Disposable Diaper

Disposable diapers used in hospitals typically consist of a iii-layer composite article [v, 6]: (i) an inner covering layer, which is either a longitudinally orientated polyester web treated with a hydrophilic finish or a spun-laid polypropylene nonwoven textile;

From: Applied science Textiles (Second Edition) , 2020

Developments in the use of nonwovens for dispensable hygiene products

J.R. Ajmeri , C.J. Ajmeri , in Advances in Technical Nonwovens, 2016

xviii.2.1 Diapers

Disposable diapers and incontinence pads for the personal intendance market place are rapidly improving. Currently, this market place is seeing low growth in areas like the United states and Western Europe, where penetration levels are high and birth rates substantially lower compared to developing countries.

Growth in the babe diaper market is beingness driven by 2 primal factors: purchasing power parity and the population pyramids. It is articulate the emerging markets, particularly in Asia, with low diaper penetration and rapidly growing consumer income levels are driving futurity diaper book growth.

Disposable diapers are the third largest single consumer detail in landfills, and represent about 4% of solid waste. In a house with a child in diapers, disposables make up 50% of household waste. Disposable diapers generate 60 times more than solid waste material and apply twenty times more than raw materials, like rough oil and wood pulp. The manufacture and use of disposable diapers amount to 2.three times more water wasted than cloth. Over 300 pounds of wood, 50 pounds of petroleum feedstocks, and xx pounds of chlorine are used to produce disposable diapers for one baby each twelvemonth. Dispensable diapers comprise traces of dioxin, an extremely toxic by-production of the paper-bleaching procedure. It is carcinogenic chemic, the most toxic of all cancer-linked chemicals. (Realdiapers.org/diaper-facts, 2015; Shin & Abu, 2007).

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Smell IN RELATION TO Different POLYMERS

George Wypych , in Handbook of Odors in Plastic Materials (Second Edition), 2017

8.13 POLYACRYLATE

Polyacrylate polymers are used equally superabsorbents in consumer products. 61 Disposable diapers and sanitary napkins are some of the products concerned. 61 The problems surfaced when consumers complained about an off-odor in these products. 61 Solid superabsorbent polymers were non odorous, but some became highly odorous when wet. 61 This observation suggested the interest of volatile hydrophobic compounds. 61 Removal of vinyl ketones, and especially the five-methylhex-one-en-3-one, from the monomers, used to set the polymers resulted in improved materials with lilliputian odor. 61

Polyacrylate polymer is used as a thickener in hypochlorite solutions used every bit bleach compositions. 62 Some bleach compositions have a strong unpleasant odor. It was found that by the regulating viscosity of solution with polyacrylate, the size of sprayed mist can exist decreased and the yield value of liquid increased, which reduces scent. 62

The superabsorbent material for the absorbent core contains polyacrylate-based material. 63 The hydrogen in water is trapped by the polyacrylate due to the atomic bonds associated with the polarity forces between the atoms. 63 Polyacrylate provides an effective liquid fragrance or olfactory property command limerick which does non alter the backdrop of the adhesive. 63

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Applications of Polypropylene Films

Teresa Calafut , in Plastic Films in Food Packaging, 1998

6.4.v Nonwovens

Nonwoven fabrics are used in sanitary products, surgical garments, geotextiles, and other applications. In sanitary products—disposable diapers, feminine hygiene products, and developed incontinence aids—a soft nonwoven encompass stock maintains dryness and comfort. Fibers accept high tear strength, even when wet, and moisture is transported through the textile. Disposable surgical nonwovens, including shoe covers, gowns, caps, and bedding, are economical and ensure proper sanitation. Nonwoven bouffant caps, wipes, and cleaning pads are used in restaurants and nutrient service areas to go along food training areas costless of contamination. Other uses include carpet backing, mattress pads, cushions, vacuum cleaner bags, overnight courier envelopes, and automotive car covers.

Protective garments prevent contamination of sensitive appliances in ultraclean rooms past workers. Agricultural nonwovens provide air, light, and water permeability to seeds and plants and protect against cold, bad weather condition, and insect pests. As a result, early sowing is possible, and plants grow well, with a high yield (Hereafter—The Hoechst Magazine, 1992; Inform—Hostalen PP, 1995; Polyolefin: Because It Works).

Several applications of textiles and nonwoven fabrics are shown in Effigy half-dozen.13.

Effigy half-dozen.thirteen. Polypropylene applications in textiles and nonwoven fabrics. (a) Rope, (b) outdoor apparel, (c) geotextiles, (d) and (e) woven filters, (f) disposable diapers, (yard) packing numberless (Big Purse), (h) surgical garments, and (i) automotive upholstery and automotive interior cladding function with trim ( Amoco Polypropylene Homopolymers, 1992; Inform—Hostalen PP, 1995; Polyolefin: Considering Information technology Works; Precision Woven Screening Media, 1997 ).

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Miscellaneous Topics

Pratima Bajpai , in Biermann's Handbook of Lurid and Paper (Third Edition), 2018

25.eleven Superabsorbency

Superabsorbent polymers (SAPs) have been used in hygiene products since the late 1960s (Masuda, 1993). Nearly 250,000 tons are used globally each year, nigh of which are used in disposable diapers for babies. Most SAPs for hygiene products are the sodium salts of moderately cantankerous-linked polyacrylic acid (not all of the acid groups are in the common salt course) in a dry out pulverization of 300   μm particles. The cross-linking agents are typically glycol diacrylate or N,N′-methylenebisacrylamide. Residual monomer (which may be a skin irritant) levels are now beneath 100   ppm.

The famous polymer scientist P. J. Flory had theoretically adamant the important parameters for h2o absorption by polymers. The important factors for absorption capacity include a polymer with a high analogousness for h2o (i.east., a polar polymer), a depression cross-linking density in the polymer (just enough to continue the polymer insoluble), and a high ion density on the polymer.

Electrolytes dissolved in the water to exist captivated subtract the amount of water ultimately absorbed by the cross-linked polymer, and hither the type of electrolyte is of import, with polyvalent cations decreasing absorption to a higher degree than monovalent cations (as expected from colloid chemical science principles); these factors become important when SAP systems are extended to nonhygiene product uses such as those pressed between two papers and used in sheet form.

The rate of absorption is determined by physical backdrop, especially the surface area of the SAP. Effectively particles generally blot faster, although if the particle size is too pocket-sized, a viscid material is obtained that does non blot water quickly. Masuda (1993) states that diaper dryness is correlated to absorbency under load (AUL, r  =   0.81) and diaper leakage is inversely correlated to gel stability (r  =   0.93). The tendency has been to use lower amounts of fluff fiber and college levels of SAP in hygiene products; these products may be every bit much as thirty% SAP.

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Myths and Ideology: Perception versus Reality

Daniel A. Vallero Ph.D. , in Paradigms Lost, 2006

Solid Waste matter: Is It Taking over the Planet?

Municipal solid waste product (MSW), 1 the trash or garbage collected by towns, cities, and counties, is fabricated up of commonly used and disposed of items like lawn waste matter and grass clippings, boxes, plastics and other packaging, piece of furniture, vesture, bottles, food scraps, newspapers, appliances, paint, and batteries. In 2001, U.Due south. residents, businesses, and institutions produced more than 229 million tons of MSW, which is approximately 4.4 pounds of waste product per person per mean solar day, up from 2.7 pounds per person per day in 1960 (see Figure ten.one).

FIGURE 10.i. Composition of waste product generated in the United States in 2001.

 Source: U.S. Environmental Protection Agency, 2005. Municipal Solid Waste, http://www.epa.gov/epaoswer/not-hw/muncpl/facts.htm; accessed April 5, 2005.

The amount of solid waste matter generated in the United States has grown steadily (run into Figure 10.2), and near every local authority since the 1990s has implemented management practices to stalk the burgeoning amounts of solid waste beingness generated and needing disposal. These measures have included source reduction, recycling and composting, and prevention or diversion of materials from the waste matter stream. Source reduction involves altering the design, industry, or use of products and materials to reduce the amount and toxicity of what gets thrown abroad. Recycling averts items from reaching the landfill or incinerator. Such items include paper, glass, plastic, and metals. These materials are sorted, collected, and processed and then manufactured, sold, and bought as new products. Composting is the microbial decomposition of the organic fraction of wastes, such every bit food and one thousand trimmings. The microbes, mainly bacteria and fungi, produce a substance that is valuable as a soil conditioner and fertilizer, which is sold or given away by the local government, often at the landfill site itself.

FIGURE 10.2. Trends in municipal solid waste generation. Up to the late 1980s, the charge per unit of waste generated per capita was proportional to the full waste generated. After that time, in part due to waste reduction and recycling programs, the waste generated per capita dropped, but the full waste generated continued the upwards pace.

Engineers and ecology professionals have also improved waste handling once the items discover their style to the landfill. For instance, landfills must be engineered in a fashion and in areas where waste matter is placed into the land (see Tabular array ten.1) . Landfills usually have liner systems and other safeguards to prevent groundwater contagion. Combusting solid waste is another practice that has helped reduce the amount of landfill space needed. Combustion facilities burn down solid wastes at high temperatures, reducing waste volume and generating electricity.

TABLE 10.i. Summary of federal landfill standards equally prescribed by the U.South. Environmental Protection Agency, 2005. http://www.epa.gov/epaoswer/non-hw/muncpl/landfill; accessed Apr 22, 2005.

Location restrictions ensure that landfills are built in suitable geological areas away from faults, wetlands, flood plains, or other restricted areas.
Liners are geomembrane or plastic sheets reinforced with two feet of dirt on the lesser and sides of landfills.
Operating practices such as compacting and covering waste ofttimes with several inches of soil help reduce odor; control litter, insects, and rodents; and protect public wellness.
Groundwater monitoring requires testing groundwater wells to decide whether waste materials have escaped from the landfill.
Closure and postclosure care include covering landfills and providing long-term care of closed landfills.
Corrective action controls and cleans up landfill releases and achieves groundwater protection standards.
Financial assurance provides funding for ecology protection during and later on landfill closure (i.e., closure and postclosure intendance).

This is all well and skilful, and demonstrates great progress in how we think most wastes. Nevertheless, there is an argument that the original premise on which this progress is based is, in fact, flawed. Are we really facing a solid waste crunch? Talk show hosts and a contempo Dwelling Box Office show hosted by the comedy team, Penn and Teller, consider the solid waste material problem to be a user-friendly myth. One of their postulations is that the outcome is another way that the authorities interferes with privacy and freedoms. In fact, 1 of Penn and Teller'south conclusions is that the recycling is okay, but the ends should not justify the means. They argue that information technology is unethical to control people's lives based on a flawed premise.

The controversy cuts both ways. Others believe that the progress being fabricated is overstated and that measures to reduce waste, for example, looking at simply total volume reduced, are inadequate considering pockets of intractable problems exist. Take "disposable" diapers, for instance. A cloth diaper service, with an obvious vested interest, argues:

An entire generation is growing up assertive that the term "dispensable diaper" is redundant: There's only one thing you put on babies' bottoms. They're plastic, y'all get them in huge bags and boxes at the grocery store or the convenience store, and you fold them up, and toss them in the trash when they're muddy. The production name itself is a misnomer, testament to the power of Madison Avenue and to our own Freudian neuroses surrounding our bodies and our wastes. For Huggies and Pampers and Luvs are not "disposable" at all. Nosotros throw about 18 billion of them away each year into trash cans and bags, believing they've gone to some magic place where they will safely disappear. The truth is, most of the plastic-lined "disposables" end up in landfills. There they sit, tightly wrapped bundles of urine and feces that partially and slowly decompose only over many decades. What started out as a marketer's dream of drier, happier, more than comfortable babies has get a solid-waste matter nightmare of squandered material resource, skyrocketing economic science, and a growing wellness take chances, ready against the backdrop of dwindling landfill chapters in a state driven by consumption. 2

So, even 1 of the nigh successful programs in terms of changing the attitude about waste is bailiwick to controversy.

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The Trouble of Marine Plastic Debris

Michael Niaounakis , in Management of Marine Plastic Debris, 2017

1.iv.i.vi Sanitary Absorptive Items

Superabsorbent polymers (SAPs) are polymers that can blot and retain their own mass of a liquid many times. For example, a hydrogel (h2o-absorbing SAP) may be able to hold and retain its own weight in deionized and distilled water up to 500 times. SAPs are made of polymers that carry carboxyl groups (COOH) such as polyacrylates, modified starches, polyacrylamide, or other hydrophilic components. The polymer chains are cross-linked past a variety of chemicals and to varying extents.

SAPs were patented by Genre Harper of (1970, GB1200106 A, DOW Chemical) and Carlye Harmon (1970, GB1192581 A, JOHNSON & JOHNSON). They were outset used in diapers in Japan.

Information technology is estimated that 70%–80% of all SAPs are used in the manufacture of sanitary absorbent articles, such every bit dispensable diapers (or nappies), incontinence pads, feminine hygiene pads, sanitary napkins, panty lines, bedpads, and other related absorptive and adsorbent products.

The disposable diapers are made of a diverseness of components comprising wood pulp, plastics (including the SAPs now nowadays in most diapers), tissue newspaper, or polyester nonwoven material, nonpermeable film made, eastward.g., of polyethylene or polypropylene, agglutinative, or hook tapes, etc.

The complexity of the disposable diapers has made traditional recycling impossible to do efficiently and price-effectively with current technologies. As a result, most after-consumer disposable diapers end up as solid waste product piling up in landfills or incineration sites. An estimated 3.6   million   t of disposable diapers were generated in 2005, or 1.v% of full MSW generation. Hundreds of billions of muddy diapers are tending annually equally solid wastes and only a very small fraction of them are recycled. This is mainly due to the lack of technologies for efficient and cost-constructive recycling.

Improperly disposed sanitary absorbent articles can stop upward littering bodies of water and beaches, whereas sanitary absorptive manufactures flushed down the toilet tin can damage the sewage system. Diapers contain small amounts of dioxins, the well-nigh common of which is polychlorinated dibenzodioxin, a mutual environmental pollutant. Dioxins form in the wood pulp when it is bleached with chlorine from brownish to white before existence put into the diaper. Disposed diapers, still containing human waste material, carry also a substantial number of bacteria and other contaminants. Both dioxins and bacteria may leach out of diapers and enter surface water [122].

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Terpene Resins

Johannes Karl Fink , in Reactive Polymers Fundamentals and Applications (2nd Edition), 2013

12.3.ii Copolymers

Copolymers of α -pinene, β -pinene, limonene, styrene, piperylene, cyclopentadiene, and vinyl toluene can be prepared. The monomers are copolymerized with Lewis acid catalysts.

The copolymerization of terpenes with other monomers such as styrene extends their Hildebrand solubility parameter. Such copolymers are compatible with poly(butadiene) rubbers. This copolymer is used in the manufacture of disposable diapers.

Styrenated terpene resins can be produced by a cationic polymerization process using a Lewis acid catalyst. Limonene is used equally the major terpene component [12]. Commercial products of this type are bachelor. A styrenated terpene resin can be used equally a depression-polarity condiment in connection with metal nanoparticles for conductive flexographic inks. These compositions can exist used for the manufacture of electronic components.

The fabrication of electronic excursion elements using metal nanoparticle liquid degradation techniques is of profound interest as such techniques provide potentially depression-price alternatives to conventional mainstream baggy silicon technologies for electronic applications such as sparse-picture transistors, low-cal-emitting diodes, and others [xiii].

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SURFACES, Chemistry & APPLICATIONS

ALBERT I. EVERAERTS , L.K. CLEMENS , in Adhesion Science and Engineering, 2002

7.2.3 High styrene polymers

During this same flow several suppliers [49–51 ] entered the market place identify with somewhat lower molecular weight SIS block copolymers with styrene contents ranging from well-nigh 20 to 35%. Polymers on the low end of this styrene range can be formulated to PSAs with good record properties, while the higher styrene levels are designed for hot-melt formulations that are air sprayable and used in disposable diaper and other dispensable particular manufacturing. For some of these PSA applications, more low-cost oil tin exist loaded into the formulation. Similarly, the high styrene hot-cook formulations may incorporate as trivial as twenty–22% cake copolymer, with the residual tackifier and oil. To get air sprayability, the tackifier bundle may even take an aromatic-aliphatic component, since an all-aliphatic tackifier may edge on incompatible at these high styrene levels. Adding even more than aromatic content to the tackifier may pb to some softening of the styrene stage, but this may exist required to reduce the melt viscosity for the air assisted spraying. This also leads to some reduction in high-temperature shear-holding power, an acceptable trade-off for this type of application.

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The Plastics Industry

Michel Biron , in Thermosets and Composites (Second Edition), 2014

two.11.13 Miscellaneous Applications

•

Polyurethane foams: sponges for cosmetic uses (powder puffs, eye-liner), paramedic (sponges for massage), domestic (toilet, scouring, polish applicators), fabric and habiliment (shoulder pads, fabric lining for wall soundproofing); industrial (impregnation); hygiene (elastic belts for disposable diapers); paint rollers, polishing discs; air filtration: hoods, vacuum cleaners; liquid filtration; phonic damping, forepart panels of loudspeakers, lining of heavy masses.

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Unsaturated polyesters and their composites: buttons, scientific or electricity inclusions, sandable cements for metallic or composite repairs; farm equipment, cabins of transformers, seat cockles, terrace coating, buffing wheels, careenages for race motorbikes, swimming pools.

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Melamines: tablewares, drink glasses, tooth glasses, knives, forks and spoons, "unbreakable" plates and cups, screw caps for nutrient fabricated of foodstuff grades, handles of domestic irons, buttons of lids, handles and buttons of pans, ashtrays.

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Urea-formaldehyde: non-food parts of cute attribute, for case toilet seats, base plates of small-scale household appliances.

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Aramid, glass or polyethylene fiber reinforced composites: ductile ballistic materials that absorb the projectile energy through deformation.

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Vinylester-based BMC for fuel cell plates.

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Superabsorbent polymers and their medical applications

Yimin Qin , in Medical Textile Materials, 2016

vi.9.1 Baby diapers

A diaper (in American and Canadian English) or nappy (in Republic English) is a kind of underwear that allows one to defecate or urinate in a discreet manner. Diapers have been worn throughout human history, and are made of cloth or dispensable materials. Cloth diapers are equanimous of layers of fabric made from cotton wool, hemp, bamboo, or microfibers, and tin can be washed and reused multiple times. Dispensable diapers incorporate absorbent materials and are thrown abroad after use. The conclusion to use textile or disposable diapers is a controversial one, due to problems ranging from convenience, wellness, and price due to their effect on the environment.

Compared to cloth diapers, dispensable diapers have superior urine absorbency, leak protection, dryness, and rash-protection properties. Since modern disposable baby diapers were first introduced in the 1940s and mass produced in the 1960s, the demand for these products has expanded quickly as they became more than affordable for everyday utilise. Since the 1990s a steady stream of technical innovations have farther improved the affordability, part, and comfort of diaper products, enabling disposable diapers to be widely used in developing also as adult nations. The use of SAPs has revolutionized the diaper industry as manufacturers took advantage of the amazing liquid retention ability of these polymers. With refined understanding of the impact of SAPs on the absorbent core, the amount of cellulose pulp fluff used in the diapers was reduced by half, making it possible to produce ultraslim diapers.

During the product process, SAPs in granular or powder forms are added to babe diapers in two ways: layered or composite. In the layered method, powdered SAPs are first scattered on a layer of fluff pulp before it is folded, and then the SAPs are located in a centralized layer in the absorbent structure, which is further covered with a nonwoven cloth layer. In the composite awarding, the SAPs are first mixed homogeneously with the fluff pulp before the mixture is laid downward to form the absorbent structure, which is subsequently covered with a nonwoven fabric.

During the evolution of diapers with improved performance, a split layer of nonwoven fibers was added to improve urine distribution in the diaper. This distribution layer is placed between the composite absorbent cadre, consisting of cellulose fiber and SAPs, and the porous encompass sheet. The distribution layer has a lower absorbency than either the standard cellulose fluff or SAP, thus allowing fast liquid distribution within the diaper. This layer is often made from nonabsorbent nonwoven materials such as polypropylene fibers, with sufficient porosity to allow liquid to pass through freely.

The diaper core is responsible for holding the liquid during the actual utilize of the production, and many aspects must be considered during its design—for example, the absorption charge per unit of the diaper must not be slower than the urination rate of the baby, otherwise leakage will occur. The absorption rate of the diaper's composite structure is influenced by the absorption charge per unit of the SAPs. Fast swelling of the polymer may or may non exist desirable. In some diaper designs, fast swelling may cause the diaper to leak if the porosity and permeability of the composite are reduced, hindering the penetration of the liquid into the inner part of the diaper. Particle size and shape tin can affect the maximum absorption capacity of the polymer, and the placement of fast- or slow-absorbing polymers in the composite construction has important implications for the effectiveness of the composites. The particle size, placement, and relative amounts should be adjusted to reach optimized absorption.

AUL and stability of the gel against shear are important properties of SAPS, and relate strongly to diaper operation. Diaper leakage is closely correlated with the stability of a gel to shearing. Rigid superabsorbent particles created by increasing the cross-linking can have a high gel modulus and help the particles withstand shearing from the baby's weight.

Although baby diapers are used for a relatively brusque period during the human lifespan, this period of use includes a broad range of developmental progress, from tiny premature babies to toddlers undergoing toilet preparation. Thus diapers for unlike stages of a baby'south development are excellent examples to showcase the application of different technologies used in absorbent hygiene products. To illustrate the result of these stages on product requirements, the differences betwixt products made for three stages are described below.

Newborn phase: In the first three to five months later nativity, parents are peculiarly concerned with protecting their newborn baby's pare and making the transition from the mother'due south womb into the world as smooth and comfortable as possible. Babies in this phase feel the world mainly through feeling and listening, while the visual sense is not nevertheless well developed. Thus, in the diaper context, the tactile properties are particularly important. Diapers for newborns are usually made from peculiarly soft materials, and often feature specific technologies to offer good leakage protection. Equally for any stage, absorption of urine to provide skin dryness and urine leakage protection is important, too.

Determined explorer stage: In this stage babies have become able to walk and are very mobile, so it is important that this mobility is not inhibited by diapers. Diapers for babies in this stage feature not simply good absorbency only besides elastic elements such as stretch sides to accommodate to the baby'due south body during movement, and are made peculiarly thin and narrow between the legs for a good and comfortable fit.

Capable learner phase: Once babies enter the "capable learner" stage, they start to go more contained from the parents and more self-conscious. They endeavour to do many tasks on their own that parents have previously done for them, such every bit trying to dress themselves or taking off/putting on diapers by themselves. Putting on a classical taped diaper without aid is very hard even for a grown-up, and therefore diapers that are shaped similar a pant and can be pulled up are the right choice for babies in this phase.

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