Document Z4b7V0zGmVmnpN6eQ29Xv3Dzp

I JR-120Q3-R R E V . 3 -7 7 EJTMUSHEO 02 E . I. du P on t de N e m o u r s & C o m pa n y IN C O R P O R A T E D S pruance Plant P.O. Box 27001 R ic h m on d , V ir g in ia 23261 T EX TILE FIB E R S DEPARTM ENT CC: y . J. CE. J. HoIEerg J. L. McDaniel J. H. Fisher R. F. Janis, Jr. C. A. Weldon J. ?. Yuk *4 & 2 .Z -f6 > 6 0 May 29, 1981 ANALYTICAL RESEARCH MONTHLY REPORT MAY, 1981 SECTION I - NYLON-TEFLON A. FC-143 in Teflon Products - M. A. Forte, A. M. Mokhtar Objective: Establish the levels of FC-143 in Teflon products and that which can be removed under conditions of use. Status: FC-143 can be removed by aqueous extraction both in the Teflon process at the wash reel and by water extraction of "I" products. The 3odium salt form of FC-143 in "I" products is water soluble so this result was anticipated. The acid form of FC-143 is also sufficiently soluble to be partially removed from yarn after the acid bath. The data in Table I show the quantity of FC-143 which can be removed from ''I" product from a non-agitated extraction at around human body temperature. TABLE I WATER EXTRACTION OF "i" PRODUCTS @37C I&T 9450 Denier h 1ST 9450 Denier I only 9450 Denier I only 81C0 Denier I&T Kevlar Time, H rs. 2 3 64 64 64 64 ppn Removed 185 185 180 130 130 180 00003.4 SPR001427 EID715298 Section I - Nylon-Teflon - 2- May 29, 1981 The amount extracted represents, on the average, 30-35% of the available FC-143. This is an indicator of the quantity which might be transferred on handling the yarn. From the results in Table II, it appears that ^ 90% of FC-143 is removed from SM-3 regenerated yarn while v 50% is removed from SM-2 regenerated yarn. TABLE II FC-143 IN TEFLON SPINNING Location ppm in Wash Water ppm in Regenerated Yarn SM-2 SM-3 -w 1 4 490 60 The reason for the difference is the amount of washing the yarn receives. SM-3 has a wash reel while SM-2 does not. Levels of FC-143 in combined sewer were n. 1 ppm and 2 ppm for SM-2 and 3, respectively. Since yarns are heated to 'v 300-350C in sintering and ^ 100C in the induction dryer, it was desirable to know the thermal behavior of FC-143 under these conditions. The data shown in Table III are the results of a thermal treatment study. TABLE III THE EFFECT OF HEAT ON EXTRACTABILITY OF FC-143 FROM YARN Time of Heat in Minutes 10 20 30 40 N/D Not Detectable < 5 ppm % FC-143 Remains on Tarn 150C 175C 200C 75 41 N/D 72 12 N/D 72 N/D N/D 47 N/D N/D These are, of course, three possible reasons for the disappearance of FC-143. They are: Entrapment, volatilization and decomposition. IR spectra taken of the off gases indicate FC-143 decomposes. If the material i3 removed by volatilization, there could exist an operator exposure potential. Therefore, air sampling was performed in the work areas. The results in Table IV indicate there is no exposure at the 15 ppb level. 000015 SPR001428 EID715299 Section I - Nylon-Teflon - 3- May 29, 1981 TABLE IV Date 5/11/81 11 II It 5/8/81 5/7/81 Location (5) I" Production Kevlar Oven Exit " " " Entrance " Kevlar North Vent Desk North end of Machine Product not running SM-2 Wash Rolls SM-3 Wash Reel Face SM-3 177C roll 371C roll SM-2 193C roll h 371C roll Level PPB V/V ND < 15 The exhaust air from the spinning machines is water scrubbed before it goes up the stack. If the FC-143 is volatilized off of yarn, it would collect in scrubber water. Based on water volume and air flow, there is less than 0.006 PPB FG-143 in the exhaust air. Haskell Laboratory has set a 0.5 ppb provisional limit in air for FC-143. So, while it appears that there is none in the air in the spinning area, our limit of detection is 15 ppb for the air sampling done in the "I" production area. To guarantee we are meeting the 0.5 ppb limit, we plan to have a limited number of air samples quantitated at PPD in Wilmington, Delaware. Their electron capture detector is v 100X more sensitive than ours Teflon^ Cost Reduction - H. P. Tannenbaum Objective; Reduce Teflon cost and conserve bleaching cycles. Status; The area continues to operate with new bath conditions to mini mize residual zinc in yarn. This has resulted in reducing the bleaching time to 72 hours, for yarns with v 25 ppm zinc, from v 120 hours pre viously required to obtain an equivalent whiteness. Additional reduction in residual zinc to 10-15 ppm, characteristic of pre-1978 production, is necessary to obtain a 48-hour bleaching cycle. A method for determining residual zinc in y a m by x-ray has been developed to assist process in reducing and controlling yarn zinc levels. C. Potassium Bromide Specification - E. H. Dettmer Objective; Evaluate two proposed suppliers of potassium bromide against specification limits and the present material supplied by Dow Chemical Co. 00001.6 SPR001429 EID715300 Section I - Nylon-Teflon -4 - May 29, 1981 Status : Analysis of potassium bromide from Dow Chemical Co., AmeriBrom, Inc., and Morton Chemical Co. show the materials to be chemically equiva lent. The proposed suppliers are recommenced as alternate vendors of KBr. (See table attached) 000017 SPROO1430 EID715301 Specification Assay, % (as KBr) pH - 57 . Soln. Chloride, ppm Iron, ppm Manganese, ppm Calcium, ppm Sulfates, ppm (S0^) Acid Insolubles, ppm Total Insolubles, ppm Limit Min. Max. 98.5 101 -- 1000 5 5 100 - - RiOOOO m H Cfl O -j M >o o U1 o wH o to W Section I - Nylon-Teflon POTASSIUM BROMIDE CHARACTERIZATION Dow Chemical Co. 99.7 6.73 109 3 1 12 18 82 89 AmeriBrom, Inc. 100.1 6.48 12 2 1 1 20 72 80 Morton Chemical Co 100.1 5.45 12 2 1 3 20 78 85 i i i Ui i i Ni VO I VO ! oo