July, ws.1
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shaw, Ltd., states the new mill will grind and disperse materials in onetenth of the time normally taken by the orthodox ball or pebble mill. It will also mill to semi-paste consistency, grind materials wet or dry, and can, if necessary, process four different substances simultaneously. Formulations processed in this new mill can be reproduced in bulk production with identical characteristics ; the only variable is the time factor. Applied to the paint industry, it will, for example, grind and clisperse a concentrated charge of color pigment and medium in approximately four hours, a process which normally takes at least 40 hours in an orthodox ball or pebble mill. In five, six or seven hours’ milling time, it will produce a much superior dispersion. Butyro Refractometer.-A new Butyro Refractometer designed to increase the speed and accuracy of purity tests made on edible oils has been introduced by the Bausch & Lomb Optical Co., Rochester, N. Y. The instrument will find many applications in plants processing edible oils, such as cooking oils, soybean oils, vegetable oils, shortenings, butter, and oleo, the manufacturer said. To determine butyrol number, oil samples are placed between two prisms mounted in a fixed horizontal position and light is refracted through the liquid oil. Direct readings of the refraction are made through the micrometerequipped eyepiece in butyrol number accurate to 0.1 per cent. The horizontal sample mounting position permits an unobstructed view of the oil sample and allows easy loading and cleaning of the instrument. The new B&L Butyro Refractometer has many features not available with previous instruments. Temperatures are kept constant for accurate readings with spiral flow copper heat exchang-
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ers around the prism boxes. Possibility of contaminating samples is very remote because the instrument’s clean design eliminates slits, corners or holes. The prisms of the new refractometer are mounted with special cement in corrosion-proof housings for long life. Spare prisms are also available. Technicians using the new instrument will be able to make many more butyrol cleterminations because both line and fixed scale are visible simultaneously in the eyepiece and samples are quickly changed. The built-on light source also assures simplicity of operation. Samples can be read by either transmitted or reflected light. Lifesaving Fuel Tank.-Rubberized nylon has been made into an airplane fuel tank designed to resist rupture at high crash speeds. The tank successfully passed a recent test during which it was filled with water, encased in an airplane wing, and catapulted 300 feet into a steel-backed sandbag barrier. Since many crash victims survive the impact only to die in flames when fuel tanks explode, the new ruptureresistant tank is expected to save many lives. Oil products provide safety engineers with many of their most useful materials. New Role for “Dacron.“-“Dacron” polyester fiber is being woven into a heavy-duty jacket for a fire hose developed especially for the oil and chemical industries. The natural fibers formerly used were no match for the oils, acids, and extreme temperatures found around oil and chemical plants; hose deteriorated quickly. “Dacron” shows excellent resistance under these conditions and also resists mildew from dampness. The “Dacron” jacket, impregnated with neoprene cement, covers a neoprene tube. The combination of these two oil products results in a
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hose of little more than half the weight of the conventional type, yet it withstands more pressure and higher temperatures. Its lightness and flexibility speed fire-fighting, making possible untold savings of property, and sometimes of lives. Scissors-Type Rafter Design.-A new scissors-type Teco trussed rafter design, having a lower roof slope of S-in-K?, instead of the 12-in-12 slope in previous designs, has been developed. for architects and other designers by Timber Engineering Company, research affiliate of the National Lumber Manufacturers Association, and longtime authorities on the use of engineered timber in light and heavy construction. The new typical design is particularly adaptable to small churches, chapels, and similar buildings of contemporary design. It enables the structures to retain their more or less traditional high roof pitch and steep ceiling slope, yet enables both to be lowered for more conformance with the current trend toward lower roofs. Architects will find the new design equally adaptable to commercial and industrial buildings requiring clear span construction, a pitched roof, and greater floor-to-ceiling clearance. It can also provide sloped ceilings required by architectural interior styling of some present-day dwellings. The new typical design provides data for spans from 20 feet through 36 feet, and spacings of two feet on All data are based on the use center. of Teco wedge-fit timber connectors in In addition to conforming grooves. specifications and a list of required materials for the scissors trussed rafter,
TOPICS the design includes anchorage showing how to tie the roof more securely with Trip-L-Grip ing anchors.
[J. F. I. detail down fram-
Earmuffs to Protect Hearing.-A revolutionary type of earmuff that makes men look like something from a dream of outerspace has been develThe device fits oped in Worcester. over the head like a phone set and covers each ear to muffle sound of every frequency. It was developed at Worcester Polytechnic Institute by Prof. William D. Wadsworth, several graduate students, and the David M. Clark Co. The latter financed the project which had its start two years ago. One of its proven uses is in jet engine testing where sound alone can vibrate the leather soles on a man’s shoes. Testing in a soundproof room at WPI determined that the best design was an elliptical shape for the earmuff. The outer surface is of reinforced fiber glass. A plastic foam ring seals the muff over the ear, and a plastic sponge material with a backing of chamois lines the inside. The device is more effective than earplugs, which have low acceptability among workers because of discomfort, according to Professor Wadsworth. With the new muffs, the only sound transmitted is through the bone structure of the head, Forrest R. Poole of the Clark Company says. Experiments now are underway to eliminate sound from penetrating this bone structure. It will probably be necessary to cover the entire head, Professor Wadsworth believes.