CHEMICAL & ENGINEERING
NEWS VOLUME
39, NUMBER 4i
The Chemical World This Week
OCTOBER
9, i96i
Trend to New Materials in Autos Slows Zinc castings hit comeback trail as auto makers mull advantages of light metals, plastics Minor victories and defeats mark the picture for new materials in 1962 autos. Among metals, zinc seems to be posting the best gains with use up 15 to 20% from 1961 levels. Chrysler and American Motors have joined the parade to use galvanized steel sheet for door sills, leaving only StudebakerPackard as the holdout. Zinc die castings are making something of a comeback, displacing aluminum in the grille for the Buick Special and magnesium as an alternate material for the Dodge Lancer instrument cluster. In light metals, aluminum use will gain at Chrysler. Stepped-up production is slated for the die cast aluminum six-cylinder engine. Chrysler is also using aluminum die castings for the housings of its new starter and new manual steering gear. On some Oldsmobile models a wide side rail is made of anodized aluminum. But over-all, aluminum use in 1962 autos is up only about 7% from 1961 levels or about half the recent rate of gain. The biggest new use for magnesium is probably in a rotor and stator for Chrysler's new heater blower with a total weight of 1.9 pounds. But it begins to look as though magnesium producers won't achieve their goal of 3 pounds of magnesium per car by 1962. Plastics use is up a little, probably from 25 pounds per car in 1961 to as much as 30 pounds in 1962 models. The Buick Special is using high impact polystyrene instead of sheet metal in the heater distributor assembly and the big Buicks have switched from sheet metal to acrylonitrile-butadienestyrene plastics for the instrument panel shroud. Chrysler is using linear
NEW CHEVROLET. The 1962 Chevrolet convertible received a thorough study from this pensive onlooker. Detroit made few major materials changes in its 1962 autos. Chevrolet did not follow Ford's lead to the "lubeless" chassis
polyethylene for kick panels and is doubling use of Dow's Ethafoam polyethylene foam. American Motors is using linear polyethylene in the rear wheel panels of its station wagons. The swing to Dowgard engine coolant by American Motors and to a similar two-year coolant-antifreeze by Ford may signal an industry-wide trend. Chrysler is known to be evaluating a similar move. Apparently General Motors is in no hurry to follow. But most of the industry followed Ford's lead to the "lubeless" chassis, with chassis bearings packed
with a molybdenum disulfide-based lubricant and covered or sealed against dirt and water. Chevrolet is a notable exception to this trend. Up to 4 ounces of special lubricant per car are involved, a tidy new market. The dearth of innovation in materials for the 1962 models isn't really surprising. For one thing, 1962 is little more than a face-lift year with only minor changes slated in existing models. Some Chrysler-built models and the new Chevy II and the Ford Fairlane are the exceptions. The 1963 models could be a different story. OCT. 9, 1 9 6 1 C&EN
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Major changes are now slated for most 1963 models. Aluminum. The aluminum alloy engine is by far the biggest materials change to come out of Detroit in recent history. Today some 10% of autos being built in the U.S. are powered with aluminum engines. Total aluminum use by U.S. auto makers worked out to nearly 63 pounds per car in 1961 with the new aluminum engines contributing nearly 8 pounds of this average. In 1960, the average figure for all cars was about 54 pounds per car. The new compacts averaged close to 120 pounds per car for 1961. Ford has shied away from aluminum engines. Instead Ford has turned to ultramodern foundry techniques, has come up with cast iron engines which are competitive with aluminum engines in weight. New foundry core binders such as Quaker Oats' furfuryl alcohol permit closer casting control and thinner wall sections. The result is that Ford's new 221 cubic inch V-8 weighs about 450 pounds. Chrysler's 225 cubic inch aluminum six weighs 478 pounds and Buick's 198 cubic inch V-6 weighs 430 pounds. Although aluminum's onslaught on Detroit has slowed, it is far from over. Some 75% of 1962 models sport aluminum grilles compared with about 70% in 1961 and less than 60% in
1960. Then too, the rumor mill has GM readying aluminum engines for its big cars in 1963. It's said that GM is seriously considering turning to die casting. And American Motors is reported close to successful mass production of aluminum cylinder heads for its aluminum engines. Also brightening aluminum's outlook are recent price cuts (C&EN, Oct. 2, page 3 1 ) . The near term outlook for magnesium is less rosy. The 1961 models averaged about 1 pound per car. For 1962, use will be only a shade higher. On the horizon are big items such as magnesium transmission housings—Chrysler, for one, is reported working on these. Zinc Regains Favor. Last year, the new compacts averaged only about 35 pounds of zinc die castings per car. Full sized cars averaged 75 pounds. Competitors such as aluminum have been picking off vulnerable zinc markets such as grilles. But 1962 looms as a year of recovery for zinc die castings. Buick Special has shifted to a zinc grille from aluminum. This is significant because the Special is a compact. There is talk that other makes are mulling a switch to zinc. Behind this could well be the improved chrome plate now available (C&EN, July 25, 1960, page 48) and zinc's reportedly lower cost. Die cast zinc has
VALIANT. The instrument panel shroud in Chrysler's 1962 Valiant is made of Du Pont's acetal resin, Delrin. Use of plastics in the 1962 autos is up a little, probably from 25 pounds per car in 1961 to as much as 30 pounds per car. But auto makers are showing more caution in using plastics on the new models
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C&EN
OCT. 9, 1 9 6 1
also displaced magnesium in the Dodge Lancer instrument cluster, another gain in a compact. The advent of compacts and unit body construction has proved a real boon for galvanized steel sheet. Per car use of galvanized shot from 19 pounds in 1955 to more than 70 in 1961. Compacts averaged 110 pounds in 1961. Ford and GM have been the big users of galvanized. With Chrysler and American Motors in the fold for 1962 the average will be substantially higher. And if General Motors goes to unit construction in 1963, use of galvanized steel sheet could easily double. Plastics. After posting big gains in the past decade—weight per car doubled every five years—plastics are finding the going tougher. Apparently no major part is being switched to plastic for the new models. One reason is caution on the part of auto makers. Plastics have done well when invading internal decorative trim markets. But today plastics are being pushed for functional uses where performance standards are much higher. Ford, for example, has deliberately slowed its move toward plastics. Instead, emphasis is going toward developing test methods for production and quality control of plastic parts. The message has already reached plastics makers. Dow, for one, has been offering Styron 440, a high impact, high temperature resistant polystyrene, for auto use. But Styron 440 wasn't specifically designed for auto use. Cost was a bit high for performance. Dow now offers Styron 444, a similar material but designed specifically for auto use. Look for other plastics makers to follow suit. The outlook for plastics is reasonably good, especially if the downward price trend continues. Spots for immediate gain include insulation in headliners and carpet backing. Some GM models are using polyethylene-backed carpeting for 1962. Cadillac is using a cellulosic material in its headliners and a partially cured butyl in the front floor area and cowl sections. On the horizon are auto seats made entirely of urethane foam attached to light metal frames. One of the big three is hard at work on reinforced polyester radiator surge tanks. Onepiece plastic accelerator pedals are being studied by Ford. And plastics are gaining favor fast for short run dies, jigs, and other tooling.
