Battery cases

Polypropylene. Polypropylene (PP) is used ia packagiag appHcations as films and ia rigid containers. Battery cases could be considered another packagiag appHcation. Dead batteries are often collected at the poiat of sale of new batteries. In the U.S., some states have laws mandating this. Lead, acid, and plastics, particularly PP from battery casiags is recovered and recycled (3). Care must be taken to limit worker exposure to lead duting this process (44). PP is also recovered from bale wrap and other PP fabrics used for wrappiag ia the textile iadustry and from other containers (45). 

Eew of the products in which polypropylene are used can be recovered in commercial quaUties. An exception is battery casings. In 1994, U.S. capacity for recycling polypropylene from battery casings was 265 million pounds aimuaHy (45). About 75% of the recovered polypropylene is used in new battery cases which have a recycled PP content of about 50%. Total polypropylene recycling capacity was 350 million pounds aimuaHy for an operating rate estimated at 71—90% (45). 

Polypropylene is used in battery cases and in the replacement of metal parts in automobiles. It is also widely used in consumer products, eg, kitchen wares, trays, toys, and packaging materials. Its future appHcations are expected to include an increased portion of the fibers and filaments markets, especially for continued growth in carpet backing and carpet face yams. Film, both oriented and unoriented, is also expected to be a significant growth market for polypropylene. 

Until the 1960s, reclaimed mbber was an important raw material in molded and extmded mbber products, eg, tires, mbber mats, and hard mbber battery cases. With the advent of vinyl, other plastics, and less expensive oil-extended synthetic polymers, reclaimed mbber sales stabilized and decreased. In 1973, the oil embargo and rising energy costs increased costs of the energy-intensive mbber reclaiming process to the point where they matched virgin polymer costs. Increased radial tire production required crack resistance that could not be provided by reclaimed mbber compounds (46). 

Tlie piismatic sealed cells are not self-supporting and are nomiaUy used in battery operation where the battery case is used to constrain cell cases because internal cell pressures in the range of 690 kPa (100 psi) are common. 

SAN is also used for pharmaceutical and cosmetic packaging. Usage breakdown for Western Europe in the early 1990s has been estimated at 28% for household products, 21% for domestic electrical applications, 8% for battery casings, 12% for pharmaceutical/cosmetic packaging and a large figure of 31% for other applications. 

Prior to smelting, batteries are usually broken up and sorted into their constituent products. Fractions of cleaned plastic (such as polypropylene) case are recycled into battery cases or other products. The dilute sulfuric acid is either neutralized for disposal or recycled to the local acid market. One of the three main smelting processes is then used to reduce the lead fractions and produce lead bullion. 

The plates are dried and cured under controlled temperature and humidity conditions producing no wastewater or particulate emissions. Cured plates are sent to a three-process operation that involves manual separation of the plates, stacking them with non-conducting separators, and the welding on of metallic lead battery leads (pronounced leeds ) and lead terminals. The plates are then assembled Into battery cases. 

For new components, the nickel coating is usually 25-250 im thick. Normally, the deposits are not machined. Applications include pump bodies, laundry plates, heat exchanger plates, evaporator tubes, alkaline battery cases and food-handling equipment of various sorts. 

Diallyl Phthalate (DAP, DAIP) Powder Excellent humidity resistance. Withstands temperatures over 400 F. Easily processed. Dimensional stability excellent. May be compression, transfer and injection molded. Low cost. Precision potentiometers, RF connectors, waveguide auxiliaries, attenuators, heating panels, heated battery cases. 

A much more heavily crosslinked material can be obtained by increasing the amount of sulfur in the mixture, so that it represents about a third of the mass of the product. Heating such a mixture of raw mbber and sulfur at 150 °C until reaction is complete gives a hard, thermoset material that is not at all elastic. This material is called ebonite and is used to make car battery cases. 

Phenol-furfural resins find limited application in the moulding of thick parts such as television cabinets, storage battery cases, etc. 

Polypropylene (PP) is used in a variety of areas, from snack food packaging to battery cases to disposable diaper linings. It is frequently interchanged for polyethylene or polystyrene. 

Using the manufacture of PP battery cases as an example, the authors show how to produce thin-walled (2-5mm), foamed articles with good surface properties by means of low pressure injection moulding. Neopor 35 was used as the blowing agent. 5 refs. 

Total recycled thermoplastic resin production almost tripled between 1990 and 1995 and is well over 1 billion lb per year. The percentage breakdown of the amount for recycling is the following HDPE (especially bottles), 35% PET (soft drink bottles), 34% PP (auto battery cases), 14% LDPE (film), 9% PS (packaging), 3% PVC, 0.5% other, 4%. 

Injection molding (containers, lids, bottles, toys, plastic chairs, luggage, steering wheels, battery cases, fan shrouds, air cleaner ducts), 31% fibers and filament (carpet backing, indoor-outdoor carpeting, rope), 30% resellers, distributors, and compounders, 23% film and sheet, 11% blow molding, 2% miscellaneous, 3%... 

The BSWS is applicable to soils containing battery casings, casing chips, or metallic lead. Much of the lead removal is achieved by separation of the battery casings, and metallic lead from the feed soil. Typically, the heavy metals concentrate in the fines fraction of the soil (less than 150 mesh), and the BSWS separates this fraction from the more coarse soil fractions. 

At the Zabel Battery Snperfund site, an in sitn application of MAECTITE technology was nsed to treat 17,500 tons of material consisting of soil, batteries, battery casings, debris, scrap metal, railroad ties, white goods, rubble, and wood. The site covered 0.5 acres, and treatment reached a depth of 1.5 ft. The vendor states that project costs were approximately 420,000 (D15712K, pp.29-32). 

Cobalt finds applications in permanent magnet production, and in sealing glass to metal. Zinc is used in galvanized and ferrous castings, die-cast parts, brass wire, dry cell battery cases, soldering flux, CRT phosphors, and zinc ferrite inductors. 

OPEN UP BATTERY CASE CAREFULLY WITH A CAN OPENER AND CLEAN THE ZINC CASING. 

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