cording to Romick, but not for travel within the solar system inside this orbit. For the outer planets, trip times with present chemical propcllants would be 5 or 10 years and up. For the extreme outer planets, they would be impractical in terms of human life time. For traveling beyond the solar system velocities approaching the speed of light would be very desirable. Not that you would actually want to hit 186,000 miles per second, because then you would, the theory says, change into energy—a sensation sought by only the most jaded of thrill seekers. " I do not, today," Romick says, "have the least idea how speeds approaching the speed of light can be attained. But just as we had no idea a few years back of how to achieve the performance promised by the ion drive, so do I expect that a concept similarly advanced over the ion drive is certain to be developed during the years ahead. A.S.H.
every major chemical process plant has installed some sort of automatic weighing setup—ranging from a single scale to a complete system of a dozen or more scales. Typical applications have included automatic rejection of overweight and underweight containers, filling of cartons, blending chemicals, formulation of fertilizers, and batching of concrete and asphalt (this should get a boost in view of the recently approved Federal Highway Program).
Basically, automatic weighing systems consist of: 1. Material handli ng devices such as weigh h oppers, tanks, conveyors, or weighbridges 2. Weight or force transmitters such as mec hanical lever systems, electrical load cells, hydraulic cell!s, and pneumatic cells 3. Instrumentation such as indicators, cutoff equipment (photoelectric cell or mercury variety), recorders, dial indicators, meters, or electronic data processing machines
Pounds A-Weigh Most recent refinement in automatic weighing is a scanning device that feeds weight d a t a to a typewriter or adding machine
IXiDiNG the crest of the automation wave, automatic weighing devices have gained popularity in the chemical process industries. The big advantage : faster speed of operation— double that of manual weighing equipment. Besides, since the human element is removed, quality and quantity control is improved. And, say manufacturers of automatic weighing systems (or components), maintainence requirements are minimal. All told, the idea blends well with the completely automatic plant of the future. But, like automation itself, automatic weighing is not truly a newcomer to the chemical industry. Concepts of weighing systems got started some 30 years ago, but not until after World War II did the idea gain momentum. Now practically 16 A
In use, levers or cells are strategically placed under the weighing vessel or the vessel suspended from the weight transmitters with the aid of auxiliary equipment. Change in weight or force is converted to an electrical signal, which in turn, is transmitted to appropriate instrumentation (the latter can be placed in some remote location). Actually, automatic weighing systems are more electrical than electronic. Heart of an electrical loan cell, for example, is a strain gage. This is essentially a spring scale which is stretched or compressed in proportion to weight. This in turn produces a resistance signal which can be calibrated in pounds. The lever system, on the other hand, converts the weight into an electrical signal through a variety of means such as differential transformers or potentiometers. Levers and cells can be made to weigh anything from an ounce to a carload. Several companies specialize in automatic equipment for low weight rages. But most plant orders have been for units capable of weighings above 500 pounds. Accuracy of the devices is to the order
INDUSTRIAL A N D ENGINEERING CHEMISTRY
± 0 . 1 0 % but depends on indication and instrumentation systems. Punched card weighing is a natural corollary of automatic systems. For any batch required, an operator simply inserts a punched card in an IBM machine. This automatically activates the weighing apparatus, gates, and valves, to weigh out the desired mix. Selection can be changed instantaneously by inserting; another card. In another batching operation, a series of weigh hoppers, one for each ingredient, is placed in line to discharge onto a conveyor belt. Scales are equipped with cutoff systems. Discharge gates and feeders are interlocked through a central control panel so that each scale operates automatically in proper sequence through the entire batching cycle. The most recent development in automatic weighing is a scanning system that automatically feeds weight data into electric typewriters, adding machines, or tape punches. Scale manufacturers look for a big future here. As for the entire future of automatic weighing, despite the fact that the idea is some 30 years old, many regard it as still in its infancy. In many industries it is becoming essential to proper quality control and speed of operation. And, with the completely automatic plant on the horizon, automatic weighing should mature to manhood.
Mexican Sulfur Frasch sulfur producers south of the border are cutting into markets formerly served by domestic producers. It's the first time the U. S. sulfur industry has faced strong competition since it was born 5 3 years ago
and Mexican producers are wooing foreign consumers with lower sulfur prices. Several months ago, Frecport cut the export price $3 a ton, from $31. Price shaving started, according to trade spokes^AMERICAN
Pattern for
And this is the chronological list of some Bakélite product developments:
PROGRESS
Γ ι FT γ years ago, a man with an idea set the foundation for much of the great development in the plastics industry. Solving a tantalizing puz zle, he perfected a workable scien tific scheme. The man—Leo H. Baekeland ; the product—Bakélite phenolic resinoid. What has this to do with I&EC? O n February 8, 1909, I & EC's editors received Baekeland's original manuscript on his research work and process. T h e article was published in the March 1909 issue. The pattern begins; this was the first of many technical articles, originally appearing in l&EC's pages, which presaged the great commercial chemical developments of later years. The 1909 volume was our first—1959 will mark l&EC's golden anniversary. Each month from now until late 1958, we will show how l & E C articles published in one year set industry patterns in succeeding years. Concluding his I & E C article, Dr. Baekeland said that he wrote it to "stimulate further interest in this subject among my fellow chemists and . . . lead them to succeed in per-
fecting my methods or increase still further the number of useful applications of this interesting compound." That success beyond any of his dreams was achieved is everyday knowledge. Today, industry produces 3.5 billion pounds of plastics annually, of which 450,000,000 pounds are products related to Baekeland's original process.
1905 09 Baekeland's studies of p h e n o l a l d e h y d e reaction leads to d e v e l o p ment of Bakélite phenolic resinoid in Yonkers, Ν. Υ., laboratory (chemically — o x y b e n z y l m e t h y l e n e glycol a n h y dride). 1909 I &EC article p u b l i s h e d . 1910 Baekeland forms General Bakélite Ce. at Perth A m b o y , N. J. Aylsworth's work for Edison o n the use of phenolics for p h o n o g r a p h records leads to formation of Condensite Corp. of America. 1914 R e d m a n o l Chemical Products Co. formed to d e v e l o p phenolic materials in furniture varnishes. 1922 Consolidation of General Bakélite, Redmanol, a n d Condensite forms Bakélite Corp. 1939 Bakélite Corp. becomes a division of U n i o n Carbide a n d Carbon Corp.
1909 Ignition system distributor heads 1910 M o l d e d a n d laminated electrical parts, p h o n o g r a p h records 1911 Third rail insulator for s u b w a y a n d elevated trains 1912 Brass, furniture, a n d hardware lacquers 1913 Bakélite phenolics for packaging a n d package closures ( d e v e l o p e d in 1920 into toilet goods tube caps) 1914 Earpiece for upright t e l e p h o n e , molded instrument bases 1915 Automotive electrical system insulation 1916 H e a d p h o n e s , rheostats, c o n d e n s ers, insulating parts, knobs, a n d other radio e q u i p m e n t parts 1918 Distributors a n d molded insulation for aircraft e n g i n e s 1919 Other aviation parts, communicators, switches 1920 Airplane propellers 1921 Bakélite phenolic resins commercially supplied for such uses as b o n d i n g abrasives 1922 Phenolic resin enamels for interiors of automotive manifolds and crankcases 1923 B o n d i n g resins for b r u s h bristles a n d breaker strips for refrigerators 1924 M o l d e d into Weston voltmeter case ( b e g i n n i n g of plastic cases) 1926 Two-color contact buttons 1927 Laminated plastic ball-bearing r e tainer rings 1928 Counter plates a n d table tops, first completely oil-soluble phenolic resin for varnishes 1930 N e w thermoplastic materials— vinyl chloride acetate resin 1934 M o l d e d dentures 1937 Styrene molding plastics 1943 Commercial p o l y e t h y l e n e m a n u facture
men, when Mexican producers began selling their product below quoted prices in exchange for long term sales contracts, as a way of breaking into the market. Those in the know say these temporary price reductions are likely to stay in effect until sales are readjusted among the various producers. Other American companies have joined the price scuffle (few will admit it is a war), and this will mean lower profits for some. Seymour Schwartz, president of S. Schwartz & Associates (New York sulfur consultants), was recently quoted as saying: "Sulfur production in Mexico has been growing like a house afire, although 1954 out-
put was only 86,000 tons compared with about 6,000,000 tons in the United States." Last year Mexican production skyrocketed to 516,000 tons and is expected to reach 995,000 tons by the end of this year, he indicated. U. S. sulfur imports from Mexico in 1956 will undoubtedly show a further increase over 1955 tonnage and will represent the first sizable imports of elemental sulfur in more than 35 years, indicated the Department of Commerce in a recent report of the sulfur situation. On the subject of imports, Schwartz says: "Last year we imported about 31,000 tons, but this year we will probably reach a level of 150,000 tons. T h e
last time sulfur imports into the United States exceeded 31,000 tons was in 1906 when Herman Frasch put an end to control of the sulfur industry by Sicilian producers." Meanwhile, American exports are declining and may drop below 1,200,000 tons this year, compared with 1,600,000 in 1955 and 1,650,000 tons in 1954. At the rate which Mexican producers are boosting exports they may exceed the Americans by early 1960, although it does not seem likely that American exports will drop below a stable level of about 1,000,000 tons. New sulfur production in the United States, too, is climbing upward, which means that stockpiles will probably
l&EC's first v o l u m e contained the research report that helped the plastics industry to greatness
This is Baekeland's success:
timetable
of
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REPORTS dence of a momentary world oversupply. In the next 3 to 5 years it might well be a buyer's market, with consequent price structure adjustments and increasing stocks in the hands of producers. World-wide sulfur consumption is also increasing. Because of the guaranteed Mexican supplies, manyforeign consumers have indicated they will use greater quantities of elemental sulfur in the future instead of alternate sulfur sources such as pyrites. Since leases are costing more and plant construction is more expensive, the outlook for sulfur is "plenty of room for all" instead of "long time low prices" which might force smaller producers out of business. As one expert put it, almost everyone is welcoming the opportunity to spread purchases among more suppliers. He said: " I n the United States, you often hear subdued rejoicing; overseas they are dancing in the streets, especially in the British Commonwealth where acid producers in the past even went to gypsum as a raw material during the severe shortages of 1950-52."
Mexican Sulfur Inroads
increase above the present 3,000,000ton level. At the same time, however, U. S. sulfur consumption is steadily increasing. Texas Gulf has been working on its Fannett dome in Texas; one trade informant indicated it might be producing by 1957. He says Freeport's Lake Pelto deposit (under 6 feet of water in Louisiana) could come on stream in 1958; Texas Gulf might push its Bully Camp operation (in Texas) into production the same year. Fannett and Bully Camp are minor deposits, he said, which may be expected to produce about 150,000 to 200,000 tons annually. Lake Pelto is probably somewhat larger and might hit 500,000 tons per year. Mining offshore in Gulf waters may be 5 years away, and sizable imports from Mexico will undoubtedly slow down efforts in this direction. There are no other domes of any consequence likely to commence production along the coasts of Texas and Louisiana during this period. Those minor deposits that might come in would have little impact on the total picture. Inventories are rising in Mexico,
where Mexican Gulf, Pan American, and Gulf Sulphur are in operation on the Isthmus of Tehuantepec. Pan American's stocks are now in excess of 300,000 tons and the company plans to boost annual output above 1,000,000 tons when its boiler capacity is raised to more than 5,000,000 gallons per day late this year. Trade reports have indicated that Gulf Sulphur might have a stockpile of 150,000 to 200,000 tons by the end of the year. Texas Gulf floated its power plant to Mexico on barges in June and will soon be in production. Three companies which have been prospecting in Mexico (Isthmus, Texas International, and Texas Gulf Sulphur) are known to have probable additional deposits. Pan American also has an additional holding. Considering the slow rate at which things have moved in Mexico, it is doubtful that any of these will add sufficient production during the next 3 years to have any material effect on the over-all picture. Added production from Mexico will in the long run have little total effect on prices, some say. However, the recent price scuffle is some evi-
Corny Chemistry Have some low cost molding plastic. It's made from waste materials, and if you're willing to pay 6 cents per pound, talk to lowa State College's Lionel K. A r n o l d . He makes it from corncobs I ^lo ORGANIC chemist ever forgets the nongraphic equation: corncobs • furfural Iowans thought they might have to learn a second step for reacting the furfural with a phenol to produce a plastic, assuming that the plasticlike lignin would act as extender and the cellulose would be a filler. But it wasn't so simple. Workers soon found that the lignin reacts with both the phenol and furfural. In addition, phenol and sulfuric acid each reacts with the cellulose. Early work showed that production of a good plastic resin was a V O L 48, NO. 8
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