Nylon powder

In 1954 the surface fluorination of polyethylene sheets by using a soHd CO2 cooled heat sink was patented (44). Later patents covered the fluorination of PVC (45) and polyethylene bottles (46). Studies of surface fluorination of polymer films have been reported (47). The fluorination of polyethylene powder was described (48) as a fiery intense reaction, which was finally controlled by dilution with an inert gas at reduced pressures. Direct fluorination of polymers was achieved in 1970 (8,49). More recently, surface fluorinations of poly(vinyl fluoride), polycarbonates, polystyrene, and poly(methyl methacrylate), and the surface fluorination of containers have been described (50,51). Partially fluorinated poly(ethylene terephthalate) and polyamides such as nylon have excellent soil release properties as well as high wettabiUty (52,53). The most advanced direct fluorination technology in the area of single-compound synthesis and synthesis of high performance fluids is currently practiced by 3M Co. of St. Paul, Minnesota, and by Exfluor Research Corp. of Austin, Texas.  [c.278]

Tent Fumigation. Citms and deciduous fmit trees have been fumigated for the control of scale insects for many years by hydrogen cyanide introduced under relatively gastight tents of 240 270 g/m (7-8 oz/yd ) army duck or nylon impregnated with vinyl chloride—vinyl acetate copolymer. Methyl bromide fumigation of buildings for the control of termites or powder post beetles, of mills or warehouses, or of bagged commodities for the control of stored-product insect pests, is effected by wrapping the stmcture in polyethylene or poly(vinyl chloride) plastic sheeting that is 0.102—0.152 mm thick, roUed and clamped at the edges, and sealed at the bottom by soil or sand bags.  [c.299]

PVB dispersions are widely used in the textile industry to impart abrasion resistance, durabiUty, and fiber strength. They have been used for finishing nylon webbing for parachute harnesses and seat belts. They can be appHed to textiles by spraying, from a dilute bath by impregnation on a padder, or from a thickened dispersion by coating on spreading equipment. The dried dispersion imparts a soft, hiU-bodied finish to rayon, cotton, or nylon and helps prevent raveling of filament yams. PVB dispersions have been used to finish curtain and drapery fabrics and upholstery goods, to join fabric to fabric and other materials, and as a component in transparent mg backings.  [c.454]

For maximum performance, a primer is used. Most nylon primers are unpigmented resin solutions appHed at only ca 10% soHds. This gives a dry film thickness of about 3—5 p.m. If nylon is appHed by electrostatic spray techniques, it is necessary to prime the parts. Although the exact reason is not known, it is speculated that either the primer partially insulates the coating from the substrate and prevents the charge in the electrostatically appHed powder layer from leaking off too quickly, or the primer is tacky at the fusion temperature and causes the coating to adhere to the substrate. Nylon coating powders are discussed in more detail in Reference 6.  [c.319]

Nylon 11 is also used in powder form in spraying and fluidised bed dipping to produce chemical-resistant coatings. Although more expensive than the polyolefin and PVC powders, it is of interest because of its hardness, abrasion resistance and petrol resistance.  [c.504]

Epoxide resins are available in a powder form that contains a suitable hardening system. The powder may be used for coating metals by fluidised bed or by electrostatic spraying techniques. Unlike with nylon and polyolefin powder coatings it is necessary to bake the coating in order to cure the resin. The powder coating are particularly useful for application of thick film to parts of a complicated or irregular shape and have good chemical and electrical resistance. The coatings are much harder and adhere more strongly to the substrate than the older more well-established thermoplastic powders. The electrostatic spraying of epoxide powders to form surface coatings presents an important challenge to the usual methods using solutions.  [c.776]

Plastics used for fluidised bed powder coatings include polyethylene, p.v.c., nylon, p.v.f.2, p.e.c.t.f.e. and a variety of polyolefins and their copolymers.  [c.748]

Most thermoplastics are not suitable for spraying because they are too tough. If they were brittle enough to be economically ground to the required fine particle size the physical properties of the coating would be poor. Also, for optimum charge retention the volume resistivity of the powder should be at least 10" Most thermoplastics fall below this. However, Nylon 11 powders are available for general use and p.v.c. powders are used for coating continuous galvanised wire mesh for fencing.  [c.748]

Powder Coating. Nylon-11 and nylon-12 are used in powder form for anticorrosion coating of metals. Dip coating and electrostatic and flame spraying are used. Dip coating, which involves immersing a preheated article into fluidi2ed nylon powder, is most suitable for automation.  [c.274]

Nylon powder. Pellets were dissolved in ethylene glycol under reflux. Then ppted as a white powder on addition of EtOH at room temperature. This was washed with EtOH and dried at 100° under vacuum.  [c.316]

Rotomolding. Nylon-6, nylon-11, and nylon-12 can be used in rotomolding and are generally suppHed for these appHcations as a powder or with a small pellet si2e. The process involves tumbling the resin in a heated mold to form large, thin-walled mol dings. Nylon-11 and nylon-12 use mold temperatures of 230—280°C and nylon-6 is processed at over 300°C. An inert gas atmosphere is preferred to avoid oxidation.  [c.274]

The positive plates are siatered silver on a silver grid and the negative plates are fabricated from a mixture of cadmium oxide powder, silver powder, and a binder pressed onto a silver grid. The main separator is four or five layers of cellophane with one or two layers of woven nylon on the positive plate. The electrolyte is aqeous KOH, 50 wt %. In the aerospace appHcations, the plastic cases were encapsulated in epoxy resins. Most usehil cell sizes have ranged from 3 to 15 A-h, but small (0.1 A-h) and large (300 A-h) sizes have been evaluated. Energy densities of sealed batteries are 26-31 W-h/kg.  [c.557]

The use of nylon-11 for powder coatings or dry coatings (qv) has been developed in response to a growing concern for the environment (44) (see Coating PROCESSES, powder technology). Electrostatic deposition allows thin films to be appHed to metal substrates. Once the powder is appHed, it must be melted and coalesced into a continuous plastic film. Eorced draft or irradiant ovens are used for fusion, and because no polymerization or cross-linkage are required for curing, coated objects can be processed quickly and air-cooled (45).  [c.154]

Polyamides. Nylon-11, accounts for the largest single use of castor oil. Pyrolysis of the oil yields methyl undecylenate, which is converted to 11-amino-undecanoic acid. Condensation of this monomer produces nylon-11, known commercially as KUsan 11 (Atochem, Inc.). Nylon-11 is used as an engineering plastic in the automotive and transport industry in the form of fuel lines. Products are also used for extmded and molded components of fuel systems such as filler necks, gas tanks, reservoir modules, filters, fuel rads, and vapor recovery systems. Air brake hoses on large trader tmck transports are made of nylon-11, and nylon-11 tubing is used in the compressed air industry in pneumatic control systems. In addition, nylon-11 is used in powder coatings to coat metals that require abrasion, impact, and corrosion resistance. Nylon-11 offers high dimensional stabdity, close mol ding tolerance, high abrasion and impact resistance, excellent dielectric strength, low moisture absorption, electrical insulating properties, and overall chemical resistance and durabdity (45,70).  [c.156]

In the case of gases, flow lines can be revealed through the use of smoke trac-es or the addition of a hghtweight powder such as balsa dust to the stream. One of the best smoke generators is the reac-tion of titanium tetrachloride with moisture in the air. A woodsmoke-generation system is described by Yu, Sparrow, and Eckert [Int. J. Heat Mass Transfer, 15, 557-558 (1972)]. Tufts of wool or nylon attached at one end to a sohd surface can be used to reveal flow phenomena in the vicinity of the surface. Optical methods commonly employed depend upon changes in the refractive index resulting from the presence of heated wires or secondaiy streams in the flow field or upon changes in density in the primaiy gas as a result of compressibility effects. The three common techniques are the shadowgraph, the schlieren, and the interferometer. All three theoretically can give quantitative information on the velocity profiles in a two-dimensional system, but in practice only the interferometer is commonly so used. The optical methods are described by Ladenburg et al. (op. cit., pp. 3-108). For additional information on other methods, see Goldstein, Modern Developments in Fluid Dynamics, vol. 1, London, 1938, pp. 280-296.  [c.889]

See pages that mention the term Nylon powder : [c.377]    [c.219]   
Purification of laboratory chemicals (2003) -- [ c.316 ]