Synthetic fabrics

The Bucher-Guyer horizontal rotary press is a highly automated batch process machine that requires no press aid. The press consists of a horizontal hydrauhc ram inside a rotating cylinder containing many flexible rods covered with a knitted synthetic fabric. The rods have serrated surfaces to allow juice which passes through the fabric to flow to the discharge ends. Hydrauhc pressure is apphed for a preset time, the ram is retracted, and the cylinder is rotated to break up the press cake. This cycle is repeated several times before the press cake is removed from the cylinder and the press is cleaned (16). Juice yield for this horizontal rotary press is 84% with secondary water addition it is increased to 92% (15). 

Leather-like materials now important in the market are of three main classes (/) vinyl-coated fabrics, (2) urethane-coated (synthetic) fabrics, and (J) man-made leathers. To appreciate their leather-replacement capabiUties it is necessary to know the stmcture of natural leather. 

The solution (pad bath) contains one or more of the amino resias described above, a catalyst, and other additives such as a softener, a stiffening agent, or a water repeUant. The catalyst may be an ammonium or metal salt, eg, magnesium chloride or ziac nitrate. Synthetic fabrics, such as nylon or polyester, are treated with amino resias to obtaia a stiff finish. Cotton (qv) or rayon fabrics or blends with synthetic fibers are treated with amino resias to obtain shrinkage control and a durable-press finish. 

Synthetic fabrics can also be finished to achieve a number of specific characteristics (199). For example, increased electrical conductivity can improve the antistatic character of polyester. Similarly, finishes that improve hydrophilic character also improve properties related to soil release and soil redeposition (199,200). 

N,]Sf -DicHoiocaibodiimide is useful ia preparation of photothermographic materials (101). Chlorinated guanylurea (av CI2 85%), prepared from dicyanamide, is useful as a bleach for synthetic fabrics (102). Chlorazodin, dichloroa2odicarbonarnidine, NH2C(=NC1) N=NC(=NC1) NH2, [502-98-7]... 

Antiredeposition agents contribute to the appearance of washed fabrics. Sodium carboxymethylceUulose [9004-32-4], NaCMC is the most widely used, and on cotton fabrics, the most effective. With the advent of synthetic fabrics, other cellulose derivatives, eg, methylceUulose [9004-67-5], hydroxybutjiceUulose, hydroxypropyl- and mixed methyl and hydroxybutyceUulose ethers have been shown to be more effective than NaCMC (8) (see... 

Polyester fabrics and many other hydrophobic synthetic fabrics require the appHcation of an antistatic agent prior to printing to prevent the buildup of static charges at rapid printing speeds (see Antistatic agents). 

Commercially available membranes are usually reinforced with woven, synthetic fabrics to improve the mechanical properties. Several hundred thousand square meters of IX membranes are now produced aimuaHy, and the mechanical and electrochemical properties are varied by the manufacturers to suit the proposed appHcations. The electrochemical properties of most importance for ED are (/) the electrical resistance per unit area of membrane (2) the ion transport number, related to current efficiency (2) the electrical water transport, related to process efficiency and (4) the back-diffusion, also related to process efficiency. 

Industrial filtration systems may be of many types. The most common type is the baghouse shown in Fig. 29-3. The filter bags are fabricated from woven material, with the material and weave selected to fit the specific application. Cotton and synthetic fabrics are used for relatively low temperatures, and glass cloth fabrics can be used for elevated temperatures, up to 290 C. 

In applications where the filter aid layer is to be formed on open-weave synthetic fabric or wire screens, wider size distributions may have to be... 

A safety shower is required whenever there is even the slightest possibility that clothing could catch fire or where hazardous chemicals could be spilled on skin or clothing. The use of safety blankets, though still available, is no longer recommended by some safety experts. The synthetic fabrics used in today s clothing, they claim, can melt from the heat and stick to the skin, thereby creating a secondary problem. In case of spills, of course, blankets are of no use. 

As discussed in Chapter 10, a wide variety of additives is used in the polymer industry. Stabilizers, waxes, and processing aids reduce degradation of the polymer during processing and use. Dyes and pigments provide the many hues that we observe in synthetic fabrics and molded articles, such as household containers and toys. Functional additives, such as glass fibers, carbon black, and metakaolins can improve dimensional stability, modulus, conductivity, or electrical resistivity of the polymer. Fillers can reduce the cost of the final part by replacing expensive resins with inexpensive materials such as wood flour and calcium carbonate. The additives chosen will depend on the properties desired. 

Polyesters, which are a class of engineering thermoplastics, are found in a wide variety of applications including carbonated drink bottles, fibers for synthetic fabrics, thin films for photographic films and food packaging, injection molded automotive parts, and housings for small appliances. In this chapter, we svill explore the synthesis of this class of polymers. We will also look at the typical properties and end uses for the most common of these resins, polyethylene terephthalate and polybutylene terephthalate, which are commonly known as PET and PBT, respectively. 

In 1932, nine out of ten kilos of textiles the Germans used had been imported. This ratio applied to most other household things. Farben went into the forests. Soon every other citizen arose to the tinkle of a Farben plastic clock, rolled back a new synthetic-fabric spread. Every other man shaved with Farben soap that had been made from the residue of the paraffin that had been made from the coal. At least twice a week, the German ate a new Farben food cooked in synthetic fat. Six out of ten dinner tables were spread with Farben cloths. After the worker went to his job, his wife cleaned the linen, the curtains, the casements, and dusted the furniture goods — all made from beechwood. 

Cyanides are used widely and extensively in the manufacture of synthetic fabrics and plastics, in electroplating baths and metal mining operations, as pesticidal agents and intermediates in agricultural chemical production, and in predator control devices. Elevated cyanide levels are normally encountered in more than 1000 species of food plants and forage crops, and this probably... 

The formula of acrylonitrile which is a basic material in the production of synthetic fabrics is given below ... 

Macromolecules are found in nature. Cellulose, wool, starch, and DNA are but a few of the macromolecules that occur naturally. Carbons ability to form these large, complex molecules is necessary to provide the diversity of compounds needed to make up a tree or a human being. But many of the useful macromolecules that we use every day are created in the lab and industrial complex by chemists. Nylon, rayon, polyethylene, and polyvinyl chloride are all synthetic macromolecules. They differ by which repeating units (monomers) are joined together in the polymerization process. Our society has grown to depend on these plastics, these synthetic fabrics. The complexity of carbon compounds is reflected in the complexity of our modern society. 

Some polymers, both synthetic and natural, can be spun into long, thin fibres. These fibres are woven into natural fabrics (such as cotton, linen, and wool) or synthetic fabrics (such as rayon, nylon, and polyester). Figure 2.11, on the next page, shows some polymer products. 

With the current energy conscience of the consumer market and increasing use of synthetic fabrics, laundry washing at lower temperatures is becoming more... 

The rubber stock, once compounded and mixed, must be molded or transformed into the form of one of the final parts of the tire. This consists of several parallel processes by which the sheeted rubber and other raw materials, such as cord and fabric, are made into the following basic tire components tire beads, tire treads, tire cords, and the tire belts (fabric). Tire beads are coated wires inserted in the pneumatic tire at the point where the tire meets the wheel rim (on which it is mounted) they ensure a seal between the rim and the tire. The tire treads are the part of the tire that meets the road surface their design and composition depend on the use of the tire. Tire cords are woven synthetic fabrics (rayon, nylon, polyester) impregnated with rubber they are the body of the tire and supply it with most of its strength. Tire belts stabilize the tires and prevent the lateral scrubbing or wiping action that causes tread wear. 

After the fabric is clean, special brighteners (fluorescent substances) can be applied that give a bluish haze to the fabric. This enhances the whiteness (by depressing the yellow tinge). Additionally, these also enhance the color perception. Brighteners as used for cotton are different from those used for synthetic fabrics. 

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