Yarn Preparation

The main component of warp size is usually starch, polyvinyl alcohol (PVOH) or a blend of the two. Other size materials are sometimes used commercially to a lesser extent. These other, less often used types, include derivatized natural sizes and synthetic sizes listed in Table 7.12. In addition to the main size components 

Derivatized Natural Sizes Carbox3methyl cellulose (CMC), Hydroxyethyl cellulose (HEC) 

Adhesives and binders Natural gums (locust bean gum, tragasol) 

Antisticking agents, to reduce fouling of equipment Waxes Mineral oils Sulfated tallow Pine oil Kerosene Stoddard solvent 

Biocides and mildew inhibitors, to improve shelf life of woven goods Orthophenyl phenol (OPP) 

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The removal of fiber/yarn preparation during the pretreatment of knitted material can be identified as an important source of oil, grease, and silicones in wastewater. A general treatment can be performed by means of precipitation, flocculation, membrane filtration, and evaporation. 

Various 66 polyamide continuous yarns were also examined (referred to as, "type 2", "type 4" and "type 5") these are experimental yarns prepared in different conditions and supplied by RPT. 

Muff n. A loose skein of textured yarn prepared for dyeing or bulking. In the bulking operation, the yarn contracts and the resulting skein resembles a muff. 

Wang X, Zhang K, Zbu M, Yu H, Zhou Z, Chen Y and Hsiao B S (2008) Continuous polymer nanofiber yarns prepared by self-bundling electrospinning method, Po/ /mer 49 2755-2761. 

The economics of recovery are a very strong function of the amount of zinc used in the preparation of the yarn and the ratio of acid to zinc in the spinning bath. In manufacturing industrial yarns and tire cords, it is common to use 4.5 to 7.5 kg of zinc per 100 kg of yam. This high concentration of zinc makes recovery extremely attractive. Textile yams use less zinc, and although recovery is still the most economic solution, it offers less of a return. These two cases are presented as extremes, with many plants falling between the two values. 

The poly(ethylene terephthalate-co-esters) were prepared as previously described (9) after knitting, scouring, and deknitting, the yarns were examined, tested and exposed in a standard fashion (9) to 3000 A radiation. 

GNB remain on the lint (97.2% of raw cotton weight), simple calculations show that only about 56% of the total GNB content in raw cotton is localized on the gross trash. Removal of all gross trash from raw cotton will still leave about 44% of the GNB on the lint or on the fine particulate associated with the lint. Thus, extensive cleaning of these raw cottons either in the gin or in the preparative steps of cotton yarn production might not significantly lower the content of entrained GNB. 

The process for sheepskin is rather more gentle in order to avoid damage to top quiity wool that can be spun into valuable wool yarn. Liquid protease preparations such as pancreatic extracts of trypsin and chymotrypsin are applied to the flesh side of the sheepskin. The proteases diffuse to the basal papilla of the hair follicle, and subsequent protein breakdown releases the wool hair with minimal damage 34),... 

Bundle Preparation. Packages of multifileiment yarns are backwound to prepare bundles necessary for the manufacture of a reverse osmosis module. A proprietary winder for this operation has been designed and constructed at Albany International Research Co. This device is capable of helically winding multifilament yarns into bundles around a mandrel. This is done in a manner such that the resulting bundle has uniform cylindrical dimensions and uniform fiber density. This minimizes channeling and optimizes exposure of membrane surface area. 

Research effort at Albany International Research Co. has developed unit processes necessary for pilot scale production of several species of reverse osmosis hollow fiber composite membranes. These processes include spin-dope preparation, a proprietary apparatus for dry-jet wet-spinning of microporous polysul-fone hollow fibers, coating of these fibers with a variety of permselective materials, bundle winding using multifilament yarns and module assembly. Modules of the membrane identified as Quantro II are in field trial against brackish and seawater feeds. Brackish water rejections of 94+% at a flux of 5-7 gfd at 400 psi have been measured. Seawater rejections of 99+% at 1-2 gfd at 1000 psi have been measured. Membrane use requires sealing of some portion of the fiber bundle for installation in a pressure shell. Much effort has been devoted to identification of potting materials which exhibit satisfactory adhesion to the fiber while... 

Najera, C. Lifhiated /Yarn i rioalkyl sulfones as mono and dinudeophiles in the preparation of nitrogen heterocydes application to the synthesis of capsazepine. Tetrahedron 1997,... 

The materials used included dyed and undyed yarn and fiber samples obtained from the manufacturers and fabric and other polymeric materials from the marketplace. The samples were encapsulated without preparation and the experimental conditions are noted on each figure. Unless otherwise noted, the DSC samples were run in an atmosphere of dry nitrogen. 

Substrate and its Preparation. The substrate used for grafting purpose were jute fiber (defatted and bleached) and KPM rayon yarn. Jute fiber under investigation was of Corchorus Capsularis variety. It was arbitrarily divided into three portions. The middle portion was chosen for the purpose of study. 

Researchers in the Lille group have also been successful in preparing yarns from polypropyl-ene/multiwalled carbon nanotubes (MWNT) (1% and 2% by mass) nanocomposites.6-86 Fabrics knitted from these yarns were tested by cone calorimetry. PHRR reduced by 50% for a fraction of nanotubes of only 1 wt % but the TTI of the nanocomposite was shorter. This is shown in Figure 24.9. 

A pilot plant scale starch solution, approximately 300 l, was prepared in a stainless steel container equipped with a paddle wheel electric stirrer, steam-heated coils, steam injection, an external gear pump with recirculation capability, insulation surrounding the container, a container lid, and a vent. The starch solution was prepared with the same percentage composition and duration of heating as described for the laboratory scale process. The first batch was pimped into the "sizing box" of the slasher and utilized immediately hot as a conventional yarn treatment. 

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