Radomes Look to Ceramics
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CHLOROMETHANE from Wichita, Kansas ... • METHYLENE CHLORIDE • CARBON TETRACHLORIDE • CHLOROFORM USP A N D TECHNICAL Ο GRAIN FUMIGANT5 in carload, truck- load and drum lott Frontier offers you swift shipments from > heart of Mid-America . . . high quality from a now plant with advanced processing and control equipment. Friendly, personal service, from a firm big enough to deliver the best — and young enough to appreciate your ^business. Plant sites available next door f 'for over- the-fence" deliveries. We shall welcome your inquiry. Basic producers of Chloromethanes, BHC (14 and 30 gamma). Chlorine, Caustic Soda, Muriatic Acid, Fine Grain Salt Executive Officer Wichita, Kama» Plants: Wichita, Kansas Denver City, Texas A DIVISION OF UNION CHEMICAL & MATERIALS CORP. ADSORBENTS DILUENTS Floridin natural-mineral ad- sorbents are successfully being used for applications in ad- sorptive refining, filtration, neutralization, decolorization, dehydration, polymerization, catalysis, diluents, insecticide carriers, filters, binders, clean- ers, and many others. If your laboratory or pro- duction processes can use an economical, efficient, natural material for these or similar uses* it will pay to investigate. Write today. FÉAJHPÎN COMPANY/® ADSORBENTS Dept. B, P.O. Box 9 8 9 Tallahassee, Florida PRODUCTION Radomes Look to Ceramics Air Force tries a ceramic material—alumina—to over- come guided missile temper- ature troubles Ceramic radomes are now leading the assault on a major guided missile prob- lem. The problem: High tempera- tures (far above the range of presently used reinforced plastic) are generated when guided missiles re-enter the atmosphere. Under an Air Force development contract, Gladding, McBean & Co., a West Coast ceramics manufacturer, came up with a solution, has just com- pleted the first 10 prototype ceramic radomes. But the going wasn't easy. The big problem is that a radome must be as transparent as possible to radar waves. This means that a mate- rial with the required temperature re- sistance and strength has to have the right electrical properties too. The alumina ceramic was chosen. But manufacturing was a difficult trick since a method had to be devised which could hold the wall thickness to a tolerance of ±0.001 inch. Gladding, McBean finally worked out a technique to do this. High purity alumina (97% A1 2 0 3 ) is mixed with a small amount of organic binder to give it some strength before firing. This slurry is sprayed on a chrome-plated steel mandrel with a spray gun and the radome is then oven dried while in place on the mandrel. A neoprene bag is used to cover the whole assembly which is placed in a specially designed pressure vessel. Glycerol is fed to the vessel with a high pressure hydraulic pump which raises the pressure to about 30,000 p.s.i. Thus compacted, the radome has enough strength to be stripped from the mandrel. It is given a preliminary (or bisque) firing at 2200° to 2250°F. and then machined on a lathe with a diamond tool to final wall thickness— with allowance for the small amount of shrinkage that will occur in the second firing. A regenerative type kiln is used for the final firing at a temperature above 3000 °F. The prototype radome resulting from the process is six inches in diameter and 18 inches high. It meets the electrical, thermal, and dimensional requirements of the Air Force.- To make a radome, the spray gun coats a chrome-plated steel mandrel with a slurry made up of alumina and an or- ganic binder. The radome stays on the mandrel while it is oven dried A neoprene bag covers the radome- mandrel assembly while in a pressure vessel. This step compacts the radome before the first firing in a kiln 70 C&EN OCT. 14, 1957
Transcript of Radomes Look to Ceramics
CHLOROMETHANE from Wichita,
Kansas . . . • METHYLENE CHLORIDE
• C A R B O N TETRACHLORIDE • C H L O R O F O R M
USP A N D TECHNICAL Ο G R A I N FUMIGANT5
in car load, truck-load and drum lott
Frontier offers you swift shipments from
> heart of Mid-America . . . high quality from a now
plant with advanced processing and control equipment. Friendly, personal service, from a firm big
enough to deliver the best — and young enough to appreciate your ^business.
P l a n t sites available next doorf'for over-the-fence" deliveries. W e shall welcome
your inquiry. Basic producers of Chloromethanes, BHC (14 and 3 0 g a m m a ) . Chlor ine , Caustic S o d a , Mur ia t ic Acid,
Fine G r a i n Sal t
Executive Officer Wich i ta , Kama»
Plants: W i c h i t a , Kansas Denver Ci ty , Texas
A DIVISION OF UNION CHEMICAL & MATERIALS C O R P .
ADSORBENTS
DILUENTS Floridin natural-mineral ad
sorbents are successfully being used for applications in ad-s o r p t i v e refining, f i l t rat ion, neutralization, decolorization, dehydration, polymerization, catalysis, diluents, insecticide carriers, filters, binders, cleaners, and many others.
If your laboratory or production processes can use an economical, efficient, natural material for these or similar uses* it will pay to investigate. Wri te today.
FÉAJHPÎN COMPANY/® A D S O R B E N T S
Dept . B, P.O. Box 9 8 9 Tal lahassee, Florida
PRODUCTION
Radomes Look to Ceramics
Air Force tries a ceramic mater ia l—alumina—to overcome guided missile temperature troubles
Ceramic radomes are now leading the assault on a major guided missile problem. The problem: High temperatures (far above the range of presently used reinforced plastic) are generated when guided missiles re-enter the atmosphere.
Under an Air Force development contract, Gladding, McBean & Co., a West Coast ceramics manufacturer, came up with a solution, has just completed the first 10 prototype ceramic radomes. But the going wasn't easy.
The b ig problem is that a radome must be as transparent as possible to radar waves. This means that a material with the required temperature resistance and strength has to have the right electrical properties too. The alumina ceramic was chosen. But manufacturing was a difficult trick since a method had to be devised which could hold the wall thickness to a tolerance of ±0 .0 0 1 inch.
Gladding, McBean finally worked out a technique to do this. High purity alumina ( 9 7 % A1203) is mixed with a small amount of organic binder to give it some strength before firing. This slurry is sprayed on a chrome-plated steel mandrel with a spray gun and the radome is then oven dried while in place on the mandrel.
A neoprene bag is used to cover the whole assembly which is placed in a specially designed pressure vessel. Glycerol is fed to the vessel with a high pressure hydraulic pump which raises t h e pressure to about 30,000 p.s.i. Thus compacted, t he radome has enough strength to b e stripped from t h e mandrel. It is given a preliminary ( o r bisque) firing at 2200° to 2250°F. a n d then machined on a lathe with a diamond tool to final wall thickness— with allowance for the small amount of shrinkage that will occur in the second firing. A regenerative type kiln is used for the final firing at a temperature above 3000 °F.
The prototype radome resulting from t h e process is six inches in diameter and 1 8 inches high. It meets t he electrical, thermal, and dimensional requirements of the Air Force.-
To make a radome, the spray gun coats a chrome-plated steel mandrel with a slurry made u p of alumina and an organic binder. The radome stays on the mandrel while it is oven dried
A neoprene bag covers the radome-mandrel assembly while in a pressure vessel. This step compacts the radome before the first firing in a kiln
7 0 C & E N OCT. 14, 1957
PRODUCTION
Drying Gelatine Purity demands for gelatine are most
severe in the photographic field, although pharmaceutical and food industry needs also call for a high-quality product. American Agricultural Chemical says it uses a Rodney Hunt evaporator to get the necessary purity. The evaporator removes moisture from raw gelatine solution at a practical s p e e d -without degrading the heat-sensitive protein product, the company says.
Basic commercial processes start with pig skins or clean animal bones. Leaching in aqueous acid releases gelatine. The filtered, lime-neutralized solution is then evaporated to dryness.
AAC's new method for reducing the product to a dry powder a t its Detroit plant involves a three-step process. The critical step is the first: Dilute gelatine solution is continuously concentrated by the turbo-film processor at a rate of 2500 pounds (roughly 300 gallons) per hour. The unit removes some 1600 pounds of water in that time, increasing gelatine content from about 20 to 60%.
Rotor blades inside the processor disperse the solution into small droplets which impinge against the heated walls. The fluid immediately spirals downward in a thin film. With the liquid in constant motion, any one particle is exposed to heat only briefly. "Burn-on" and degradation are thus avoided.
Next, the hot concentrated solution is chilled quickly in a Votator. The highly thickened gelatine paste is then extruded as long "noodles" onto a conveyor belt leading into a surface-combustion dryer. This third step—the final drying—reduces moisture content down to 6 to 10%. Finally, the finished product is ground, screened, and packed by conventional means.
New Color Scale A new color scale for grading petro
leum products has been devised by National Bureau of Standards and American Society for Testing Materials. Glass standards matching the new scale are now in production.
The new scale has 16 uniform stages and covers the range from the black of crude oil through dark red, orange, lemon yellow, and pale yellow to crystal clear.
ASTM committee on petroleum products has approved the test method.
Resolves and Quantitatively Measures Approximately 9 8 % of the Ρrotein .Content, o f : S a m p i ^
SCHLIEREN
INTERFERENCE
(Analytical Model)
This instrument renders,planimetry unnecessary since it indicates on its screen a quantitative analysis of the various proteins contained within the sample tested. The machine employs the Rayleigh system which permits usé of extremely dilute solutions (only j/2 ml. of undiluted serum is needed for an analysis). Aminco's Electrophoresis includes a built-in refrigeration unit.
5-8510 Clinical Electrophoresis, complete with electrolytic compensator, 'dialysis unit, eyepiece viewer for observing interference patterns, two'film holders for 3!/4 χ Ψ/4 in. cut film; package'of'Eastman Kodak contrast panchromatic film, (24 sheets),, interference filter (546 millimicrons),'
; elapsed-time meter, mercury vapor and incandescent light sources :...........;.. $2754
Send for BuIleHn 2287-C~2
AMERICAN If^TRUMll^^OMHC
O C T . 14, 1957 C & E N 7 1
