Finishing applications

It is used in adhesives, paper coating and sizing, and textile warp size and finishing applications. 

Ultrafiltration membranes are commercially fabricated in sheet, capillary and tubular forms. The liquid to be filtered is forced into the assemblage and dilute permeate passes perpendicularly through the membrane while concentrate passes out the end of the media. This technology is useful for the recovery and recycle of suspended solids and macromolecules. Excellent results have been achieved in textile finishing applications and other situations where neither entrained solids that could clog the filter nor dissolved ions that would pass through are present. Membrane life can be affected by temperature, pH, and fouling. 

Fiber filaments, crystalline and amorphous regions in, 24 613 Fiber finishes, 19 755-756 20 17 Fiber finishing applications, of silicones, 22 592-594... 

The cost for companies in terms of cash, possibly scarce water resources, ever tightening discharge limitations and perpetual liability for landfilled waste, requires that firms seek other solutions. The ideal solution is to develop economic point of use recycling and reuse systems. A technology that offers the potential for on-site recovery of a broad range of electronics and metal finishing applications is Advanced Reverse Osmosis (ARO). 

Many of the finishes applied to other types of metal products can also be applied to zinc die castings, although some differences in formulation as well as occasional differences in method of application may be desirable. The types of finishes applicable to zinc die castings include mechanical finishes (buffed, polished, brushed, and tumbled) electrodeposited finishes (copper, nickel, chromium, brass, silver, and black nickel) chemical finishes (chromale, phosphate, molybdate and black nickel) and organic finishes (enamel, lacquer, paint and varnish, and plastic finishes). Electrodeposited coatings of virtually any metal capable of electrodeposition can be applied to zinc die castings. 

The CAV for a particular process is dependent on fibre type and fabric construction and absorbency. A finish application below the CAV may result in a non-uniform speckled treatment, while an application above the CAV could lead to finish migration. Cellulosic fibres, becanse of their inherent hydrophilicity, have CAVs in the range of 35 0 % wet pickup. Hydrophobic fibres like polyester can have CAVs of less than 5 %, allowing much lower wet pickups than hydrophilic fibres. 

There are two main types of low wet picknp applicators. The first is the saturation-removal type where the fabric is completely satnrated with the finish liquid and then the excess liqnid is removed mechanically or with a vacnnm before drying. With the second type, a precise amount of finish liqnid is nniformly applied to the fabric using transfer roll, spray or foam techniqnes. Table 2.2 gives a snrvey on low wet pickup finishing application methods, some of which will now be discussed in more detail. 

Table 2.2 Low wet pickup finish application methods (adapted from Greenwood and Holme) ...

In all these application methods, proper fabric preparation is required in order to achieve uniform finish distributions. A well-absorbent fabric is the best guarantee of a proper finish application. 

A third approach to the application of insect resist finishes is to combine the finish with spinning lubricants and then to apply the combination to loose wool prior to spinning. This method of finish application produces yams with only a superficial treatment with much lower fastness than applications made during dyeing or scouring. 

Low concentrations applied in the last rinse after dyeing improves stretchability and softness without reducing fabric absorbency and thereby effecting the percent pick-up of subsequent finish applications. 

Dyebath softener/lubrlcants. Offer excellent compatibility in dyeing system. Permits single-bath dye and finish applications. ... 

Because of the specific hand effects resulting from the use of silicone fluid emulsions, silicones find a wide range of application as softening agents in textile finishing. Application is almost exclusively from the aqueous phase. 

The chemicals may constitute a substantial portion of the finished textile. In many cases 10% or more of the fabric s final weight may derive from textile chemicals added to improve or enhance one or another of the fabric s properties. Representative raw materials employed for textile finishing applications are fatty alcohol ether sulfates, vinyl acetate-ethylene copolymers, hydrated alumina, alkylolamides, alkoxylates, chlorinated paraffins, alginates, sodium tripolyphosphates, sorbitan fatty acid esters, ethoxylated triglycerides, and silicones. 

Provisions of the Clean Ait Act have resulted in the regulation of certain wood finishing applications. Residential and Institutional Furniture and Kitchen Cabinet Industries are under regulations which specify the amount and types of solvent emissions allowed. The size and location of a finishing facility determine the extent of the effect stemming from the regulations. 

The most-used silicone lubricants in the fibre finishing applications are polydimethylsiloxane, polymethylphenylsiloxane, oleophilic silicone/organic copolymer (Fig. 5.7a), and poly(glycol silicone copolymer) (Fig. 5.7b). The analysis of silicones can be conducted by FTIR. A strong and often broad absorption in the 1000-1100 cm region can be attributed to the Si-O vibration. A peak at 1100 cm shows the Si-O-Si vibration. A sharp peak at 1260 cm" indicates the Si-( II. stretching absorption.- ... 

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