine, sheer, and light fabrics that air readily penetrates, it is also used for summer wear.
Newer types of nylon fabrics and new treatments applied to nylon (and other synthetics) have been developed to solve some of nylon’s problems with moisture and comfort. There are now a few types of nylon that wick moisture quite effectively. Fabrics made from nylon microfibers may be waterproof yet breathable, with a pleasant hand. Such fabrics therefore have a different comfort profile from those made of older types of nylons.
Nylon is not damaged by mildew, moths, or other pests. It is much weakened by exposure to sunlight, but neither sunlight nor laundering causes dyes used on nylon fabrics to fade. Perspiration can discolor it. Many types of nylon tend to have annoying problems with pilling and static buildup. Modifications of nylon fiber that render it static-resistant, however, are available.
Nylon’s resilience, elasticity, and spectacular strength are relied on in a variety of highly desirable blends with both natural and synthetic fibers.
Caring for Nylon Fabrics. Care labels usually recommend laundering nylon, although in principle it is dry-cleanable. But nylon is somewhat difficult to launder well. As a hydrophobic fiber, it holds oily soils and stains rather tenaciously but at the same time needs gentle treatment. To avoid a buildup of oily soil or odor, follow the methods recommended on pages 369-70, “A Note on Caring for Synthetic (Hydrophobic) Fibers”: frequent washing, pre-treating, presoaking, plenty of detergent, warm water, and so on. Being static-prone, nylon attracts dirt and lint. It also tends to take up dirt from the wash water when it is laundered. You can use ordinary soap or detergent to launder nylon. Always wash white nylon separately from any colored fabrics, no matter how pale, because of the strong propensity of white nylon to pick up any hint of color and turn dingy. Once this happens, you will probably not be able to remove the dinginess. Bleaching is usually unnecessary. If you feel you need to use a bleach, you might try an oxygen bleach. Do not use chlorine bleach; it tends to yellow nylon. If nylon yellows from other causes or from unknown causes, you have nothing to lose by trying the remedy suggested in “Yellowing of White Nylon,” page 168.
When laundering, use gentle (slow) agitation and a slow spin (or a brief spin, if you have no choice of spin speed), with warm wash water and a cool-down rinse. Thorough rinsing is advisable. Set the dryer at low temperature using the permanent-press cycle, which has a cool-down period, and remove promptly when dry to avoid setting in wrinkles. (Nylon is thermoplastic.) Iron at a low to medium setting.
Use a fabric softener to reduce static problems and wrinkling and to improve the hand.
To reduce pilling, turn articles inside out for washing and drying, use plenty of water, and keep the agitation and tumbling periods short.
Polyester
If nylon is the king of synthetics, polyester is the queen. Like nylon, it is produced from substances derived from coal, petroleum, air, and water. Like nylon, its introduction was heralded by an enormously successful advertising campaign whose most memorable moment was the exhibition at a press conference of a man’s suit that had been worn for sixty-seven days, immersed twice in a swimming pool, machine-washed, and never pressed. The suit was still wearable.
Polyester fiber comes in many chemical and structural varieties, each with characteristics different from the others, some expensive and some inexpensive. Polyester filaments of different shapes may be created, and these will have distinct properties in use. The basic solution out of which the filaments are made may be modified by chemical additions that produce various effects, or special finishes may be applied to the filaments. As with other synthetics and silk, the fibers can be rendered into filament yarns or spun yarns. Because so many variations exist, only rough generalizations about polyester are possible.
Properties of Polyester. Many polyester fabrics are crisp and light, but they can be found in medium and heavy weights too. Polyester fabrics are made in both lustrous and nonlustrous versions, napped and not napped, with and without bulk, and in knits and wovens. They tend to drape fairly well. (Fabrics made from spun polyester yarns drape better than those made from filament yarns.) Their hand can be slightly harsh, but in some types, especially newer ones and in “microfiber” versions, the hand can be soft, silky, or satiny, and generally pleasant to the touch. An outstanding characteristic of polyester fabric is its great resilience (wrinkle-resistance); it needs little or no ironing. A highly thermoplastic fiber, polyester readily heat-sets into permanent creases. Ordinary polyester is an inabsorbent, low-wicking, hydrophobic fiber; but modern variants and treatments have been developed to alter these characteristics.
On average, polyester fabrics are quite strong and durable, but they range from relatively weak to exceptionally strong. None of them weakens when wet. Polyester fabric is highly abrasion-resistant, but it tends to pill. There are pill-resistant variants. (These, however, lose some abrasion resistance.) Polyester fabrics have some elasticity but much less than nylon; they do not stretch or bag or shrink.
Polyester fabrics can be warm or cool to wear, depending on their construction. New variants are vaunted as having state-of-the-art heat-insulating capacities. The inabsorbency and nonwicking character of most unmodified polyester, however, means that many find it uncomfortable worn next to the skin, as it traps moisture. There are new types of polyester designed to wick moisture well—some actually have tubes or channels in the fibers through which moisture can pass—and these are said to be more comfortable. There are also variants that are more absorbent. Polyester’s inabsorbency, however, means that it dries quickly and does not stain easily, except by oil, which stains it readily. Most polyester accumulates static electricity, but there are static-resistant variants.
Polyester fabrics are resistant to damage from both alkalies and most acids. Polyesters have good resistance to damage by sunlight, are unaffected by mildew, moths, and other insects, have good colorfastness, and are usually quite impervious to damage by perspiration.
Like some other hydrophobic fabrics, polyester tends to retain body odors. Polyester athletic wear has sometimes received antimicrobial treatments that help to reduce the odor problem. Soil-resistance treatments are sometimes used to help achieve better laundering results.
Caring for Polyester Fabrics. Polyester fabrics may be dry-cleaned or laundered. Because polyester fiber often holds static electricity, it also tends to attract and hold dirt and lint. Any ordinary laundry detergent can be used to launder it, and any ordinary household bleach can be used. But white polyester very often stays white without bleaching. Fairly warm water is safe to use. To reduce pilling, turn garments inside out for laundering and, in top-loading agitator-style washing machines, use plenty of water and less vigorous agitation. To reduce wrinkling, set the machine on the permanent-press cycle or manually set it for slower spin speeds and a final cool-down rinse.
To conquer the oil-stain and odor problems, wash frequently, pretreat the problem areas, and use a presoak or prewash period, plenty of detergent, and warm or hot rather than cold water. (See “A Note on Caring for Synthetic (Hydrophobic) Fibers,” pages 369-70.) One text particularly recommends using pretreatment products that contain organic solvents and detergents that contain grease—or soil-release agents. (See “Pre treatments and prewash stain removers,” in the Glossary of Laundry Products and Additives, page 84.)
When polyester is properly dyed, it is highly colorfast in laundering. But if residual dye remains in the fabric, it can bleed into the laundry water and badly stain certain other fabrics, such as acetate and nylon. To test for this, touch some acetone (acetone nail-polish remover will do) on an out-of-sight spot on a new polyester garment. If you get color removal, wash the garment separately at first.
Drying polyester in a dryer is recommended because the fluffing helps prevent wrinkling, but clothes should be removed promptly from the dryer or wrinkles may be set in. Use the permanent-press cycle, which has an automatic cool-down. Use fabric softener if necessary to soften or reduce static cling. It will probably not be necessary to use it at every laundering.
If properly laundered, polyester fabrics do not wrinkle much, but if any ironing becomes necessary, they should be ironed at a low to medium setting. They will melt with excessive heat.
To reduce pilling, wash and dry polyester garments turned inside out, reduce agitation and tumbling time as much as possible, and use plenty of water; do not crowd the load.
PLA
PLA, trade named “Ingeo,” is a new generic fiber, approved by the FTC in 2002. PLA is the acronym for the polymer from which the fiber is manufactured—polylactic acid or polylactide. Although PLA fibers are synthetic, they are derived from renewable natural resources, including agricultural crops such as corn and sugar beets, and for that reason are sometimes said to be composed of “biopolymers.” According to its manufacturer, Ingeo is compostable in any industrial composting facility. Using PLA rather than petrochemicals, the manufacturer says, requires 20 to 50 percent less energy and produces 50 percent less carbon dioxide. For these reasons, PLA is touted as being more environmentally favorable than polyester.
PLA, or Ingeo, has been described as “advanced polyester,” but, while it shares various characteristics with polyester, the differences between them are substantial. Like polyester, PLA is not absorbent, but it is said to wick moisture better than polyester and to have better overall “moisture management” than polyester, better resistance to ultraviolet light, a lower melting point, and better flame resistance.
PLA, like other synthetics, is versatile and can be manufactured with a silky or a cottony hand. Low dye uptake and poor colorfastness are said to be among its disadvantages. It is used in blends, especially with cotton and wool, as well as in 100 percent Ingeo textile goods.
Qualities said to make PLA suitable for various apparel uses, especially in active sportswear, include its good wicking and moisture management, soft feel or hand, shape retention, strong wrinkle-resistance (resilience), and a high level of overall comfort. Two advantages claimed for PLA, especially in active sportswear uses, are that, unlike polyester, it is not odor-retentive and is less prone to pilling and oil-staining than polyester. But, like polyester, it tends to pick up static electricity in wear and in tumbling dry. It withstands moderately strong acids and the alkalinity of normal laundering.
PLA is also suitable for use in furnishings (where, its manufacturer points out, its UV resistance and lower flammability are advantages), blankets, and throws. It is used to make a fiber fill for pillows and comforters. (Like other synthetic fibers, PLA is also used to make a large variety of nontextile materials, including many types of packaging.)
Caring for PLA. PLA is both launderable and dry-cleanable. As with any new fiber or fabric, follow care labels at least until you gain some familiarity with it. Ordinary laundry detergents are safe for PLA. Wash in cool water (to protect its dyes) with medium to slow spin speed to avoid setting in wrinkles. Turn garments inside out for laundering to reduce any chance of pilling. Do not use bleach. Tumble dry on medium to low and, as with other synthetics, use your dryer’s antiwrinkle option. PLA is quick-drying. Should you encounter problems with static, try a fabric softener. Iron, if necessary, on low.
Acrylics
Acrylic (polyacrylonitrile) and modacrylic are made from petroleum derivatives. The modacrylics are modified acrylics with slightly different properties.
Acrylic tends to be used as a staple fiber in fabrics that are soft and woolly, fluffy, or fuzzy; most acrylic fabrics look and feel like wool. But there are some smooth acrylics and some that feel like cotton fabrics. Acrylic fabrics are made into a wide range of garments and furnishings, from sweaters and sportswear to rugs and draperies. Modacrylics, which can be soft and fleecy or furry, are often used in fake furs, wigs, carpets, and draperies; because they have good flame resistance, they are also used in children’s sleepwear. Both acrylics and modacrylics are well suited to napped and pile constructions.
Properties of Acrylic and Modacrylic. The various types of acrylic and modacrylic fibers bear a family resemblance to one another, but the two fiber families also have some significant differences. Used often as a wool substitute, both have the virtue of being light and warm yet stronger and less expensive than wool. Their strength, however, is less than that of linen, cotton, or silk. Acrylics weaken when wet; modacrylics do not.
Fabrics made from these fibers have fair to good abrasion resistance and very good to excellent resilience (wrinkle-resistance). They tend to pill, but not always. All have little elasticity and do not stretch (unless the yarn is crimped) or sag. They will not shrink unless exposed to high temperatures or steam. Acrylic and modacrylic fibers are thermoplastic and can be heat-set to retain pleats and creases.
Acrylic and modacrylic fabrics have low absorbency and can be uncomfortable in muggy weather. All will hold static electricity unless treated. All are oleophilic—oil-loving—and prone to being stained by oil. They have good to excellent resistance to ultraviolet radiation and usually have good resistance to perspiration. They are unaffected by mildew or by moths or other insects. They have good colorfastness. Modacrylics are flame-resistant. Pilling is a problem with many acrylics. For those who find wool irritating, acrylics are an excellent alternative. Acetone and acetone-containing substances such as nail-polish removers will harm modacrylics.
Caring for Acrylic and Modacrylic Fabrics. The suggestions that follow are generally applicable, but particular finishes or constructions might require different treatment. Pay careful attention to care label instructions on acrylic and modacrylic fabrics. A “Dry-clean only” instruction on a care label may mean that the fabric has been given a water-soluble finish that, if removed by laundering, will leave the fabric with a harsh hand.
Acrylics tend to hold oily soil and body odors. Because they develop static electricity, these fibers also tend to attract and hold dirt. Frequent cleaning, pretreating, presoaking, and using plenty of detergent will help resolve any such problems. Dry cleaning is not usually recommended, but in principle almost all types of acrylic and modacrylic may be dry-cleaned. They may also readily be laundered with mild soap or detergent in cool water—acrylics are highly heat-sensitive and will shrink—on the gentle cycle or by hand, without wringing, rubbing, or twisting. But modacrylic fabrics with a pile construction should usually be dry-cleaned only or treated with a fur-cleaning process. Household bleaches may be used. To avoid static problems, reduce wrinkling, and give a good hand, use a fabric softener.
For those acrylic or modacrylic fibers that are prone to pilling, the problem may yield to the usual precautions: turn such articles inside out for laundering and drying, use plenty of water, and keep the agitation and tumbling periods short. More delicate articles should be hand-washed. If the article is being hand-washed, avoid rubbing or wringing.
Woven and firmly knitted acrylic fabrics should usually be dripped dry. Heavy acrylic knits should be dried flat. Sometimes you can tumble them dry on a low heat, but you must include a cool-down period. Be careful to keep the dryer temperature low.
Ironing may not be necessary at all. If it is, use a low iron setting.
Spandex (Elastane)
Spandex, developed in the 1950s and early 1960s, is the generic name for a group of fibers made of different types of polyurethane. In Europe, and, increasingly, in the United States, fiber content labels often refer to spandex as “elastane.” Spandex fibers are “elastomeric,” that is, very stretchy. And, as everyone knows who has worn fabrics that contain spandex, it is stretchy in a different way from nylon or other stretch fabrics. The fibers of the latter do not really stretch much; their elasticity comes from the straightening out of crimps in the filaments. Spandex, by contrast, can pull out to five or more times its own length and promptly contract to its original size. Its stretchiness makes it ideal for athletic clothes, tights, knits, sportswear, foundation garments, support hose, and swimsuits.
Properties of Spandex. Spandex fibers are rather weak. Nonetheless, they are durable because they have good abrasion resistance and such great elasticity that in ordinary wear they are never stretched far enough to reach their breaking point. They are extremely resilient and flexible, so fabrics of spandex appear smooth, unwrinkled, and neat. Spandex itself does not pill, but fabrics containing spandex often pill because they contain other fibers that do.
Spandex is highly inabsorbent, even more so than polyester. Spandex fabrics are virtually all blends that include only a small percentage of spandex. The other fibers usually make up more than 90 percent of the fabric by weight. Exercise clothes, for example, might be made with a small amount of spandex and a large amount of cotton, producing a fabric that is at once cool, absorbent, and stretchy. It is because these blends have so little spandex that they are so comfortable. Foundation garment and swimsuit fabrics usually include a larger percentage of spandex—from 15 percent to 50 percent.
Spandex has good resistance to light. All types of spandex are unaffected by mildew or by moths or other insects. Colorfastness varies from poor to good. All types of spandex resist damage from seawater, perspiration, body oils, cosmetics, and suntan lotions, which is important in fabrics used for exercise, foundation garments, and swimwear.
Caring for Spandex Fabrics. Because spandex is almost always found in blended fabrics that include much more of the other fibers than of spandex, it is important to read the care and content labels carefully. A rule of thumb in laundering blends, aside from following care instructions, is to use the most conservative procedures required by any fibers present. The suggestions offered below are applicable to spandex alone, not to any fibers it might be blended with.
All spandex fibers can be both dry-cleaned and laundered. They are machine-washable with ordinary soaps and detergents in warm, not hot, water; high heat will damage the elasticity. Wash whites separately. Some care labels on spandex-blend garments recommend drip-drying; if you are careful, you can machine-dry on a low setting. Delicate articles, however, should be hand-washed and line-dried.
White spandex may be yellowed by body oils, perspiration, chlorine bleach, and smog. To avoid yellowing, launder frequently and use a nonchlorine household bleach. Spandex fibers might be weakened or yellowed if exposed to a chlorine bleach. The spandex in swimsuits gradually deteriorates—and loses elasticity—after repeated exposures to the chlorine in swimming pools. (The spandex is usually hidden, however, so that if yellowing also occurs, it often cannot be seen.) Your spandex-blend swimsuits will last longer if you rinse them out after you wear them to swim in chlorinated water. Sodium perborate bleaches are safe for spandex. (See “Bleaches” in the glossary at the end of chapter 4.)
Spandex fibers do not shrink in water, but some will lose elasticity and weaken if exposed to hot water. Avoid high temperatures in the dryer and on the iron. If ironing is necessary, iron quickly on a low setting.
Olefins (Polypropylene)
Olefins are produced from ethylene and from propylene, petroleum by-products that are inexpensive and available in great quantities. The olefin fiber most used in the home is polypropylene. It is a fiber with many excellent traits, as well as a few negative ones that limit its uses. Currently it is used for, among other things, rugs, upholstery fabrics, rope, disposable diapers, and apparel, especially sportswear and activewear. Polyethylene, which is used for furnishings, car upholstery, blinds, and awnings, is omitted from the discussion that follows. It differs substantially in character from polypropylene and is much more limited in use.
Properties of Polypropylene. Polypropylene is extremely lightweight—the lightest of any fiber. It can be made into very lightweight, warm sweaters and blankets. Among its other merits are that it can be made into fabrics that are strong, abrasion-resistant, and wrinkle-resistant. Polypropylene fabrics can be heat-set into creases that are permanent, so long as they are not exposed to high temperatures. Polypropylene fibers are extremely inabsorbent (the least absorbent of all the synthetic fibers). Some assert that polypropylene wicks extremely well, and it has become a popular choice for active sportswear. Whether or not polypropylene fibers actually wick well, however, is a matter of debate. Unlike a fabric made from a hydrophilic, absorbent fiber such as cotton, polypropylene fabric will not become soaked with perspiration and lose its heat-insulating ability; thus it has been favored for cold-weather sports-wear. And unlike many other synthetic fibers, it resists static buildup. Polypropylene is not harmed by mildew or by moths or other insects. Pilling is often a problem for polypropylene fabrics.
Other problems that afflict polypropylene fabrics are poor dyeability (which producers have made slow progress in improving), strong sensitivity to heat and light (it has the lowest resistance to ultraviolet radiation of all fibers), extremely low absorbency, and ready susceptibility to oil-staining and odor-holding. Its heat and light sensitivity can be substantially reduced with chemical additives, resulting in fibers with adequate resistance for most uses. Its laundering problems, especially those caused by polypropylene’s oleophilic tendencies, are less tractable.
Caring for Polypropylene Fabrics. Like other hydrophobic, oleophilic fibers, polypropylene is prone to retaining oily soils from, for instance, food spills or the body. On the other hand, it is quite resistant to water-based stains, which can sometimes just be wiped off—a real virtue in carpeting. Dry cleaning is not usually recommended for polypropylene because it shrinks in perchlorethylene, the most commonly used drycleaning fluid; if dry cleaning is recommended, an alternative solvent will be specified on the care label. If dry cleaning is necessary, the cleaner should be made aware of the item’s fiber content.
Unfortunately, polypropylene does not readily launder clean, as it can take neither hot water (it shrinks) nor vigorous agitation. Polypropylene may be washed only in warm or cool water, with gentle agitation. Most soaps, detergents, and bleaches may be used. Because it is prone to oil-staining and holding body odors, getting it really clean and fresh is difficult. Polypropylene tends to be low in static, but if you do have a static problem, use a fabric softener. Because it is quite heat sensitive, line-dry or tumble dry polypropylene with cool air or at the lowest dryer setting followed by a cool-down period. It dries very readily, so do not be tempted to turn up the heat out of fear that otherwise it will take forever to dry. Be most careful with irons! If an iron touches polypropylene fabric, it may melt; using a press cloth with a cool iron is wise.
“Lastol” is, technically, a generic subclass fiber name (approved by the FTC in 2003) that may be used as an alternative to the name “olefin.” This means that it is different enough from olefin to merit separate identification on fiber content labels. Lastol is a stretch fiber that is both considerably more elastic and more heat—and chemical-resistant than olefin. Lastol also has the advantage of being resistant to drycleaning chemicals that harm olefin. Its manufacturers describe it as having a cottony hand with a natural feel to it. So far, it is used in easy-care stretch apparel, cotton shirts, garment-washed denim, casual and quality shirts, blouses, professional wear, and uniforms.
Lastol is dry-cleanable and readily launderable. Its manufacturers say that it will not shrink or lose its shape or stretch recovery even after multiple launderings or dry cleanings. Hot water, tumbling dry, and bleach are all safe for lastol, but, as with any new fiber or fabric, follow care labels until you gain experience with it.
Microfibers
Microdenier, or microfiber, fabrics are woven from superfine fibers. You will sometimes see the term “microfiber” used to refer solely to polyester microfibers, these being the most familiar in apparel, but there are also rayon, nylon, and acrylic microfibers.
Only in the past decade have manufacturers begun to produce superfine fibers or microfibers, generally defined as those of less than one denier. The sizes of silk and man-made fibers are specified in “deniers,” or in terms of their linear density. One denier of a given fiber is defined as the weight in grams of 9,000 meters of the fiber. For example, if 9,000 meters of polyester weighed 1 gram, this polyester would be 1-denier; if 9,000 meters of it weighed 3 grams, it would be 3-denier. (A “tex” is 1/9 of a denier, or the weight in grams of 1,000 meters of fiber.) Higher deniers (or tex numbers) imply bigger (greater diameter) fibers, but because different kinds of fibers have different weights, you cannot conclude that 1-denier nylon is the same diameter as 1-denier polyester. The first microfibers were 1-denier, or about the same denier as silk. Now manufacturers sometimes use even “ultrafine” microfibers, with a denier of 0.3 or less. Until these developments, man-made fibers were either fine (less than or equal to 2.2 denier), medium (2.2 to 6.3 denier), or coarse (between 6.3 and 25 denier).
A yarn composed of microfibers contains more filaments and has more surface area than yarn with the same diameter that is composed of regular fibers. This produces a number of effects. All microfiber fabrics tend to have a very soft, silky hand, excellent drapability and strength, and great abrasion-resistance. They are warmer (because they trap more air) and have improved moisture wicking, which contributes to improved comfort. They resist pilling. They are well suited for outerwear, providing both excellent water-repellancy and good breathability. They can also show superb color contrasts in prints. Microfibers frequently contribute to excellent blends.
Despite the improvement in hand, some observers say that microfibers still look synthetic and lack the beauty of natural fibers. They tend to be expensive—often as expensive as silk—and they tend to retain the general characteristics of whatever synthetic they are made of. For example, polyester microfibers are inabsorbent, may oil-stain, and may develop static unless they receive modifications or treatments to control such problems. Microfibers may be more heat sensitive because their thin fibers are more readily penetrated by heat. One reliable source recommends that you use only a cool iron on polyester and nylon microfibers to avoid glazing or melting the fabric and that you avoid applying heavy pressure with an iron, which can cause shine and ridges on the fabric.
Blends
Blends are fabrics that contain two or more fibers, which may be natural, synthetic, or both. The qualities of blends depend on the proportions of each fiber in the blend and on the finishes and treatments that are applied to it. In judging the characteristics of blends, a rule of thumb is that the resulting fabric will have the properties of each fiber in the degree to which that fiber is present in the blend. The most successful blends unite the best qualities of the blended fibers, but there are often trade-offs. Cotton/polyester blends are more wrinkle-resistant than 100 percent cotton fabrics and more comfortable than 100 percent polyester fabrics. However, they can pill (like polyester) and overall may be more likely to stain than either polyester or 100 percent cotton because they may contain the vulnerabilities of both fibers. Blends improperly made or cared for may lose shape or pucker if one fiber shrinks and the other does not. Skillfully made blends, however, often unite superb looks, easy care, and excellent performance.
Examples of deservedly popular blends are far too numerous to list. Cotton/rayon blends often have better crispness, luster, sheen, and hand than a fine 100 percent cotton fabric. With the proper treatments, cotton/rayon blends may also have better shape retention, washing properties, and strength than 100 percent cotton given similar treatments. Rayons with good resistance to alkalies can be mercerized in cotton blends, and wrinkle-resistance treatments weaken them less than they weaken cotton or other types of rayon. Rayon or cotton will contribute good hand, looks, and absorbency when blended with polyester, acrylic, triacetate, or nylon.
A polyester/rayon or polyester/cotton blend is likely to look and feel better than 100 percent polyester but will often fall short of the comfort and good hand of a fabric containing all cotton or rayon or a fabric with a higher percentage of cotton or rayon. The more polyester the article contains, the more wash-and-wear properties it will have, but a higher percentage of cotton or rayon than polyester will give the fabric greater absorbency and a better hand. When cotton/polyester blends are given wrinkle-resistance treatments, polyester’s strength is important because cotton is weakened by the finishing process.
Blended with wool, polyester and other synthetics enhance abrasion resistance and easy-care properties (wrinkle-resistance, crease retention) and help to prevent sagging, bagging, and stretching. The wool adds beauty, warmth, and elasticity. The greater the percentage of wool, the warmer the blend will be and the less likely to pill (but not all such blends are prone to pilling). A garment of wool and triacetate is cooler, more wrinkle-resistant, and holds its shape better than wool alone.
A Note on Caring for Synthetic (Hydrophobic) Fibers and Their Blends
Hydrophilic fibers (all the natural fibers as well as rayon and lyocell) absorb both oily and water-soluble soils, but since they also absorb water and detergent very readily, they tend to give up both types of soil easily too. Man-made fibers such as polyester, nylon, triacetate and acetate, spandex, polypropylene (olefin), acrylic, and modacrylic are all, to one degree or another, hydrophobic. Polypropylene and polyester are exceedingly hydrophobic, and nylon is moderately so. Hydrophobic fibers do not readily absorb water; they may even repel it, and it takes them longer to get wet. They do, however, readily retain oil (they are oleophilic) and do not readily give it up. On the positive side, this means that they shrink less and tend to repel water-based stains, such as coffee and sugary stains, just as they tend to repel water. On the negative side, because it is so hard to get them good and wet, it can also be hard to get them good and clean—especially when it comes to oily dirt and stains, such as greasy tomato sauce. They may retain body odors and oils. Fabrics made from synthetic fibers tend to pill.
Synthetic fibers, for the foregoing reasons, in most ways require the same type of laundering as resin-treated cottons and cotton blends. Laundering frequently, pretreating (particularly with solvent-containing pretreatment products), using plenty of detergent and water, and using the warmest water the fiber will tolerate—all the procedures recommended for resin-treated cloth—help conquer the oily soil and odor problems that you sometimes experience with synthetics. Turning garments made of synthetic fibers or their blends inside out helps too, as this reduces pilling. Use the permanent-press cycle on your washer, with its cool-down rinse and slower spin, with plenty of water, and avoid overcrowding so as to reduce or avoid wrinkling and excess abrasion in the washer; the dryer’s permanent-press setting, too, includes a cool-down period so that hot clothes do not sit and wrinkle.
Because hydrophobic fibers resist wetting, the main trick in laundering them is to leave them in the water for a longer time than you ordinarily need with cottons and linens. The best way to do this is with a good long presoak with plenty of detergent or a presoak product in the hottest water safe for the fiber. You can also increase the wash/agitation period, but this increases the amount of abrasion the fabric is exposed to and hence may increase pilling too.
If oil stains will not respond to laundering, drycleaning solvents or stain removers containing drycleaning solvents, whether used professionally or at home, will often work. If you use them yourself, observe all cautions on labels. They are highly flammable.
Soil-release treatments are often applied to synthetic and wrinkle-treated fibers. These are chemical finishes that make the fibers more absorbent and hence more wettable. They work well at improving the washability of these fabrics for as long as they last, but such treatments tend to become less effective over time. Some last longer than others. If treated with soil-release finishes, permanent-press clothes will generally wash free of both oil—and water-based stains in ordinary home washing procedures. Some types of durable-press and wash-and-wear fabrics are treated with antimicrobials to reduce odor problems.