Document Z5rEY8GOEqageBve2z5Vq1n8

if* * 3 : ,S ' LIA1582A -r... .r^iiit.^- ... ..'- iAaisaMMaNKi-^- LEAD INDUSTRIES ASSOCIATION. INC. <> MADISON AVINUI NSW TONIC N. V. tOOtT rwi .Pimm - uu mm au ra<g_BPggggs3 vim w p p soom bameibo * . C D. tqtar Manager, Product DsvelopMBt Attrlotfi SmIUa i >tf1nirt Oo^pmf Up experience Id this field hu been ocaparatlvsly abort sad to dat a lot of It haa been rather frustrating but if 1 didn't believe there were bright ^ots on tba boriaoo, Z wouldn't ba bars, I hartan to add, however, that under no airc m stances do X wish to posa as an apart In tba Plaid. Accordingly, you may regard this talk as a bit of whistling In tha dark to keep ay oourage up, but a objective Is really to plant a pins c o m In tba Industry's cushion of ocqvlacsncy in Its chair of product develcpasat. (ter Industry has Invests! a fair sanunt. of aonay In probing tba aoouatloal flald and tbs lnatoapahla concluaico X draw fraa this work la that laid nuat ba daalgaad or aoglnaarad for tha job or It wilt oat sail. If c m. is dons with s caraful control of coats, X an oonfldant that a substantial safest far load can ba develops*. this discussion Is ooocernsd with barrlars to shat out or roduea tha trsumlo slon of airborne sound. Collateral pmKI ana not covered bara Involve tha reduction of lrpart or structural borne noise and tha absorption of sound within a roan by reducing tbs reflection of sound waves through tba use of porous e***i*?Tt1l<*1 mntsrlsls. j j Xba capacity of a barrier to block scund is stressed in decibels and la knots) as Its tranaodsalon lose or TL. The flgura as ooatrnly stated rsprassnta tba arltb atleal araraga of tha sound reduction In decibels at each of sins specific frequaoj c Im tram 125 to 4000 cycles par aoond. The transodasloo loss of a barrier raaalns constant regardless of tha magnitude or volume of tba sound. The snail wa hear la a cccpoaite of many aotfda of different wave lengths or frequencies. Tha sound spectrin la also Important to consider, for tba ear la more sensitive to high frequency sound In the speech range than tq low frequency sound, and fortunately high frequency eound Is easier to shut out than low fre quency sound. Accordingly, When Judging tha performance of a barrier. It la pre ferable to examine tba plotted curve of tbs TL for tba various frequencies tasted. To determine tha desired or required capacity or TL of a barrier, c m must consider the magnitude of the offending noise, tba background noise normally food In tba receiving room and tha degree of quiet desired by tha oecigkaat. It la obvious that barrier requlrenecrte can vary over a broad range of conditions. Presented at tha 56th Annual Meeting of tba Lead Industries Association, Id c ., Chase-Park Plata Hotel, St. Louis, Mo., April 2L-32, 1964 fMNwwiainw '1mv ipyBSinmia^Miiyisa p LIA15825 X. D. Taylor -i- Some bparlaeeej with Lead la Souad Berrien Let a* eooept for th* tin being that a barrier euob m a wall or partition la a \ typical office without air oooditimlng and where raaaonabla quiet la desired, abould anally bar* a winjam average transmission loaa of forty daelbala and that la actual practice tba great Majority of walla la modern homes and buildings fall to acct thia regnirmint, often by a oonairtsrahle aargiiu * froB the beginning It waa apparent that lead baa all tba desired proportion fbr an aomiatieal barrier, namely high density, llapnaao, good daapiag capacity, good workability, raady availability and raaaonabla ooat at laaat In tana ef lta conventional uses. It waa soon evident, however, that oonerete, gyparn block and board, dry eand, etaal cheat and other aatariala alao poaaaaa relatively high density, are lower In ooat par pound, are available around tba corner 1 noteart of allot away, and are fmiller to Boat craft man, further, tbeee ocxzaon aatariala la tba building industry aova in large quantities and at low profit aargins and. If properly in stalled, can provide satisfactory acoustical barriers. Tba specialty item la this field, however, are another Batter. They oomand aora attractive aarglas by virtao ef batter appearance, greeter convenience or oemfort, new or tmuaial physical properties, lower labor costs, portability, or any one of a Busbar of other advantages Wilch the buying public is willing to pay for. Specialty applications in ay JudgeBent are where lead Bust be Bade to fit. The Bare addition of lead to conventional walla in aoet oasaa does not ljpror* tba barrier properties sufficiently to Justify tba ooat. A prefabricated penal, however, designed for the incorporation of lead, can,Z believe, tptalify as a specialty mtarial with attractive properties. Tba advantage* listed for oonvsntiooal mtariala, though formidable, are not insurmountable. first, lead can provide wore was* in a given space than any ooo0 vectional mtarial and mass is an essential quality of a good acoustical barrier. Second, lead then properly applied baa a better natural doping capacity par unit of weight than west other aaterlale. Third, the etiffbeas of any natarlal increases by tba cube of its thickness with a result that lta barrier properties are partially offset by its stiffness through the wechinim vdilch the experts call the coincidence effect where the mtarial will readily transmit eound. In contrast, lead as a aterial can be increased in thickness froa O.dO inch to 1.0 lnebe without In curring coincidence effect in the range of sound with which ve are concerned, fourth and finally, in combination with other mteriale -- and this is fast becxmdng an age of composite aeteriala -- lead can frequently provide a better barrier at a lower total weight per square foot than other aatarlsl*. It la now pertinent to inquire as to wbathar there Is an actual basic need for iaprovad sound barriers and, if so, tfcethar thia narkat la likely to b* an enduring on*. Building construction techniques and tenant requirement* have undergone earn drastic changes in recent years and the Baselve structures of a generation ago have given way to the (lass and curtain wall closures, non-loadbeerlng interior walla, and hung ceilings. Tbs extraordinary product development work and merchandising efforts of the alvdrcp, stainless steel, glass, plastic, air oceiditicaing and in sulation industries to Mas only the leaders, have brought about changes in borne, offlee, store, apartaant end motel construction and have provided a eosplato new look to our living and working areas. This lighter construction has alao brought acoustical problame end the public clamor for tba relief la now broodly acknowledged. When the public press covers prominently the plight of a Brooklyn resident rtto at two in the morning called through th* apartment wall to his neighbor down the hail to please put on his pajama* and go to bed so the rest of th* building oould gat ms sleep, it would appear that th* aarkat for good acoustical barriers la both of oeoaidsrOl* Importance and Bagnltuda. If this doesn't oouvino* you, then th* feet that m ifru nffritmfai fc-itaP'l mmImmm9 mmmm LIA15826 . al --w-- i ip K. D. Taylor -J* Some Kqparieooee with in Sound Barrier* the occupant of another apart nmt further down the hall contributed aa Q to tha first oc^ilalnt, should do ao. 'mb ' There la littla doubt that noise or objectionable sound la a problem of in creasing iaportanc* In thla day and age. Individuals are aware of it Wien they are disturbed, annoyed or are unable to work or sleep. Landlords are aware of It whw tenant ooaplalnts necessitate aapmieive remedial acoustical work, tenants w o t s out or apace does not rent because of it. Industry is aware, of it when people refuse to w)rk in noisy areas or production slips or accidents occur because of it, or compensation ocurts grant generous awarda for bearing Imulimmit eases frequently dating back for seven1 years. Thus there is In fact a bade bsaan need for the control of aoloe. We have approached the probla of incorporating load in sound barriers in several ways: first, by testing the addition of lead to conventional materials and conventional types of construction under the HZSD program; second, by investigating in the field noise problesa referred to Hi es e result of their publicity; third, through cooperative installations asds by til using information gainsd from the XLZRO work and experimental application techniques; fourth, by direct solicitation of large potential users for introductory installations; and finally, by setting 19 our n facilities to test and rank lead bearing panels of our otm design and those of fabricators interested in this field* Older the XLZK) progrwa a nuefcer of panels ware constructed end tested by Riverbank Acoustical Laboratory. These alloyed, in various ways, lead sheets in the available wights from ^ to 8 lbs. per square foot. In this work it was demonstrated that the use of lead could isprovs the sound barrier properties of many types of walla w and panels. It also beeaas evident that the application of heavy sheets of lead to conventional walls vrould increase the cost materially. It was clear that the market mi not likely to accept such costs and that a new approach was required. Ikuing this period the BHJLS people in Australis were perfecting a leer cost continuous casting process to produce light gauge sheet lead under an TLZX) program and were testing ease in a variety of applications. Evidence began to acciaailate to indicate that two light gauge aheets might be preferable to one of equal total weight, that to be most effective lead should represent major preportion of the total weight of the panel surface to Wdch it was attached, Witch in turn pointed to the use of thinner panel skins, that the use of viscoelastic adhesive was preferable to a rigid adhesive In preserving llspness, that the use of fiber glees of mineral wool with the lead would be beneficial, that the double wall panels gave better results than aolid panels and finally that thare mist be other untried designs for ths in corporation of lssd which sight provide further Ixproremsnt within oaspetitive limits. Also during this period the L1A were Investigating various noise problems In ths field from power transformers, plastic shredders, cable machines, ticket printers, aircraft and office machine shielding, polygraph end motor test rooms, and high prasure gee reducing stations. Several successful cooperative remedial Installations have been made, the results of thick have been made, the results of Wilch bars been publicised. They typify the specialty applications refarred to earlier* A direct approach was made by Asaroo to the Tiahnan Research Corporation for nss of light gauge lead aheet as an overlay for acoustical tiles In hung oelllnge and es " an over the partition plena barrier for partitions which terminate et the hung celling in buildings ovned or operated by the parent Tlshman Realty Corporation. A test ms run on a one-pound lead sheet plena barrier between two offices in ths 666 5th Avenue building. The satisfactory performance shown in the acooepenying graphs (fig. 1 to A) resulted in authorisation for ths use of lead as an alternate We **** PW-W -plrA d r-a a M W iiim iT k 'rin i n f r iiim - t -tr~* r jrnemmuiKM % mm LI A15 8 27 emsiwit rirM>mi^mmnt-m^rimi*m'imi:ir liiimr ruimmi wmmmiSmMmilSimmmimoi X. 0. Taylor -A- ------------- -- - --------- --------------- --------------------- ----------------- 8cm feq>*rl*ne*a with Load 1b Broad Barrier*-- material for thla application la that oonpany'e Oetewey Center Building now under construction 1b Chicago. Ths X. T. Hauaaraan Company t&lcb holda tha contract for partition work In that building has currently rods an initial installation of 6000 aquara fact of ona-pound ahaat load barrier In tha bo w Cheedeal Bank hiding at 277 Park Avenue In New York City. Several othar Introductory installations In other Major new buildings are pending. In thla application load as a Material la Mora ajq>*neive than gyparo board bet la aaaler to cut, fit and Install, thus providing a no ra effective barrier. In eocparlaon with an aludnua foil-asbestos paper-fiberglass barrier, eoa-pound lead ahaat is easier to fit and la half tba oost par square foot. This Market will not just drop in our lap. Architects and applicators mist be taught bow to apply it properly and thla will require oonatant follow-op to gat It established. The partition Industry is variously estisted to be a $100,000,000 business. At $10 par lineal foot, there would be 10,000,000 llnral feat annually. With, 'ay, lfljf of tha partitions requiring plena barriers, this would represent 1,000,000 feat of lead sheet 2-3 feet wide or 1000-1500 tons annually. Tbs partition Market would obviously be even Mora attractive if low cost, affactlva panels can be designed. With this objective in Bind, we have Installed In our laboratory at South Plainfield. Row Jersey a sound test facility to permit us to Make noise reduction determinations on standard A' x 8' panala or walls up to 9 feat wide by 8 feat high If desired. We are interested only In ranking various Materials and panels by performance and coat. \.`e are not in competition with comaereial eooustleal laboratories. w The facility consists of a source rocs 9' wide by 8'A" high by 12*6* long, laaide dimensions, and a receiving room 9* by 8'A by 15', isolated froM each othar by a i" saw cut through the floor and sialtar gaps In tha celling and elds walla tdilch have been stuffed and ceulkod, constructed of 8" solid concrete block eoccopt for the ccaoon dividing test well which is Made up of two sets of panels comprising 8 pound sheet lead on 2* * J" wood frames backed with fiberglass and placed bade to back with i Inch of free air space to provide a test wall 8 Inches thick with a tranamiseion loss of 65 decibels. This was built, equipped, for leas than $7500. A A' x 8' section of a ccanerctally available stael partition system, rohnd ylng tbs normal ports, joints and fittings, was Installed In our test wall by tba vendor. Oir test results in the as-installed condition fall slightly below tha Manufacturer's published TL data but, after carefully plugging all leaks, our test results ecagmr* closely with his and at several points exceed them. The neat Move is to endeavor to affect an Improvement through the application of lead to his existing design or to modify it so as to permit an improvement to bo obtained. In the seme vein we have endeavored to build up lisp penal cores using erne pound sheet lead as e basis for lsproved panel design. The results are certainly not conclusive but, by the aaaa token, they are anoouregirg, for example, In figure 5 we have plotted the nolee reduction values* la decibel* for a single sheet of one pound lead and than for two lisp aheete with varying space between them. The curve for on* pound lead Is a typical one and approximates the theoretical nasa law curve. The addition of a second abact with 0 J*an air space of 1 5/8" show* Barked iaprovanent. Increasing the air epee* to 3 gives further attractive improvement. five Inches of air space, however, adds little except at low frequencies and la hardly worth tha apace required. njjjBMuiinaj j m'h s aji-s impjii > --A**., T]- LIA15829 we.aar.... i K. 0. Taylor -5- Sooa &q>arlaoe* with Lead la Sound Barrlar* figure 6 above two ahaata of load 1 5/8" apart and tha affact of adding 2" of fiberglass to tha air specs. Tba iaproveoent hara la Intriguing. A thin bardhoard skin addad to tba aourca rooo aida In almlatlon of panel construction adda aararal decibel*. Another akin of hardboard on tha race!ring room aide unfortunately oould not ba placed anugly against tba lsad core aheat so in this caaa tba additional air dead apaca baa oontrlbutad acre iaproramant than tha akin. Bear in Bind that this panel was put together in aitu and doaa not ropreeent tha equivalent of a pre fabricated panel. It praaanta only an attractive objective of clothing an effective oore aaseahly with a fraaa and skins in such a manner aa to maintain ita barrier properties, and to provide an attractive and durable panel at low coat which can ba easily Installed by anyone. 1 regret to advise that we do not yat have tha answer to this phase of the problast, figure 7 ahowe a similar treatment using 2" of fiberglass in the 3ja air apnea and adding * plywood Instead of 1/8* hardboard. lb**#'curves seen to Indicate that little is gained by increasing the panel thickness and parhapa tba plywood stiffness is rsduelng tba barrlar capacity at low frequencies. Perhaps it is unwise to exhibit euch curve* before obtaining a finished pro duct with documented substantiating field performance data. X prefer, however, to take the gsable for if \m can retain a major portion of this barrlar capacity In a prefabricated panel, than wa shall have something attractive to offer to a narkst of eoosiderable amplitude. Vs Invite you to loin ua In this effort -- that Is, if you era strung of heart and yowg in spirit. 4 4 *VB values determined in any given teat facility are fully cooparehla with one another and approxiaat* TL values, tut they mat be adjusted for the absorption characteristics of the recalvirg rooa to be classed aa n, values. ijueuww.^-ue1 uiviwupML^vaigp nsrt mmmm