Launder

Borax is used in the production of pyrex glass, ceramics, as a flux in soldering and welding, and in laundering to impart a glaze to linen. 

Laudanum Laumontite Laundering fastness Launder-ometer test Laundries Laundry bleaches Laundry bluing Laundry cleaners Laundry products Laundry sour Laur amide... 

Oil-free alkyds Oil from seeds Oil-in-water emulsion Oil laundering Oil length Oil mining Oil of anise Oil of bergamot Oil of eucalyptus Oil oflemon Oil of Olay Oil of Palma Christi Oil of turpentine Oil Orange Oil-pump Oil reclaiming Oil recovery... 

The mechanical properties of acryUc and modacryUc fibers are retained very well under wet conditions. This makes these fibers well suited to the stresses of textile processing. Shape retention and maintenance of original bulk in home laundering cycles are also good. Typical stress—strain curves for acryhc and modacryUc fibers are compared with wool, cotton, and the other synthetic fibers in Figure 2. 

Improved Hot—Wet Properties. Acryhc fibers tend to lose modulus under hot—wet conditions. Knits and woven fabrics tend to lose their bulk and shape in dyeing and, to a more limited extent, in washing and drying cycles as well as in high humidity weather. Moisture lowers the glass-transition temperature T of acrylonitrile copolymers and, therefore, crimp is lost when the yam is exposed to conditions requited for dyeing and laundering. 

The wet modulus of fibers at various temperatures influences the creasing and mussiness caused by laundering. Figure 6 shows the change with temperature of the wet modulus of acetate and triacetate, and compares them with a number of other fibers (2). Acetate, triacetate, and rayon behave quite similarly, with a lower sensitivity than acryUc. 

Chemical Properties. Under slightly acidic or basic conditions at room temperature, acetate and triacetate fibers are resistant to chlorine bleach at the concentrations normally used in laundering. 

Despite the anhydride stmcture, it is remarkably stable, surviving addition to the highly alkaline viscose, the acidic coagulating bath, and also resisting multiple laundering of the rayon fabric. The unusual stability may be attributed to the sulfur atoms, which enhance hydrophobicity, and to the stericaHy hindering neopentyl groups that retard hydrolysis. 

Pyrovatex CP coreacts on cellulose with an amino resin in the presence of a latent acid catalyst, to produce finishes durable to laundering (125,126). A higher assay version, Pyrovatex (CP New, has also been introduced. 

Oligomeric Vinylphosphonate. A water-soluble oligomer, Fyrol 76 [41222-33-7] is produced by reaction of bis(2-chloroethyl) vinylphosphonate and dimethyl methylphosphonate with elimination of all the chlorine as methyl chloride (127,128). This Hquid, containing 22.5% P, is curable by free-radical initiation, on cotton or other fabrics. Nitrogen components, such as A/-methylolacrylamide or methylolmelamines, are usually included in the finish, which can be durable to multiple launderings (129,130). 

The first known fire-retardant process found durable to laundering was developed in 1912 (4). A modification of an earlier process (5), this finish was based on the formation of a tin(IV) oxide [18282-10-5] deposit. Although the fabric resulting from treatment was flame resistant, afterglow was reputed to be a serious problem, resulting in the complete combustion of the treated material through smoldering. 

Phosphorylated cottons are flame resistant ia the form of the free acid or the ammonium salt. Siace these fabrics have ion-exchange properties, conversion to the sodium salt takes place readily during laundering if basic tap water is used. However, flame resistance can be restored if the fabric is treated with either acetic acid [1563-80-8] or ammonium hydroxide [1336-21 -6] after washing. 

Dialkylphosphonopropionamides. CeUulosic derivatives that closely resemble those based on the dialkylphosphonopropionamides have been prepared (71). The fabric was treated with AJ-hydrox raethylhaloacetamides (chloro, bromo, or iodo) in DME solution by a pad-dry-cure technique with a 2inc nitrate [10196-18-6] catalyst. It was then allowed to react in solution with trimethyl phosphite [121 -45-9] at about 140—150°C the reaction rates decreased in the order iodo > bromo > chloro. With phosphoms contents above 1.5%, good flame resistance, durable to laundering, was obtained without noticeable loss in fabric strength. 

The tetramethylol derivative of DABT, prepared by reaction of DABT with alkaline aqueous formaldehyde, polymerized readily on cotton. It imparted excellent flame retardancy, very durable to laundering with carbonate- or phosphate-based detergents as well as to hypochlorite bleach. This was accomphshed at low add-on without use of phosphoms compounds or antimony(III) oxide (75—77). 

THPC—Amide Process. The THPC—amide process is the first practical process based on THPC. It consists of a combination of THPC, TMM, and urea. In this process, there is the potential of polymer formation by THPC, melamine, and urea. There may also be some limited cross-linking between cellulose and the TMM system. The formulation also includes triethanolamine [102-71-6J, an acid scavenger, which slows polymerization at room temperature. Urea and triethanolamine react with the hydrochloric acid produced in the polymerization reaction, thus preventing acid damage to the fabric. This finish with suitable add-on passes the standard vertical flame test after repeated laundering (80). 

Another modification of this process was reported in 1988 (84). In this process, a precondensate of THPC and urea, plus excess urea, are neutralized to a pH of about 5.7, and the buffer salt is added. The fabric is then given a standard pad-dry-cure process followed by oxidation and laundering. The principal advantage of this modification is a reduction in both formaldehyde vapors and phosphine-like odors released during processing (84). 

Ammonia—Gas-Cured Flame Retardants. The first flame-retardant process based on curing with ammonia gas, ie, THPC—amide—NH, consisted of padding cotton with a solution containing THPC, TMM, and urea. The fabric was dried and then cured with either gaseous ammonia or ammonium hydroxide (96). There was Httle or no reaction with cellulose. A very stable polymer was deposited in situ in the cellulose matrix. Because the fire-retardant finish did not actually react with the cellulose matrix, there was generally Httle loss in fabric strength. However, the finish was very effective and quite durable to laundering. 

The two-equation model of Launder and co-workers (22,23) and the one most often used employs the S equation given by... 

B. E. Launder and D. B. Spalding, Mathematical Models of Turbulence, Academic Press, Inc., New York, 1972. 

Detergent Applications. The primary function of FWAs in the laundry process is to whiten fabric load and maintain the original appearance of the white, laundered articles. Laundering is characterized by repeated appHcation to the same item. Fluorescent whiteners used in this repetitive process have to compensate for the reduction in whiteness and contribute toward prolongation of the usefiil life of the textile material. 

Control of Souring Operations, Special Keport 7, American Institute of Laundering, JoHet, HI. 

Isasmelt bath Patch process ak-cooled lance from top oxidation and reduction vessels connected by a launder... 

The high lead slag from the smelting furnace is tapped continuously and transferred down a heated launder directly into the reduction furnace through a port in the side of the vessel. Lump coal for reduction is fed continuously to the furnace by conveyor and dropped direcdy into the bath. Heating for the endothermic reduction reactions is provided by oil injected down the lance. The combustion air stoichiometry is set at 95% of that required for complete oil combustion. Air is injected into the top of the furnace to afterbum the volatile materials from the coal and provide additional heat to the top of the furnace. Reduction temperatures range from 1170 to 1200°C to maintain slag duidity. 

The success of the process results from the fact that nowhere inside the furnace is heat extracted from the copper-saturated blast furnace buUion through a soUd surface. The problem of accretion formation (metal buUd-up), which has plagued many other attempts to estabUsh a copper dtossing operation of this type, does not arise. In the cooling launder, lead-rich matte and slag accumulate on the water-cooled plates, but these ate designed so that when they ate lifted from the buUion stream, the dross cracks off and is swept into the furnace via the cooled lead pot. 

The lead contains residual calcium and magnesium that must be removed by chlorination or treatment with caustic and niter. The molten lead is pumped or laundered to the casting kettles in which it is again treated with caustic and niter prior to mol ding, After a final drossing, the refined lead is cast into 45-kg pigs or 1- and 2-t blocks. 

Coverahs or other full-body clothing should be worn when working with lead ahoys and properly laundered after use. Hard hats, safety glasses, safety boots, and other safety equipment should be worn as appropriate for the industrial environment where the lead ahoys are used. Hands, face, neck, and arms should be washed before eating or smoking. 

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