Fuel tanks, automotive polymers

Fluorination of polyethylene surfaces leads to an increase in the surface energy, some degree of cross-linking and a reduction of the free volume of the polymer. All of these effects impart on the surface of the polymer a barrier that is very impermeable to hydrocarbon solvents. A blow-moulding process, in which a low concentration of fluorine in nitrogen is used as the blow-moulding gas, is used for the production of plastic fuel tanks for the automotive industry (Airopak , Air Products) [51]. Post-treatment of hydrocarbon surfaces with fluorine is an alternative technology and techniques for the surface fluorination of natural and synthetic rubber have been described [52]. 

High density polyethylene (HDPE) is used to make automotive fuel tanks as is an alternative material to steel. HDPE has many advantages over steel, especially the design freedom to utilise unused space and low weight. However, the shortcoming of HDPE is its permeability to gasoline and methanol so, therefore, it cannot maintain the right emission standards. Since the permeability of the liquid in the polymer depends both on the nature of the bulk as well as the surface of the polymer, the surface modification of this... 

Major polymer applications automotive (fuel lines and connectors, fuel pump components, fuel tanks, filters, injection rails, air inlet, manifolds, gears, wheel covers), gears for business machines, liners for flexible fuel hoses, automotive fuel system components, industrial molded parts, film fibers... 

An alternative approach to the recovery of automotive plastics is therefore to use them as large, easily removable components that offer potential for reclamation as well-characterized individual polymers. Some particularly complex components such as vehicle front- and rear-end systems, exhibit special suitability for manufacture in plastics instead of metals because of their ease of production and assembly. It is generally recognized that improvements in automotive scrapyard economics may be best achieved by the prior removal from vehicles of such large polymeric components and their recycling as well-characterized plastic fractions. For example, plastic fuel tanks of HOPE are now in common use and represent the most common recyclable plastic component. Trials with material recovered from used plastic fuel tanks have shown promising results for the manufacture of new tanks [6]. 

Basell (USA) [6] have reported on the development of a family of high-density polyethylene (HOPE) resins which have a high resistance to bio-diesel fnels and it is currently being developed for use in automotive fuel tanks. Exposure of fuel tanks to biofuel for 11 years at 40 °C has, to date, produced no significant deterioration of the polymer properties and it is significantly better than the deterioration that occurs with current low-density polyethylene (LDPE) grades nsed in fuel tanks. 

Thin-film capacitors for computer chips Solid polymer electrolytes for batteries Automotive engine parts and fuel tanks Impellers and blades Oxygen and gas barriers Food packaging... 

Major polymer applications appliances, automotive (doorhandles, window winders, tank filler necks and caps, carburetor, screw caps for cooling system expansion tanks, fuel piunps) phones (diahng units and slider guideways), pneumatic components, parts of textile machines, shower parts, home electronics and hardware, bearings, cams, containers, pump impellers, rollers, springs, clips, and many other applications... 

The most common application of vegetable oil-modified polyamides is in the surface coatings and paints industry. The dimer acids of tall and soybean oils and amines are used to modify the flow behaviour of paints. This thixotropic flow prevents setting and sagging, enables easy application and improves surface appearance. Vegetable oil-based nylons are used as engineering polymers in the automotive and transport industry for fuel lines. Products are also used for the extruded and moulded components of fuel systems such as filler necks, gas tanks, reservoir modules, filters, fuel rails and vapour recovery systems. Nylon 11 is also used in power coatings to coat metals that must withstand abrasion, impact and corrosion. 

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