TECHNOLOGY
Radial-Ply Tires Blur Tire Cord Picture Heavily favored rayon may cramp new efforts by nylon to penetrate the original equipment market At a test track in Detroit last week a small American-made sedan stormed full tilt into a tight turn and accelerated smoothly into a high-speed straightaway. No slip or skid, no tire squeal—despite a deliberately water-soaked track. New "miracle" tire rubber? No. The test car was fitted with radialply tires. Such tires have cord running radially at 90 c to the direction of travel. They also have a "belt" of cord under the tread which braces the tire and tread. Conventional tires have cord crisscrossing in a herringbone pattern at about 35° to the direction of travel. Radial-ply tires are now being tested bv all U.S. auto makers. Thev
could show up on one or two 1965 models sometime next year and are a good bet on several 1966 models. Problems for Nylon. Right now rayon (one or two plies) is a runaway favorite for the cord material in the tire carcass. Less clearcut is the material situation for the belt. European radial-ply tires use either rayon (four plies) or steel wire (two plies). American radial-ply tires will use one of these two materials. Auto makers' insistence on a soft ride will probably dictate that radialply tires for new cars have all rayon cord. Tires with steel cord give a harder ride. But some radial-ply tires for the replacement market may
ROLLS EASILY. Stripped down section of Goodrich's radial passenger tire shows two layers of steel cables which permit the tire to roll easily. Cords in the new tire run perpendicular to the direction of travel. This construction gives greater resistance to punctures and damage from chuckholes, Goodrich says
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show up with steel cord in the belt. Good candidates for the future are polyester for both the carcass and belt, and glass fiber for the belt. Conspicuous by its absence is nylon. Apparently no U.S. tire maker is planning now to use nylon cord in radial-ply tires for passenger cars. The reason given is that nylon stretches too much, a property which leads to instability in a tire with radial plies. If radial-ply tires catch on in the original equipment market—and many signs point that way—tires with nylon cord may find all doors closed tight in Detroit because of nylon cord's tendency to flatspot. Rub-off from the original equipment market to the replacement market may eventually weaken nylon's stranglehold on the replacement market (nylon has some 75% of this market). This situation may account for stepped-up efforts by nylon producers to crack the original equipment tire market. Witness Allied Chemical's recent claims for a nonflatspotting nylon, Du Pont's efforts with nylon N-44, and Chemstrand's process to reduce the flatspotting problem in nylon cord tires. At stake is the 450 million lb. $325 million market for tire cord and fabric. In 1963, nylon accounted for nearly 50% of all tire cord made, with almost all going into the replacement tire market. Rayon cord production in 1963 totaled 196 million lb., down 6% from 1962 and continuing a decline of several years. About 110 million *lb. went into original equipment passenger car tires. If all-rayon cord radial-ply tires gain favor, the downtrend in rayon cord may well be reversed. Long Mileage. There is plenty of incentive for the car makers to switch to radial-ply tires. As the test tracks (and wide public use in Europe) have shown, radial-ply tires offer better cornering power and adhesion on wet pavement. Other advantages
Perfect for washing the family owl We'll send you test results, samples, suggested forGreat, too, for dogs, giraffes, swans... or any other mulations and other technical information to prove glassware. Silverware, too. The available chlorine in FMC's chlorinated cyan- our point... if you contact Dept. 1833B-2. One word of caution: real owls don't give a hoot urates (CDB®-59andCDB-60) promotes free rinsing when they're washed in CDB's. Ever. and clear drying. No water spotting. No stain residue. Safe and easy to handle, too. Because they're dry. In either powder or granular form. For both com- \tfflC\ INORGANIC CHEMICALS DIVISION mercial and home machine dishwashing compounds. I B B ® 633 THIRD AVENUE, NEW YORK, N. Y. 10017
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claimed include up-to-doubled tread life because the braced tread squirms less, and better resistance to tread bruising and punctures. Car owners can expect greater fuel economy because a radial-ply tire rolls about 25% more easily. The biggest disadvantage, especially from Detroit's point of view, is a relatively hard ride. Car makers are now working with tire makers to engineer out this ride problem. Every major domestic tire maker is hastening to market radial-ply tires in the U.S. By early 1965 a limited range of sizes should be available. Goodrich, Firestone, and General will make them in the U.S. Goodyear and U.S. Rubber will import radial-ply tires from their European subsidiaries at first, then shift to U.S. production as demand warrants.
Ultrasonic Generator Operates At 800,000 Cycles per Second A multipurpose, high-frequency sonic generator has been introduced by Macrosonics Corp. Type 250FF Multisons generator converts 115-volt a.c. electricity to a higher voltage and at a single frequency of about 800,000 cycles per second where the effects of this high energy are often different than those observed at lower frequencies. According to the Carteret, N.J., company, previously available generators were limited to about 100,000 cycles per second. This high-frequency energy is conducted through an insulated, flexible cable to a cylindrical piezoelectric transducer. The transducer transforms the high-frequency electrical oscillations into mechanical vibrations. When activated and submerged in an aqueous or nonaqueous liquid, the transducer creates a highly directional and powerful acoustic field. This field can reach a total output of up to 80 watts, the company says. Acoustic energy is carried back and forth through the molecules in the solution along the direction of propagation of the ultrasonic energy. The company says this energy is compacted into a 6° solid-cone angle from the face of the transducer. Within the cone of energy alternating adiabatic compressions and rarefactions are produced, with changes in density and temperature. The submersible transducer can also provide sonic energy radiation 50
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Digester to Have Polished Interior Surface The mirror finish on this polished stainless-clad steel plate will form the interior surface of a new digester being built for sulfite pulping at the Prince Rupert Division of Columbia Cellulose, in Vancouver, B.C. Made by Lukens Steel, the plate is part of a 72-ton order furnished by the company for construction of the digester, Columbia's third using luster-polished plate. It has proved highly effective, according to Lukens, in minimizing pitting-type corrosion. The first vessel with a polished interior surface has been in continuous operation five years. E 31
through a 0.004- to 0.008-in. Mylar membrane. In this technique, direct contact between the solution and the vibrating ceramic face of the transducer is avoided. Applications. Ultrahigh frequency sonic energy hasn't gained wide use, according to Macrosonics, because suitable commercial equipment in the high-frequency range hasn't been available. The company notes, however, that some uses of high-frequency ultrasonics have appeared in the technical literature. Examples of possible reactions which can take place under this type of energy include the formation of fluorescent materials by the action of ultrasonic waves on cytosine, and the oxidation of phenol in an ultrasonic field. The use of ultrasonics on emulsions has also been reported. In addition, the effects of ultrasonics on the genesis and properties of heterogeneous catalysts have been reduced to practice on a limited scale. The effectiveness of ultrasonic energy to activate catalysts and accelerate a chemical reaction has been demonstrated in West Germany on a laboratory scale using two prototypes of its generator, the company says. The firm adds that a model for large-scale processing is scheduled for delivery in 1965. E 30
Rate of Heat Transmission Measured from 25° to 1200° C. A highly accurate, wide-range thermal conductivity instrument has been developed by 3M Co., of St. Paul, Minn. It is designed to measure rate of heat transmission, operating over a range of 25° to 1200° C. Accuracy, according to 3M is ± 5 % . The new instrument can be used for various materials, including metals, ceramics, plastics, glass, resins, and other solid materials. It uses a steadystate comparative method of measuring thermal conductivity, comparing the value of an unknown material with that of a known material. An advantage of the instrument, according to 3M, is that it requires a sample only 1 in. in diameter, compared to the 9- to 12-in.-diameter samples generally required. Large samples of new materials, the company says, often aren't available. Furthermore, large samples tend to warp when heated and don't stay flat. This takes its toll in accuracy. The instrument is designed around a ceramic guard tube housed in a metal case filled with insulating material. Seven heaters are wound around the guard tube. In operation, the unknown sample is sandwiched between two identical
