Document 19YxgyvRrMJNKOZDDG32jEqo

LEAD INDUSTRIES ASSOCIATION 6I It! MADISON AVKNUC NEW YORK 17, N. V. * . August 24, I960 SUBJECT! REPRINT FROM ----------- 3T33THC5XZINB To Merbera of the Lead Industries Association! We believe you will be Interested In the attached reprint of an article vhich appeared In the July 25th issue of STEEL MAGAZINE, relating to the use of lead as a sound and vibration barrier. The article vas prepared by Mr. Brian Wilson of the magazine's staff, with the cooperation of L.I.A. and others Interested In the subject. Sincerely yours. U/*-' A------ - Secretary / / (y iw iiiii U>pi m JW1--'j-ffwawiwjui ' --wwB>wiwyfj LIA24329 0 Mb K Shakes, Rattles, Roars ... Lead Loves Them LEAD people hope to develop an important new market out of shakes, rattles, and roars. They know they have a good thing because the control of sound and vibration Is becoming increas ingly vital in many areas. In archi tecture, for example, the move to ward airiness and (hr open look has created a new set of problems. And the need for noise and vibration control has been accentuated by greater use of complex equipment in the home, office, and factory. How It Works--Watch how a sponge sops up water, and you*11 see just what happens when high fre quency sound or vibration comes in contact w ith lead. Technically, this Is known as internal damping (sound Is converted into heat cn- *ncy). When sounds and vibrations of tow frequencies (the kinds that bother human ears) contact lead, twt> things happen: Part of the sound is absorbed as in high fre quencies, the other part bounces back-similar to a letmis ball hit ting a wail. It moans that lead forms a barrier which effectively denies passage to sound and vibra tion. Lead's antisound and vibration qualities are due to two metallur gical traits: It's limp--like a wti dbhcloth, and It has high density. Both characteristics are necessary in a good sound and vibration damp ing material. Those properties have been known for years, but real Interest In the application is recent But It now looks like a msfor break through in use may be In the mak ing! R. L. Zicgfeld, secretary of the Lead Industries Association, reports that his group has had more in quiries for information in the last six months than in the previous 20 years. Requests for data on leadasbestos antivibration pads alone have hit 1000 in the last six months, and they're currently running at a rate of about 45 a week. "For the first lime, designers and engineers in general are thinking of tend as a sound and vibration con trol material," says Mr. Ziegfcld. Where Lead Is Used -- Small amounts of lead now going into sound and vibration control fall Into three categories: 1. Lead-asbestos pads. 2. Sheet lead and laminated plastics. 3. Leaded plastics. By far the biggest market Is in lead-asbestos pads for vibration con trol. One such use is in building foundations to prevent transmission of vibration from the ground into the structure. The recently com pleted, 54 story Union Carbide Corp. building In New York City has 115 such pads Incorporated in the foundation. They'll also be used in Grand Central City, said to be the world's largest office building. (It's scheduled for completion In 1962.) So will the Philharmonic Mall at the Lincoln Center for the Performing Arts In New York City. (It's under construction.) Probably the biggest potential for lead-asbestos pads is In roof top cooling towers for commercial air conditioning equipment One of the first installations was on ft 35 story office building In New York. The cooling tower, with a wet weight of 205,000 lb. Is supported v/n ten tiiJ ngle columns resting On the building! v'*'* *tn*rtnr*| girders. The tower's posts rest on ten lead-asbestos pads which pro vide an antivibrttion bearing sur face of 928 sq in., or about 220 psL The air conditioning field holds promise of becoming a 50,000-ton-a- year market for lead, says Mr. Zieg fcld. The potenti*1 bright for antivibra*'^*! pads In cenwol t%ome conditioning, he believes. Ofh<T use*, current and potential; All types of heavy machinery com pressors, printing presses, laundry equipment. Sound Barrier*--The potentials for lead in sound control may be even greater than they are for anti vibration applications--though the arcs Is less explored and less devel oped. When the vibrations created by a loud noise come In contact with lead, they are unable to pass through. As one lead man puts H: "It's like trying to ring a bell hi mashed potatoes" Short lead has been traditionally used in this application. For ex ample, the studios of the National Broadcasting Co. in New York hove 112 doors that are soundproofed with 0.0625 in. sheet lead. Now it seems that lead in combination with plastics offers the versatility that could open a full scale market. Currently, the most promising of the load-plastic combinations ap pears to be the leaded vinyls. Cordo Chemical Co., Norwalk, Conn., one of the pioneers In the field, ex plains that the product consists of lead powder dispersed In i vinyl and then coated to a fabric. The product run* 66 to 75 per cent lead by weight and can be colored and embossed, says Fred Hall, Cordo sales manager. The Llggcst immediate potential appears to he in building products. I.cad researchers mention such pos sible growth areas os movable par- ,\ N 2034.01 j iij iiu .ih <3! ii ILfiUliiiJltMlIS.MWSUlMBWMaam***^^^ LIA2A330 k Vati* 11 r tea Am a# titionv, ceiling materials, Hiring, doors, windows portable space di viders and air conditioning duels. One of ihe beM prospects is busi ness machines says Mr. Mali. He also mentions machinery surface's; small spot applications (like a noisy part on an appliance). The Navy has been experiment ing with a number lead com pounds for hull damping on some of Us new' ships. Applied to the inside of the pressure hull, the ma terial keeps vibrations from affect ing sonar cspiij nent. The same t)|>e of material might be used in maihinery housing to control sound vibrations, bcliesc industry people. Also mentioned: A lead spray for machinery shrouds and housings. Lark of Data--A lack of test and performance data for engineers and de-signers has been a major stum bling block to wide scale acceptance of lead's usage as a sound and vi bration attenuator. Frank Kiernan, treasurer. J. F. Abemethy & Co* Brooklyn (a lending maker of lead- asbestos pads), says that when suf ficient data arc available **we will have a tremendous potential in U types of machinery.** Projects have been launched to get basic data and to develop proto type lead-contained product*. Say* MA'i Mr. Ziegfeld: "We expect that by 1%5 the tonnage market for lead in sound and vibration control will be in five figure*.** About a dozen companies are manufacturing lead-based product*; perhaps another two dozen are set to enter the field. Reprinted from STEEL July 25, 1960 CwM iteO te n* <*. CW*ite <1 OMt 1 *X *- mrn^j j .u w j 1 Av