Fluff pulp

The polyacrylate (known as a superabsorbent polymer or SAP by the diaper industry) is distributed throughout the fluff pulp. Another name for these crystals is Waterlock . It is also used for plants to help retain water in the soil. The polyacrylate under pressure can hold an amount of liquid that is as much as thirty times its weight. This correlates to the compression (pressure) that occurs when a baby would sit or lie on the diaper. The polyacrylate allowed the manufacturers to reduce both the weight and thickness of the diaper by 50 percent and increase its absorbency. 

Many other high volume consumer products make use of one or more core layers with absorbent properties. Among the most quickly and highly developed applications are baby diapers, which use super absorbent fibers. Super absorbent polymer (SAP) molecules can trap and hold hundreds to thousands of times their own weight in fluid, ultimately forming a gel. The super absorbent core layer in a diaper is between a non-woven cover stock, a one or two layer non-woven fluff/pulp sheet that takes up, distributes, and draws liquid into the core, and a microporous back sheet. In addition, elastomeric materials and waterproof elements are incorporated. The super absorbent core not only stores liquid but actively pulls moisture out of the damp or even wet fluff/ pulp, thus leaving the contact areas soft and dry. 

In the work from Liu [105], an eco-friendly superabsorbent based on flax yarn waste for sanitary napkin applications has been successfully prepared. Till now, most of the waste cellulose materials from textile industry, such as cotton linter, cotton yarn waste and flax yarn waste, are still burned or land filled, causing both resource waste and environmental pollution [105, 106]. Reutlllzatlon of these waste materials could not only reduce the consumption of cotton or flax cellulose but also decrease the treatment of industrial waste. The major component [70%] of flax yarn waste is cellulose, which has been introduced as a basic skeleton of superabsorbent in previous studies [105, 106-109]. Fluff pulp, as a good absorbent material, is a kind of special pulp with villiform fibers. Nowadays, it is widely used as raw material for the production of sanitary napkin and paper diaper [105]. 

A twin-screw extruder is fed with dry fluff-pulp and the phosphoric acid solvent. The first cooled zone mixes the cellulose into the solvent and reduces the particle size, the second hotter zone starts the dissolution, and the third zone provides further blending and dissolution time, its temperature being controlled to achieve the desired reduction in cellulose DP. A final low pressure zone allows deaeration and dewatering (or the injection of additives) as necessary, and filters remove particles before spinning. 

According to a diaper market sustainability report issued by EDANA, Brussels, Belgium, the average baby diaper is comprised 43% of fluff pulp, 27% SAP, 15% PP, 7% PE, 3% adhesives, and 1% elastics (Edana, 2008). The nonwoven fabric required is of 20—25 g (Pancholi Naik, 2008). Disposable baby diapers were first introduced in the early 1960s, and since then, have been marked by continuous product innovations, including the addition of SAP, resealable tapes, and elasticized waistbands. 

Most diapers currently available are bulk stmctures. A typical diaper is composed of three main components nonwoven layers (top sheet or facing sheet keep the surface dry to facilitate good skin care conditions, back sheet, and distribution layer that prevents leakage and give a cloth-like feel to the external surface), core layer (fluff pulp, tissue, and polymer transfer fluid from the surface, absorb, and hold excretes), and breathable film. Each has a different contribution to the thermal comfort property of the multilayered diaper, (llhan, ingik, im ek, 2015). 

The average sanitary napkin is comprised 48% of fluff pulp 36% PE, PP, and PET 7% adhesives 6% superabsorbent and 3% release paper. Options are available for napkins with fluff, air-laid, or double fluff core, combination with panty liners, additional core or materials, embossing (Brock, 2003), elastic cuffs, with trifolders or single wrappers. Sanitary napkin making machines available in market have production speeds of around 500—1000 pieces per minute. 

AIPs are designated according to the severity of the incontinence problem to be managed as light, moderate, or heavy/double incontinence. Average incontinence product composition, according to ED ANA, is 62% of fluff pulp, 12% SAP, 10% PE film, 15% nonwoven PP, 3% adhesives, and 1% elastics. 

Basic processes in the manufacture of incontinence products are the fiberization of fluff pulp, addition of SAP and absorbent core formation lamination with fills, nonwoven substrates, elastic elements, and tapes printing of wetness indicator and traceability markings and shaping, cutting, folding, and packaging. 

The first commercial production of superabsorbent polymer was began in Japan in 1978, as feminine napkins, using cross-linked starch-grafted polyacryalt. In 1980, superabsorb-ent polymer was used in baby diapers in Germany and France (154). At first, the diapers used only a small amount of superabsorbent polymer as a supplement to fluff pulp that... 

Fluff pulp was used as an absorbent and wet-produced nonwoven cloth was used as the... 

Fluff pulp or crepe pulp was used as the absorbent prior to 1978. Today, materials with a superabsorbent polymer dominate the choice of the material. There are basically two types of absorption layers—either a laminate in which a superabsorbent polymer is sandwiched by a tissue or nonwoven cloth, or a mixture of a superabsorbent polymer and pulp wrapped by a tissue around a nonwoven cloth. In addition, there are variations of these two of absorption layers. For example, a transport layer is introduced between the absorption core and the back panel. Furthermore, a small-sized laminate with a high polymer concentration can be placed on top of the absorption core. The amount of a superabsorbent polymer used for a sanitary napkin is approximately 0.6 to 1.5 g. 

During the production process, SAPs in grannlar or powder forms are added to baby diapers in two ways layered or blended. In the layered method, powdered SAPs are first scattered on a layer of flnff pulp before it is folded, so the SAPs are located in a centralized layer in the absorbent structure, which is further covered with a nonwoven fabric layer. In the blended application, the SAPs are first mixed homogeneously with the fluff pulp before the mixture is laid down to form the absorbent structure, which is subsequently covered with a nonwoven fabric. 

The fluid absorption of Super Absorbent Polymers was found to be less when incorporated into fluff pulp air formed fleeces, found in hygienic disposables, than their absorption in pure form. This difference was attributed to a competition for available fluid between the SAP and the capillary forces in the pores of the fluff pulp structure. Absorption of an ionic Acrylate base and a non-ionic PVA base SAP was compared in laboratory tests in pure form and in air formed felts, then in use tests in baby diapers. Diapers performance did not correlate with the laboratory tests. The difference was related to the quantity of fluid available in the tests. 

Super absorbent polymers (SAP) have enjoyed rapid sales growth in disposable baby diapers because of their high absorptivity of water systems of low ionic strength. This application was selected for study because SAP s are now used in approximately 90% of the 19 billion disposable baby diapers produced annually ion the United States. However, the absorptivity of SAP s in pure form in laboratory tests is far greater than that observed when they are incorporated not the cellulose fluff pulp used in a diaper core. 

The purpose of this paper is to explain these differences and to suggest that absorption of fluid and fluid retention under load in a fluff pulp-SAP system is a complex function of system density and the concentration of the SAP present. 

The technique used to measure absorptive properties of fluff pulp systems containing different super absorbents was to perform multivariate experiments (of the Box Wilson type [1]) and fit a quadratic regression equation in the parameters studied. This procedure reduces the danger of drawing conclusions that are valid for only a narrow set of conditions which can occur when univariate experimental methods are used. 

The test pads contained, in addition to fluff pulp and SAP, PulPlus , a polyethylene pulp. The PulPlus pulp was included so that the test specimens could be thermally bonded. The density of each pad was controlled by fusing the specimens in a press at fixed caliper. The virtue of using bonded pads is that they undergo negligible distortion during handling in the dry state and while being wet out, and the effect of density on absorption properties can be more precisely determined. 

Table 1 shows that the ACI values of unbonded diaper cores with and without a commercial acrylate polymer. Assuming the absorption effects of a fluff pulp and the SAP are additive, the SAP contribution Is 28 g/g for the GATS ACI value and 24 g/g retention at 3.5 kPa load. This same SAP measured 60 g/g in pure form in 0.9% saline. 

Table 2 Laboratory Absorption and Retention of Fluff Pulp Pads as a Function of SAP Type ...

Thus, in a fluff pulp system whose compressive modulus is increased by means of thermal bonding, the mode of fluid retention shifts with composition. 

Although the cellulose attractive force for water Is high, the amount picked up is modest. Water imbibed by native cellulose fibers is 40 % [5]. In a thermally bonded fluff pulp system containing little or no SAP, retention is Increased by increasing the density level. Under these conditions the capillary forces in the pores are high. The structure is relatively rigid and resists compression and loss of fluid because there are a large number of bond points per unit volume. 

Ionic Strength of Saline in Fluff Pulp Cores by Atomic Absorption of Na... 

SAP crosslinking did not greatly Influence the results. One explanation is that the thermal bonding created fluff pulp structures that were sufficiently resistant to compression that high SAP crosslink levels were not required for good fluid retention. 

SAP performance in diaper cores in standard laboratory absorption tests did not correlate with end use performance because fluid loading in actual use is much less than in laboratory test procedures. A multivariate experiment with a thermally bonded fluff pulp system containing SAP showed that the mode of fluid absorption and retention shifted as the system density and SAP concentrations were changed. Maximum retention was achieved at low fluff density and high SAP concentration. 

Uses Used for quick interruption of debonding effect of cationic debonders in production of fluff pulp Berocell 582 [EkaChems]... 

Uses Surfactant, debonder, mullen restorer in fluff pulp mfg. 

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