Fabric softener

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A fabric softener (American English) or fabric conditioner (British English) is a conditioner that is applied to laundry after it has been washed in a washing machine. A similar, more dilute preparation meant to be applied to dry fabric is known as a wrinkle releaser.

Contents

A fabric softener reduces the harsh feel of items that were dried in open-air, adds a fragrance to the laundry, and/or imparts anti-static properties to textiles. In contrast to laundry detergents, fabric softeners may be regarded as a kind of after-treatment laundry aid. [1]

Fabric softeners are either in the form of a liquid that is typically added during the washing machine rinse cycle, or as a dryer sheet which is added to a tumble dryer before drying begins. [1] [2] Liquid fabric softeners may be added manually during the rinse cycle, automatically if the machine has a dispenser designed for this purpose, through use of a dispensing ball, or poured onto a piece of laundry to be dried (such as a wash cloth) which is then put into the dryer.

Washing machines put great mechanical stress on textiles, particularly natural fibers such as cotton and wool. The fibers at the fabric's surface are squashed and frayed, and this condition hardens into place when drying the laundry in open-air, giving the textiles a harsh feel. Using a tumble dryer results in a softening effect, but it is less than what can be achieved through the use of a fabric softener. [3] [1]

As of 2009, nearly 80% of US households had a mechanical clothes dryer. [4] As such, fabric softeners are primarily used there to impart anti-static properties and/or a fragrance to laundry.

Mechanism of action

Fabric softeners coat the surface of a fabric with chemical compounds that are electrically charged, causing threads to "stand up" from the surface and thereby imparting a softer and fluffier texture. Cationic softeners bind by electrostatic attraction to the negatively charged groups on the surface of the fibers and neutralize their charge. The long aliphatic chains then line up towards the outside of the fiber, imparting lubricity.

Fabric softeners impart anti-static properties to fabrics, and thus prevent the build-up of electrostatic charges on synthetic fibers, which in turn eliminates fabric cling during handling and wearing, crackling noises, and dust attraction. Also, fabric softeners make fabrics easier to iron and help reduce wrinkles in garments. In addition, they reduce drying times so that energy is saved when softened laundry is tumble-dried. Additionally, they can also impart a pleasant fragrance to the laundry. [1]

Fabric softeners

Early cotton softeners were typically based on a water emulsion of soap and olive oil, corn oil, or tallow oil.[ citation needed ] Softening compounds differ in affinity to various fabrics. Some work better on cellulose-based fibers (i.e., cotton), others have higher affinity to hydrophobic materials like nylon, polyethylene terephthalate, polyacrylonitrile, etc. New silicone-based compounds, such as polydimethylsiloxane, work by lubricating the fibers. Manufacturers use derivatives with amine- or amide-containing functional groups as well. These groups improve the softener's binding to fabrics.

As softeners are often hydrophobic, they commonly occur in the form of an emulsion. [5] In the early formulations, manufacturers used soaps as emulsifiers. The emulsions are usually opaque, milky fluids. However, there are also microemulsions, where the droplets of the hydrophobic phase are substantially smaller[ not specific enough to verify ]. Microemulsions provide the advantage of increased ability of smaller particles to penetrate into the fibers. Manufacturers often use a mixture of cationic and non-ionic surfactants as an emulsifier. Another approach is a polymeric network, an emulsion polymer.

In addition to fabric softening chemicals, fabric softeners may include acids or bases to maintain optimal pH for absorption, silicone-based anti-foaming agents, emulsion stabilizers, fragrances, and colors.

Cationic fabric softeners

Rinse-cycle softeners usually contain cationic surfactants of the quaternary ammonium type as the main active ingredient. Cationic surfactants adhere well to natural fibers (wool, cotton), but less so to synthetic fibers. Cationic softeners are incompatible with anionic surfactants in detergents because they combine with them to form a solid precipitate. This requires that the softener be added in the rinse cycle. [6] Fabric softener reduces the absorbency of textiles, which adversely affects the function of towels and microfiber cloth. [7] [ failed verification ]

Formerly, the active material of most softeners in Europe, the United States, and Japan, was distearyldimethylammonium chloride (DSDMAC) or related quat salts. Due to their poor biodegradability, such tallow-derived compounds were replaced by the more labile ester-quats in the 1980s and 1990s.

Conventional softeners, which contain 4–6% active material, have been partially replaced in many countries by softener concentrates having some 12–30% active material.

Anionic fabric softeners

Anionic softeners and antistatic agents can be, for example, salts of monoesters and diesters of phosphoric acid and the fatty alcohols. These are often used together with the conventional cationic softeners. Cationic softeners are incompatible with anionic surfactants in detergents because they combine with them to form a solid precipitate. This requires that they be added in the rinse cycle. Anionic softeners can combine with anionic surfactants directly. Other anionic softeners can be based on smectite clays. Some compounds, such as ethoxylated phosphate esters, have softening, anti-static, and surfactant properties. [8]

Risks

As with soaps and detergents, fabric softeners may cause irritant dermatitis. [9] Manufacturers produce some fabric softeners without dyes and perfumes to reduce the risk of skin irritation. Fabric softener overuse may make clothes more flammable, due to the fat-based nature of most softeners. Some deaths have been attributed to this phenomenon, [10] and fabric softener makers recommend not using them on clothes labeled as flame-resistant. [11]

Additional reading

Related Research Articles

<span class="mw-page-title-main">Detergent</span> Surfactants with cleansing properties

A detergent is a surfactant or a mixture of surfactants with cleansing properties when in dilute solutions. There are a large variety of detergents, a common family being the alkylbenzene sulfonates, which are soap-like compounds that are more soluble in hard water, because the polar sulfonate is less likely than the polar carboxylate to bind to calcium and other ions found in hard water.

<span class="mw-page-title-main">Surfactant</span> Substance that lowers the surface tension between a liquid and another material

Surfactants are chemical compounds that decrease the surface tension or interfacial tension between two liquids, a liquid and a gas, or a liquid and a solid. Surfactants may function as emulsifiers, wetting agents, detergents, foaming agents, or dispersants. The word "surfactant" is a blend of surface-active agent, coined c. 1950.

<span class="mw-page-title-main">Laundry</span> Washing of clothing and other textiles

Laundry refers to the washing of clothing and other textiles, and, more broadly, their drying and ironing as well. Laundry has been part of history since humans began to wear clothes, so the methods by which different cultures have dealt with this universal human need are of interest to several branches of scholarship.

<span class="mw-page-title-main">Washing machine</span> Machine that washes clothes automatically

A washing machine is a home appliance used to wash laundry. The term is mostly applied to machines that use water as opposed to dry cleaning or ultrasonic cleaners. The user adds laundry detergent, which is sold in liquid, powder, or dehydrated sheet form, to the wash water.

<span class="mw-page-title-main">Dry cleaning</span> Cleaning of fabrics in non-aqueous solvents

Dry cleaning is any cleaning process for clothing and textiles using a solvent other than water.

<span class="mw-page-title-main">Clothes dryer</span> Appliance used for drying wet clothes

A clothes dryer, also known as tumble dryer or simply dryer, is a powered household appliance that is used to remove moisture from a load of clothing, bedding and other textiles, usually after they are washed in a washing machine.

<span class="mw-page-title-main">Quaternary ammonium cation</span> Polyatomic ions of the form N(–R)₄ (charge +1)

In organic chemistry, quaternary ammonium cations, also known as quats, are positively-charged polyatomic ions of the structure [NR4]+, where R is an alkyl group, an aryl group or organyl group. Unlike the ammonium ion and the primary, secondary, or tertiary ammonium cations, the quaternary ammonium cations are permanently charged, independent of the pH of their solution. Quaternary ammonium salts or quaternary ammonium compounds are salts of quaternary ammonium cations. Polyquats are a variety of engineered polymer forms which provide multiple quat molecules within a larger molecule.

<span class="mw-page-title-main">Laundry detergent</span> Type of detergent used for cleaning laundry

Laundry detergent is a type of detergent used for cleaning dirty laundry (clothes). Laundry detergent is manufactured in powder and liquid form.

<span class="mw-page-title-main">Carboxymethyl cellulose</span> Cellulose derivative grafted with carboxymethyl groups

Carboxymethyl cellulose (CMC) or cellulose gum is a cellulose derivative with carboxymethyl groups (-CH2-COOH) bound to some of the hydroxyl groups of the glucopyranose monomers that make up the cellulose backbone. It is often used as its sodium salt, sodium carboxymethyl cellulose. It used to be marketed under the name Tylose, a registered trademark of SE Tylose.

<span class="mw-page-title-main">Dispensing ball</span> Ball used to dispense fabric softener in clothes washing machines

A dispensing ball is a special plastic ball used to dispense liquid fabric softener in clothes washing machines that lack built-in softener dispensers. Liquid fabric softener has to be added at the correct time to a load of laundry in order to work effectively. In top-loading machines, the ball accomplishes this with no user input, other than the initial loading, and filling of the ball.

Softener may refer to:

<span class="mw-page-title-main">Dryer ball</span> Laundry device for tumble dryers

A dryer ball is a spherical laundry device for tumbling clothes dryers used as an alternative to fabric softener, reducing static electricity or softening clothing, or to accelerate the drying process.

<span class="mw-page-title-main">Finishing (textiles)</span> Manufacturing process

In textile manufacturing, finishing refers to the processes that convert the woven or knitted cloth into a usable material and more specifically to any process performed after dyeing the yarn or fabric to improve the look, performance, or "hand" (feel) of the finish textile or clothing. The precise meaning depends on context.

Paint has four major components: pigments, binders, solvents, and additives. Pigments serve to give paint its color, texture, toughness, as well as determining if a paint is opaque or not. Common white pigments include titanium dioxide and zinc oxide. Binders are the film forming component of a paint as it dries and affects the durability, gloss, and flexibility of the coating. Polyurethanes, polyesters, and acrylics are all examples of common binders. The solvent is the medium in which all other components of the paint are dissolved and evaporates away as the paint dries and cures. The solvent also modifies the curing rate and viscosity of the paint in its liquid state. There are two types of paint: solvent-borne and water-borne paints. Solvent-borne paints use organic solvents as the primary vehicle carrying the solid components in a paint formulation, whereas water-borne paints use water as the continuous medium. The additives that are incorporated into paints are a wide range of things which impart important effects on the properties of the paint and the final coating. Common paint additives are catalysts, thickeners, stabilizers, emulsifiers, texturizers, biocides to fight bacterial growth, etc.

Wet Processing Engineering is one of the major streams in Textile Engineering or Textile manufacturing which refers to the engineering of textile chemical processes and associated applied science. The other three streams in textile engineering are yarn engineering, fabric engineering, and apparel engineering. The processes of this stream are involved or carried out in an aqueous stage. Hence, it is called a wet process which usually covers pre-treatment, dyeing, printing, and finishing.

Wastewater comes out of the laundry process with additional energy (heat), lint, soil, dyes, finishing agents, and other chemicals from detergents. Some laundry wastewater goes directly into the environment, due to the flaws of water infrastructure. The majority goes to sewage treatment plants before flowing into the environment. Some chemicals remain in the water after treatment, which may contaminate the water system. Some have argued they can be toxic to wildlife, or can lead to eutrophication.

Wax emulsions are stable mixtures of one or more waxes in water. Waxes and water are normally immiscible but can be brought together stably by the use of surfactants and a clever preparation process. Strictly speaking a wax emulsion should be called a wax dispersion since the wax is solid at room temperature. However, because the preparation takes place above the melting point of the wax, the actual process is called emulsification, hence the name wax emulsion. In praxis, wax dispersion is used for solvent based systems.

Wrinkle-resistant or permanent press or durable press is a finishing method for textiles that avoids creases and wrinkles and provides a better appearance for the articles. Most cellulosic fabrics and blends of cellulosic rich fabrics tend to crease or wrinkle. A durable press finish makes them dimensionally stable and crease free. The finishing includes chemical finishing as well as mechanical finishing. Wrinkle-resistant finishes were developed in the early 20th century, as a way to deal with fabrics derived from cotton, rayon, and linen, which were found to wrinkle easily and retain the wrinkles. These treatments have a lasting effect on the fabric. Synthetics like polyester, nylon, acrylic and olefin, have a natural resistance to wrinkles and a greater stability since they do not absorb water as efficiently.

<span class="mw-page-title-main">Fabric treatment</span>

Fabric treatments are processes that make fabric softer, or water resistant, or enhance dye penetration after they are woven. Fabric treatments get applied when the textile itself cannot add other properties. Treatments include, scrim, foam lamination, fabric protector or stain repellent, anti microbial and flame retardant.

References

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  2. Jones, C. R.; Corona, A.; Amador, C.; Fryer, P. J. (2022-07-15). "Dynamics of fabric and dryer sheet motion in domestic clothes dryers". Drying Technology. 40 (10): 2087–2104. doi: 10.1080/07373937.2021.1918706 . ISSN   0737-3937. S2CID   236596597.
  3. Eduard Smulders; Wolfgang Rybinski; Eric Sung; Wilfried Rähse; Josef Steber; Frederike Wiebel; Anette Nordskog (2007). "Laundry Detergents". Ullmann's Encyclopedia of Industrial Chemistry . Weinheim: Wiley-VCH. pp. 86–87. doi:10.1002/14356007.a08_315.pub2.
  4. "ENERGY STAR Market & Industry Scoping Report: Dryers" (PDF). Energy Star. United States Government. p. 3. Retrieved 15 December 2023.
  5. Kumar, Asim; Choudhury, Roy (2017). "6 - Softening". Principles of Textile Finishing. Woodhead Publishing Series in Textiles. pp. 109–148. doi:10.1016/B978-0-08-100646-7.00006-0. ISBN   9780081006467 via Science Direct.
  6. Wang, Linda (14 Apr 2008). "Dryer Sheets — The science that gives clothing a soft feel and fresh scent as it prevents static cling". Chemical and Engineering News . 86 (15): 47. ISSN   0009-2347.
  7. Morrison, Chris (2009-11-30). "How Dryer Sheets Work". HowStuffWorks. Retrieved 2021-01-17.
  8. "Fabric softener and anti-static compositions – Patent 4118327". Freepatentsonline.com. 1977-03-28. Retrieved 2009-06-04.
  9. "Contact dermatitis". Medline. Retrieved 2015-10-24.
  10. "Liquid fabric softener may make clothes more flammable: Quebec coroner". CBC. Retrieved 2015-11-20.
  11. Heloise (2001-11-28). "Cleaning Flame-Retardant Clothing". Good Housekeeping. Retrieved 2020-12-06.