Fluoropolymers fabrication

Randa, S. K., Extrusion Foaming of Coaxial Cables of Melt-fabricable Fluoropolymer Resins, presented at the 30 International Wire and Cable Symp., Cherry Hill, NJ, Nov. 18, 1981 also DuPont Publication No. E-90839-1, Jun. 1999. 

The PVC formulations shown in Table 2 represent typical compounds used by the wine and cable industry. PVC compounders have developed new PVC-based formulations with very good fire and smoke properties (can pass the UL 910 Steiner Tunnel test) that compete with the more expensive fluoropolymers. These can be used in fabricating telecommunication cables usable for plenum area appHcations. 

Packing of York-Fiberbed high efficiency mist eliminators consists of ceramic, glass, polypropylene, fluoropolymer fibers. Cages and frames are fabricated from all stainless steels and other weldable alloys as well as FRP. 

Modem membranes usually consist of at least two layers one from sulfonic type copolymer and another from carboxylic type copolymer. The membranes are usually reinforced by fluoropolymer fabric to provide better mechanical properties and long lifetimes. The most important properties are considered in detail in the reviews mentioned above10,11 and in a basic text by Seko et al.6... 

Uses Organic synthesis vapor degreasing and cold cleaning solvent for fabricated metal parts textile processing aerosol propellants synthesis of fluoropolymers production of various coatings and inks may be ingredient in adhesives, cutting oils, and aerosol formulations pesticide. 

Fluoropolymers (PTFE, FEP) were used to fabricate microstructures, which were etched by Ar ion beam etching (IBE) [225],... 

The driving force for the development of THV Fluoroplastic was the requirement for a fluoropolymer that could be used as a coating for polyester fabrics and provide... 

The use of polymers with a low relative permittivity, see Section 2.7, as the FET gate insulator has been found to result in higher carrier mobility and improved device performance (Veres et al., 2003). The authors developed stable semiconductive polymers, poly(triarylamines), and used them to fabricate FETs with silicon dioxide and poly(methylmethacrylate) gate insulators. Values of the carrier mobilities measured in the FETs were about 10 times smaller than those determined by TOF experiments. A dramatic increase in FET mobility was observed when a low permittivity fluoropolymer (e = 2.1) was employed as gate insulator. The FET mobilities for devices with gate insulators with relative permittivities in the range 2-18 are shown in Fig. 10.12(a). The devices were made with two different poly(triarylamines)... 

Certain substrates (woven and nonwoven fabrics, foils, and films) are coated by dipping, spreading, or spraying with fluoroelastomers in liquid form. The older method using a solution of fluoroelastomers in volatile solvents (e.g., methyl ethyl ketone, toluene) is gradually being replaced by the use of water-based latexes. Fluoroelastomer latexes can also be used for chemically resistant and heat-resistant coatings. Some fluoropolymer producers offer latex in limited quantities to processors skilled... 

In this entry, the classification, preparation, properties, fabrication, safety considerations, and economics of fluoropolymers are discussed. Monomer synthesis and properties have also been discussed. Increasing the fluorine content of a polymer increases chemical and solvent resistance, flame resistance, and photostability, improves electrical properties, such as dielectric constant, lowers coefficient of friction, raises melting point, increases thermal stability, and weakens mechanical properties. 

Because of its high viscosity (10 °-10 poise at 380°C), PTFE cannot be fabricated by melt-processing techniques. Melt-processible fluoropolymers have been developed by copolymerization of TFE, and FEP, a copolymer of TFE and HFP, has a lower maximum continuous use temperature than PTFE (200° C vs. 260° C) because of the deterioration of mechanical properties. Whereas, PFA, a copolymer of TFE with PPVE or PEVE, offers thermal stability, melt-processibility, and a maximum continuous use temperature of 260°C. Both FEP and PFA are considered perfluoropolymers. 

Fluoropolymers are chemically stable and inert or relatively unreactive. Reactivity, generally, decreases as fluorine content of the polymer increases. Fluorine induces more stability than chlorine. Fluoropolymers can produce toxic products if overheated. Precautions should be taken to exhaust any degradation fragments produced during the processing and fabrication of parts from fluoropolymers. 

OD applications are those fabricated from nonpolar polymers with low surface free energies. The most commonly used OD membrane materials are polyolefins, such as polyethylene and polypropylene, and fluoropolymers, such as polytetrafiuoroethylene (PTFE) and polyvinylidine difiuoride (PVDF). ... 

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