New Flame-Resistant Plastic Announced By General Electric HE development for the Navy of a plastic, combining the qualities of fire- plus shock-resistance and easy molding properties is announced by General Electric. Intensive research begun in the company's plastic laboratory a t the request of the Navy Department, which organized an industry committee t o study the problem of developing such a plastic material, has produced a product that can withstand fire and its resultant toxic effects during battle action, as well as the concussions and vibrations of battlewagon broadsides. Modern war, fought st great distances from supply ports and with widespread use of new, powerful, and incendiary explosives. revealed the need for changes in ship design. The stresses and strains of battle action set the standard for the Kavy specifications of the material which G-E engineers and chemists sought. The specifications called for a plastic that was relatively fireresistant and nontoxic, and had good electrical properties, high impact strength, and easy moldability. The laboratov men, working with Dr. Howard W. Haggard of Yale University, learned that it was impossible t o use any appreciable amount of organic filler in a Laminated plastic or molding compound t o fit these specifications, regardless of what kind of resins were used, without obtaining a material that gave off tmic gases fats1 t o human beings, depending on several factors including the size of the room and length of burning. The chemists then turned t o the use of inorganic filler-type of materials. such as asbestos and dass. At the end of the long research ;ad they s4ertr.d abbes& as the typc of inoraanic filler they wmled b w a u r ~i~ embodied all of the $pecificatiot~r relarive h i ~ hflame-reAance, low toxicity, pa-y mnldnbility, and shock resistance. The researchers then bound the asbestos fibers together with certain phenolic resins t o make a series of plastics with various shock r&istances. G h ,the other inorganic material, is used in another plastic development far the Navy: This type of plastic is used as panel board on ships. It is made by bonding layers of glass cloth together with melamine resin in high-pressure presses. ~~~~~~~
Glass Tanks HORTLY after the stunning news of Pearl Harbor, a large
S Eastern concern, unable t o get replacements for a battery of
tanks which had been corroded by acids, asked Pittsburgh Plate
Glass CompaAy if g l a s replacements could be furnished for the emergency. Because of its brittleness glass in tanks had never been used extensively for industrial applications. With the perfection of the Herculite process by Pittsburgh, strength against breakage was boosted by four or five times. Hence, with the manufacture of the first all-glass tank by the new heat treating process about 18 months ago, the answer was found t o the need for industrial tanks where corrosive solutions posed a maintenance problem. With the exception of hydrofluoric acid and hot caustic, glass is impervious t o acids which destroy every other type of material used in tanks. The eventual breakdown of tanks of other materials has been accepted a4 an inevitable plant problem. This difficulty is entirely overcome by the use of tanks made of glass. Glass tanks have now been installed in several hundred plants and pharmaceutical houses and in steel mills. These tanks stand an instantaneous temperature shock of 400 degrees Fahren.heit and continuous working temperatures of from 500 t o 600 degrees. Pickling and plating solutions rarely are over 250 degrees. The Herculite glass shows great resistance t o impact. A piece 12 inches square and three-quarters of an inch thick, supported only a t the edges, will withstand, without cracking, the shock of having a 5-inch duck-pin ball dropped on it from a height of 26 feet. Two types of glass tanks are being produced by Pittsburgh Plate. One is made entirely qf either opaque or transparent glass five-eighths t o one and one-fourth inches thick depending on service requirements. The side walls are grooved t o take gaskets of impregnated glass cloth a t the joints and the tanks are held together by noncorrosive metal tie rods. The bottom has an inner or secondary lining of Herculite. The maximum inside size of such tanks is eight feet long by five feet ten inches wide and five feet deep. The other type has a one-half inch glass lining inside a steel shell and is used where larger tanks are required. The glass is held away from the outer shell by spacers which are designed t o put p r w u r e on the joints. The space between the glass and the outer shell contains a continuous acid-resistant membrane applied by a special process. The theoretical maximum size of glass tanks of this type is limited by the size in which the glass plates can he made. This is usually nine feet by six feet by five feet. Pyrex drains are provided for severe corrosive conditions. Tanks also have heen installed with glass hoods for removing fumes and with heating units known as candle heaters. All the metal parts of these heating units are i~$osed in glass.
SUMMER COURSES AT THE UNIV~RSITYOF PIT~SBURGH The customary eight-week summer session in the University of Pittsburgh hos been replnced by a twelve-week summer session beginning June 25. Full-year courses will again be offered. During thefirst sir weeks,first- and second-semester Inorganic Chemistry, first- and second-semester Organic Chemistry, first-semester Analytical Chemistry, and first-semester Physical Chemistry will be given. During the second siz weeks beginning August 6, second-semester Inorganic Chemistry,first- and secondsemester Organic Chemistry, second-semester Analytical Chemistry, and secondsemester Physical Chemistry will be offered. Each siz-week course carriesfour credits, ercept Physical Chemistry which is a three-credit course. In addition to these basic courses, "Fundamentala of Nutrition," a two-credit undergraduate lecture course, will be offered during thefirst s k weeks. Gmduate courses listed include Advanced Organic Chemistry, Organic Prepamtiom, Advanced Physical Chemistry, and Annlytical Instrumentation. These courses cover a semester's work in twelve weeks.
210
