Vinyl resins application techniques

The increased solubility of vinyl polymers in solvents at elevated temperatures enables very high solids to be obtained for application techniques like hot airless spraying or curtain coating. Figure 33 illustrates this property with a vinyl chloride-trifluorochloroethylene copolymer at 25° to 95°C. Since the solubility of the resin improves with... 

Thermoplastic resins, such as vinyl chlorides, vinyl acetates and polyamides are employed, particularly in the water industry, on buried pipes and fittings. To provide both internal and external coating, application may be by one of these principle techniques dipping in a plastisol, fluidised beds or electrostatic spray. 

Vinylidene chloride-vinyl chloride copolymers were originally developed for thermoplastic molding applications, and small amounts are still used for this purpose. Extrusion of VDC-VC copolymers is the main fabrication technique for filaments, films, rods, and tubing or pipe, and involves the same concerns for thermal degradation, streamlined flow, and noncatalytic materials of construction as described for injection-molding resins. A significant application for vinylidene chloride copolymer resins is in the... 

The pastes used are plastisols—finely divided polymer dispersed in plasticizer. They are mobile mixtures which may range in viscosity from liquids that can be poured readily to thick pastes—the viscosity depending essentially on the type of resin and the amount and type of plasticizer involved. Such mixtures can be applied to substrates by coating or by techniques akin to printing after application they are converted into homogeneous flexible vinyls by heating to temperatures in the range 175 to 200 °C, when the dispersed particles of resin dissolve in the plasticizer and are fused into a continuous structure.1... 

This paper outlines procedures used in the identification of typical PVC formulations, starting with the resin and proceeding to impact modifier, process aids, lubricants, stabiliser system and fillers. The emphasis is on FTIR microscopy as the most versatile approach requiring small samples and minimal to no sample preparation. Other commonly used FTIR techniques are also outlined. Wet separation protocols, applicability and limitations as related to FTIR analysis are discussed. Typical examples include vinyl siding, packaging and bottle formulations as well as contaminants often encountered in these formulations and raw materials. 

Some specific recent applications of the chromatography-mass spectrometry technique to various types of polymers include the following PE [130, 131], poly(l-octene), poly(l-decene), poly(l-dodecene) and 1-octene-l-decene-l-dodecene terpolymer [132], chlorinated polyethylene [133], polyolefins [134,135], acrylic acid, methacrylic acid copolymers [136, 137], polyacrylate [138], styrene-butadiene and other rubbers [139-141], nitrile rubber [142], natural rubbers [143,144], chlorinated natural rubber [145,146], polychloroprene [147], PVC [148-150], silicones [151,152], polycarbonates (PC) [153], styrene-isoprene copolymers [154], substituted PS [155], polypropylene carbonate [156], ethylene-vinyl acetate copolymer [157], Nylon 6,6 [158], polyisopropenyl cyclohexane-a-methylstyrene copolymers [195], cresol-novolac epoxy resins [160], polymeric flame retardants [161], poly(4-N-alkylstyrenes) [162], pol)winyl pyrrolidone [31,163], vinyl pyrrolidone-methacryloxysilicone copolymers [164], polybutylcyanoacrylate [165], polysulfide copolymers [1669], poly(diethyl-2-methacryloxy) ethyl phosphate [167, 168], ethane-carbon monoxide copolymers [169], polyetherimide [170], and bisphenol-A [171]. 

In earlier times physical prototypes may have been hand carved out of wood or molded from clay. In modern times, polymers are the materials used most widely in RP applications. These materials include ABS, nylon, and UV-curable photopolymer resins such as epoxy, acrylates, and vinyl-ethers. This chapter describes the various techniques and devices nsed to produce RP parts and details of the polymer materials that are used. Advantages and disadvantages of different techniques such as accuracy and strength of the product are considered. 

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