Document dY1wO5mZzRybaMe3LBYg3K6JR

/ eooo case. moj tuJ' l Extract from letter received from Mr. NELSON. KOBE. 5th February, 1940, ? HOCK-WOOL, A year ago I made mention of this and in the interval a lot has been done to develop both the production and use of this substitute C material here. I enclose translation of an article on same which appeared in the "Oriental Economist" last year. This, and also the "Further Mote" appended to It, were written by the President of the largest of the two producers bringing out this new material; the prospects are accordingly expressed very optimistically - particularly with regard to the expected production of 20,000 metric tons p,a. Under separate cover I send you samples of this material; Grade "A" is sold at about 15,13,-. {#62.45), and "B" at about 14.11.5.(^57,67} per 2000 lbs, I have also sent you a sample of "Millboard" made from same. An experiment has also been made to manufacture a mixture of "Rock Wool" and Cement into a Corrugated Tile, but the sample is not worth your attention, and you will doubtless agree that this material will not lend Itself to act as a substitute for asbestos in either wet \? or dry mixture with cement. Together with Spun Glass it will, however, find some, market here, ____ !> 1 E un0G0 case nan ROCK WOOL AND GLASS FIBRE. - ` by Sampel Katukura, ,, (Ur.Kutakura le president of the Nltto (Spinning Co., one of the leading prod ucers of staple fibre and other synth(etio textile materials. Everywhere in voloanic Japan there is an abundance of Lava. Indeed it may not be too much to say that about 20# of the country's surface is covered by this particular type of rock. During the eruption of a volcano the form of Lava known as "Pele's hair" may be produced, and this ' i substance is Natures* rock wool, a fore runner of man-made rock wool. ; Volcanic Japan is therefore so well equipped by nature for the produe- r tion of this interesting fibre that no other country in the world is in ! a position to compete effectively in its production, . ( Fibre produced from volcanic rock has an excellent heat preserving property, and while tho technique of manufacturing it into an effect- * ive textile fibre has not yet been evolved, tho impression prevails that a practical method will be developed before very long, i ! A8 a substitute for asbestos for insulating purposes, rock wool has : already aeveloped a definite field of application and is widely Imown ; by the name of artificial asbestos. Japan is a fairly large consumer ! of natural asbestos, as is evidenced by the imports from such leading i world sources as Canada, Africa and Soviet Russia. The nations* Imports amounted to 20,000 tons in 1935; 30,000 tons in 1936 and 50,000 :j tons in 1937, and have been growing consistently. Japan*s resources , of natural asbestos are ruther limited and offer comparatively little j prospect of being developed Industrially under the prevailing clrcums- ' j tances. This lack, however, la more than offset by the rock wool re-' ; ; sources referred to above, which are extensive und ready for immediate ' j ,, tapping, *s* I .* Rock wool is not at all fragile as is slag wool; it fulfills every requirement demanded of'natural asbestos, and its future is one of un qualified optimism. Manufacturing facilities sufficient to turn f out 100 metrlo tons of tho material aro scheduled to be completed L by end of thio year, and when thoy are in full operation Japan* s asb estos needs will be supplied on a basis very near to self-sufficiency. Rock wool has various other valuable properties beside that of pre serving heat. It is sound arresting, heat resistant and is useful for filtering, machine packing jind. slato making purpooes. In view of present day air defence needs, rock wool manufactures should be able to create a broad market for national defence and general structural purposes, while tho noiso Insulating quality of the product may.be ex * ploitod in both surface und underground transportation systoms and other sound proofing uses in cities und towns. | i In' tho field of glass fibre production Japan has made good progress and is now producing a thread that consists of several hundreds of filaments. The finest textile fibre thus far made is staple fibre of 1.5 | \ 2- deniers, whereas the filament in the Japanese glass fibre yarn is so fine that it measures only about 5 microns in diameter or one fifteenth to ono twentieth as much us a singio staple fibre filament. Tape made of this glass fibre yarn, has good strength and durability, and the day may not be far distant when pieuo-gooda for wearing apparel ure success fully produced from this material. For the time being, howevor, the most extensive use for the product is believed to be as electric motor Insulation. The insulating mater ials now generally employed ure organic substances, but as their resist ance to heat is very low, the motor has to be operated at a low temper ature and consequently only a small amount of electric current can be , used. At the sumo time, in order to insure safety the electric motor ^ must huve a bullc altogether out of production to the capacity. The use of an Insulating material with a much higher degree of heat resist ance and which would last much longer in service, would revolutionize motor design. . . ^ ' Glass fibre is un ideal material for thl3 purpose. It has u high degree of heat insulating property und a strong resistance to heat, und would permit a motor to uccommodato a greater volume of electric current. It is thought that by using this insulating material It will be possible to Increase the pov/or output of motors to three times the present quan~ tity. Moreover, in contrast to the present practice of operating motors at temperatures as low as SO to 60 degrees Celsius, the same motors if insulated vdth glass fibre may be operated with perfect safety at temp* erature of 200 to 300 degrees Celsius or even higher. ' A smaller motor means a saving in the materials of v/hlch it is manufactured such as iron and steel, oopper wire, etc. Another advantage would be found, for example in the design of the tram car, the body of which must be set fairly high above the wheols, with the result that rocking and swaying are accentuated. Owing to its small size, a glass yarn Insulated motor will enablo the floor to be placed considerably lower, which would reduce this undesirable effect. 1 . . I : ' . ^ The use of the new insulating material should virtually eliminate th* danger of fire from short circuiting, because, unlike the insulating materials now used, it does not deteriorate with age. . ; c - The Oriental Economist - i (June number, 1939). o i I t i o Meantime the construction of Nitto's Hock Wool plants has been steadily progressing. Equipment for tho production of 30- metric tons dally has been Installed at the Fukuyama plant,* the Tokyo plant, with a capacity of 50 metric tons daily, is expected to be ready shortly, and the Osaka plant is also nearing completion. * The aggregate daily capacity is expected to reach 30,000 metric tons by the end of this year. Thus far the company's rock wool products have been marketed only on an experimental basis but they huve established good reputation. A dally capacity of 100 metric tons should enable it to produce 30 ,000 metric tons ai.year on-the assumption that the plants will be operated for 300 days, and if the profit per ton is assumed to be 50, the aggregate profit would 1,500,000 annually or-an annual yield of 32$ against an investment of 4,700,000. The earnings from rock wool manufacture will no doubt improve the firm's business; and as a matter of fact the executives expsot the profit on the product to excoed 50 par ton. The faot that construction expenses for all the rock wool plants are being paid out of undivided profits makes the company* s future appear particularly bright. 3' eooo cose iich Extract from letter received from Mr. NELSON. KOBE. 5th February, 1940. y BOCK-WOOL. ( A year ago X made mention of this and in the interval a lot has been done to develop both the production and use of this substitute c material here, I enclose translation of an article on same which appeared in the "Oriental Economist" last year. This, and also the "Further Note" appended to it, were written by the President of the largest of the two producers bringing out this new material; the prospects are accordingly expressed very optimistically - particularly with regard to the expected production of 30,000 metric tons p,a. Under separate cover I send you samples of this material; Grade "A" is sold at about 15,13,-, (#62,45), and "B" at about 14*11,5,(#57,67) per 2000 lbs, I have also sent you a sample of "Millboard" made -from same. An experiment has also been made to manufacture a mixture of "Rock Wool" and Cement Into a Corrugated Tile, but the sample is not (_ worth your attention, and you will doubtless agree that this material will not lend itself to act as a substitute for asbestos in either wet or dry mixture with cement. Together with Spun Glass it will, however, find some market here, ____