Document jBV9mxOwj0bBMOjdgj9GK7vpR

\-Z` 23 on visi* to ,. - t > 1 ^-----e-~ or. * K <3 n ' -ar.i December 11, 13.. 4 ana to the : ultibes :s J.-- er.",* Valpole, on November 28, 1934. c By: E. 3. Elkins Officials ret: 1 *1. Egan Leach Hr. Edwards ' 'y* P.css * fv* Jensen Taggart (cuief chemist) (plant manager) ?.br. VcHcriie Vjt. Bateson Ur. Slagle Ur. Martin l!r. Hears Hr. Stowe L The more important contacts are underlined. Kota: Du9 to the nature of its business many of the processes of this corn.any are unioue. I teas which it is believed mey not be general practice are marled with an as ter is-, and should be treated as conf idar.tial until passed upon by an official of the :ompany. The Dewey and AT-y Chemical Con"any manufactures primarily latex tenants and allied products, such es sclv r.t rubber cenent3, rub'berized fabrics, and ruotar- bonded brake linings. It was because of their developments 'n this last field that they ac paired the Multibustos Company, which manufactures brake linings arc clut: . facin.rs of ell typos. c Dewey and DLmy Company Hr. Juan she /ed me about the plant in 0 em.br id re. lotan cements: Rubier later, is obtained ir. solutions containing 35, 6C or "z per cent solids. In the 'ilute solutions there is about three fourths of a per oent of ammonia, which leaps the solution at a pZ o*' 11, and so r revent = fermentation ard spoilage. In the most ccr.cent-aced scluti.ns the alkalinity is maintained by a mixture of caustic gotesh and e potass man occasr.ut oil soap. Armenia is preferable for -tost pu.-- oses because it eva.orates off. Its concentration is so low that it is no problem exce_ t .7hen t,,e cement or comound is used in very large quantities. 'Various materials such as oigner.ts and "illers ore added to the late:: solution in making tr.e oom..ound. One such material is e modifying soap made from be'swe:: and arm. on la under high pressnre. Sulfur is added whenever it is desirable and ocssible to cure the rubber in the cement or other oroduot. In tr.e linings for tin cnr.s sulfur can not be used but fortunately an uncured notarial is more satisfactory. tct many ourposas a latex cement is inferior to an artificial rubber emulsion, made by masticating- vigorously coagulated rubier end then dispersing it with protective colloids end othe^ 3uit -ble chemicals. A cement of this type se-mad much finer and more homogeneous than corresponding latex cements, and its L cost was said to be the seme. Latei caments are of Interest to U3 because they cdmxete vi tn solvent rubber cements. One of the chief uses of benzol is es a solvent "or toe letter. Jor sene our cses non-toxic non-Inflanmabla latex cenents ore better substitutes for toxic, inflemnble benzol cenents than th: slightly toxic but lr.fltenable neotha cenents. Lir. Terguson said thut there had been a spirit evay fron latex sealing contounds toward solvent compounds, but that he felt thet its peak had passed and the immediate future would see an increased use of the latex oroduots. Solvent room: This cor., any raise both benzol end naphtha solvent cenents and con- pounds. The letter constitute about two thirds of the total, and it was seid th. t probably next yerr three quarters of the solvent conpounds would be made fron naphtha. The so-ctlled solvent room is the second .''loor of an isolated building. It is -bout 23' x 12' x 8', and contains two nixers, "or naphtha end benzol products, rsr. actively. Each nlxer holds about e hundred gallons. Zxoosure to the solvent may occur chiefly in three pieces; the pump roe-., the solvent room, anc oxddlsr r~om, in .vhich the finished cenent is loeced into lrur.e for shipment. In *he pump roam there is some leakage of vnpor, or seemed to be, but the pumps ar9 operated from outside, and the room is rarely entered. In -'illing the drums there is undoubtedly some exposure, but the greatest hazard is carteir.ly in the solvent room. The solvent is ordinarily unped through a meter into the mixer. The stirrers ere hcevy spiral shaped knifes vhich twist ar.d tear the small c pieces of r'"ber which are introduced. Scr : heat is evoi-ed in t"is operatic: sc :h-t the camp :r\ bur? -)" the mixture is raised, t-.a outside of the mixer being tbov. hody temperature when the process v:s observed. The mixers ar9 closed exca t "or art opening in the too '-bout 18" x 1C" which is covered loosely ON*-** " * ^ rials =re bevg and d, order, the butch is ceing in- , rr.d .ner. it is b e inx am t i e d . The rdditirr. of rubber (cut in small pieces) taxes seme time, es the several lay rs are torn apart by hend or they ere fed into the machine . home other m.-t-r -els, s' oh as max, arc usuflly ad led. Ir. the or-retion observed insoectio: s of tie batch as it was being mi men m--ere freguer As the to of tn.e mix-.r is about five feet from the floor the ardency is for the vorhr.au to put his f'.ce close to toe opening in L.o-cin; in at the batch. After two to eight hours, deper.din. chiefly on the kino of rubber use-1, th e mixer is tipped on its side and t.ie batch of finished prodir t is dumped t hrcugh an opening in the floor into the muddler. The lumping operation obs erved took four minutes, including t.ie ti:..e required to rake out the residual c tmtwuni . The opening at. the mi.cer through which the substance is poured is about thr9e feet from the floor, and the operator stands three to four feet eway exc e 7 * when he is cleaning out the resizue. The extremely viscous and elesv ? meas /es said to contain only thirty per cent of solids. Its vapor pressure would presumably be a preciably more than 70 per cent of that of pure benzol, but the viscosity of the mixture ohnull cut iovn its rate of evaporati sidorably. L A bl.-er 3 oaerotiny ir. the wall oapetite the mixbr, nec_r tee ''loom, and above it the wi.v.ow wps opened. The operator was between the winocw : r.d the miner, but a little to one side .test of the time. The efficiency of tnis system of ventilation seems somewhat questionable. Tests on the elr in this roots (made by the insurance company) showed satisfactory conditions, however, it was said. The men wording on this Job are river, blood counts every three months end as a rule are transferred after six to nins months. Ko real cases of benzol poisoning have oeen encountered. AR. dope: This impregnating material is a mixture of about five parts coal tar pitch end one part toluol. The components are heated in mixing, and ventilating equipment has been ordered for the process. The fumes did not seem bad at the time a finished bates, was observed in the open mixer. Rubber bonded brake lining material: dertein bra_e linings, especially those for heavy work, are made from asbestos to which carbon black and other substances may be added, and rubber latax. The various materials are mixed in a peter beating machine, spread on a wire screen and the water sucked out, then pressed in a hydraulic press, cured and brtught to the proper thickness with a sanding interim. The last operation is well vontiloted, but the method of feeding the paper better was said to be dusty and needs improvem/nt. Probably some such method'as was worked out at Talpcle ,ili oe applied hers. None of these processes were ir. operation. -ArtificaL le-ther: A soft absorbent p-;sr is parsed thr-uph a later oaf - tion containing c sulfur, colc.-'.rr m=**.r, stt., end then amr a scries o' heated rolls where the rater era ammonia are giver o-'f and the robber is cured. An exhaust system - ,, ~ wriddJes for f 3 removal of ale ammonia given off (estimated at thre cci :s. or about 3! . jr .tour, \ ach 0: `he r.ec.as: rry : stop the mac'line f:r brief ooriods in order to . , .> _ - - ,, !* "'-a - s temos to tisi: i - V. rise; ms in -.;elitv in the finished material. The r"bherii-rd sh'et is au-red `'.rcuch a celonder tc brin, it to t .riper tr.i akr: :a. T: or m.:r. shj3ts -arc ;:'ter a jr.-ante:' toyrtlar, srreti es : o or : r -e r: i' V - r.m combined cr. a mr chine similar to the impremr.,,ting :'i r.a. hut smaller. !To provision for the removal of irancnia is n': ir. this oe, but there was no epame iuble odor of arvrr.ia around the machine. If still thideer sheets or; to ve nude, pieces ubj--` five 'jet sqitre arc cemented together by hand. Ir. the operation observed a naphtha s-lvart c ?-ant was 'toed. Other products: Soda '.'me, used in mas masks for absorbing phosgene, chlorine and acid gases, is n.ie in some quantity. Zinc chloride solutions and tine ammonium, .-'lirioj crystal.: ore also mace. Some dermatitis has bean caused by these mat trials. L P- tl "wV**I..^ -s' - w* -- i toluene are used .'s preoeerr77i.ot:7es. uarbo c chloride i3 also used or some purooses. koparently these are use atively small amounts Another small use of benzol is in cleaning ou` drums. c