Fluorination pipe products

Pipe Products Manufactured with Fluorination Technology... 

As far as can be ascertained, no performance standards exist for this product. In the absence of such standards, the existing standards for automotive vehicles were used as guidelines. By using the most stringent standard, the SHED test, a petrol permeation rate of approximately 3.3 g/m2 for 24 h at 40°C can be estimated. With a single-fluorination treatment a pipe already exceeds this standard with a steady state permeation rate of 1.7 g/m2 per 24 h at 50°C. Since it is a known fact that permeability increases drastically with a rise in temperature, a permeability ofless than 0.17 g/m2 per 24h at 30°C is expected for a single fluorination treatment. 

Flat laminated panels are manufactured using fluorinated sheet substrates. The manufacturing of these test panels simulates the production process used to manufacture the fiberglass-reinforced pipes. The BS6464 test prescribes a minimum adhesive shear and peel strength of 7 MPa and 7 N/mm, respectively. Representative values for both tests are given in Tables 16.9 and 16.10 below. 

All TP or TS matrix property can be improved or changed to meet varying requirements by using reinforcements. Typical thermoplastics used include TP polyesters, polyethylenes (PEs), nylons (polyamides/ PAs), polycarbonates (PCs), TP polyurethanes (PURs), acrylics (PMMAs), acetals (polyoxymethylenes/POMs), polypropylenes (PPs), acrylonitrile butadienes (ABSs), and fluorinated ethylene propylenes (FEPs). The thermoset plastics include TS polyesters (unsaturated polyesters), epoxies (EPs), TS polyurethanes (PURs), diallyl phthalates (DAPs), phenolics (phenol formaldehydes/PFs), silicones (Sis), and melamine formaldehydes (MFs). RTSs predominate for the high performance applications with RTFs fabricating more products. The RTPs continue to expand in the electronic, automotive, aircraft, underground pipe, appliance, camera, and many other products. 

The fluorinated ethylene propylene (FEP) macromolecule consist mainly of a linear chain with the basic monomer unit [—(CFJ,—CF(CF3)—] .This translucent fluorocarbon is flexible and more workable than PTFE, and like PTFE it resists to all known chemicals except molten alkali metals, elemental fluorine, fluorine precursors, and concentrated perchloric acid. It withstands temperatures up to 200 C and may be sterilized by all known chemical and thermal methods. Certain carefully prepared films of FEP can be used as windows in equipment when necessary. The product has found extensive use as a pipe fitting liner as well as a liner in small vessels. 

Where unfavorable combinations of chemical, mechanical, and physical environments may preclude the use of other materials, PVF has been successfully used, as for valve and pump parts, heavy wall pipe fittings, gears, cams, bearings, coatings, and electrical insulation. Its limitations include lower service temperatures than the highly fluorinated fluoropolymers, not having antistick qualities, and the fact that it produces toxic products upon thermal decomposition. 

Polymers are familiar products in the modern world. Nylon, one of the first polymers developed, is like an artificial silk and is used in making clothing, ropes, and sails. The fluorine-containing polymer Teflon (polytetrafluoroeth-ylene) is used in nonstick frying and baking pans. Polyvinyl cWoride (PVC) is used in food wrap, hoses, pipes, and floor tile. In all, the polymer industry is huge. It has been estimated that about half of all chemists work with polymers. Of particular interest to them are the reactions that can be used to make polymers. We will briefly survey the main types of polymerization reactions. 

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