p. 1



# OAR Box 1313 Preppedby LaTeiaShed



### Document

Number: 

# 17 ) l-B-1 0
Docket Number: 

# A-88-0 2

Printed 6/12/20089:03:27AM

Sheet 17 of 99P. 2 

# ® MIDWES T RESEARC H INSTITUT E -;-r.~>; ii. UBS H 450 5 Creedmoo rRoa d Raleigh , N.C

. 2761 2 Telephon e (919 ) 781-575 0 

## A-88-0 2 x-fe-i o 

# FIL E COP Y

Date : Februar y

21 , 198 6 (Finalize dMarc h28 , 1986 ) Subject : Sit e Visit—Lufkin ®

Chromiu m Electroplatin g NESHA P EPA Contrac t 68-02-3817 ; ESE D Projec t 85/02 a MR I Projec t 7717- K 

# i W From : Rand

y Str a To : Al Vervaer t

ESED/ISB/SS S (MD-13 ) U . S . Environmenta l Protectio nAgenc y Researc hTriangl e Park , N.C . 2771 1

I . Purpos e Th e purpos e o f thi s sit e visi t wa s t o gathe r informatio nabou t th e electroplatin g o f plastic s an d th e us e o f a trivalen t rathe r tha na hexavalen t chromiu

m electroplatin g bath . II . Plac e an

d Dat e Lufkin® Pos t Offic e Box72 8 Apex , Nort hCarolin a 2750 2 (919 ) 362-751 1 Decembe r 19 , 198 5 •i\]\) III

. Attendee s 

### JA N 

### I 8199 | 

# LM^M ^l^E^l^ociirf j Ray Blakely , Engineerin g Manage r Mat t Caton , Environmenta l Enginee r Georg e Whitesell , Chie f Chemis t Midwes t Researc hInstitut e Charle s Heste r Randy Strai t U . S . Environmenta l Protectio nAgenc y Cynthi a Dowd-Monroe , SD B Al Vervaert , IS B

/ Principa l Laboratorie s 42 5 Volke rBoulevard , Kansa s City , Missour i 6411 0P. 3

IV . Discussio n W e arrive da t th e plan t a t 9:0 0 a.m . Th e visi t consiste do f a discussio nabou t electroplatin g processe s operate da t th e plan t an dth e basi s fo r thei r selection . Th e discussio nwa s followe db y a complet e tou r o f th e plant . A . Genera l Lufkin®i s a divisio no f Coope r Industrie s an dproduce s a variet y o f cloth , wood , an

dstee l measurin g tapes . Lufkin®operate s two decorativ e chromiu m electroplatin g lines . On e lin e contain s on e hexavalen t chromiu m bat han di s use dt o chromiu m electroplat e high-qualit y stee l surveyo r tapes . Th e othe r lin e contain s two chromi c aci detc hbath s an da trivalen t chromiu

m bat han

di s use dt o chromiu m electroplat e acrylonitrile-butadiene-styren e (ABS ) plasti c case s fo r 10-foo t stee l tap e rules . Abou t 2 year s ago , Lufkin® replace dthei r hexavalen t chromiu m bat h wit ha trivalen t chromiu m bat ho nth e AB S plasti c cas e lin e bot ht o reduc e wastewate r treatmen t cost s an dth e numbe r o f rejecte dpart s (scrap) . Th e conversio nwa s accomplishe da t a cos t o f approximatel y $100,000 . Th e trivalen t chromiu

m bat hi s a proprietar y solutio nsol db

y Udylite ®unde r th e name TricrolyteTM . Th e plasti c platin g lin e average d3. 9 percen t scra p whe nusin g th e hexavalen t chromiu m bat han

dnow average s abou t 2 percen t wit htrivalen t chromiu m bath . Plan t personne l state dtha t the y hav e encountere dsignifican t problem s wit hoperatin g th e trivalen t chromiu m bat hdu e t o it s comple x chemistr y

an dsensitivit y

t o contaminants . Discoloratio no f th e case s occur s whe nth e coppe r conten t i nth e bat hreache s 8 t o 1 0 part s pe r millio n(ppm) . Whe nLufkin®bega noperatin g th e trivalen t chromiu m bath , th e scra prat e range dfro m 1 0 t o 1 2 percen t becaus e o f coppe r contamina tion . Th e coppe r conten t i nth e bat hi s no w maintaine da t wel l below 1 0 ppm . I naddition , frequen t addition s o f ammoni a t o th e trivalen t bat h (~ 2 gallons/day ) als o ar e neede dt o regulat e th e pH . Althoug hth e wastewate r treatmen t cos t fo r trivalen t chromiu m i s somewha t les s tha nfo r hexavalen t chromium , th e require dadditio no f ammoni a t o th e trivalen t bat hha s offse t som

e o f th e cos t savings . Hexavalen t chromiu m i nth e bat h als o i s considere da contaminant . It s presenc e i nth e bath , eve ni n negligibl e amounts , cause s discoloratio no f th e plate dparts . Althoug h hexavalen t chromiu

m i s forme di nth e platin g process , it s presenc e i nth e bat hi s controlle db y th e additio no f a reducin g agent . B . Proces s Figur e 1 i s a flow

diagra m

o f th e AB S plasti c cas e platin g line . Th e case s ar e loadedmanuall y ont o rack s a t th e firs t wor k station . Part s ar e place dint o .tw

o chromi c aci detc hbath s wher e th e surface s o f th e plasti c case s ar e etche dt o increas e adhesio ncharacteristics . Th e firs t etc htan k contain s a solutio no f 5 8 ounce s o f chromi c aci dpe r gallo n (oz/gal ) o f water , an dth e secon dtan k contain s 5 4 oz/gal . Bot htank s ar e



### J?.Figur e 1 . AB S plasti c cas e platin g line . 

# 3P. 5

maintaine da t a temperatur e o f 150°F . Sid e draf t hood s ar e use dt o provid e ventilatio naroun dth e tanks , andUdylite ®fume suppressan t i s use dt o reduc e dragou t an dmistin g a t th e surfac e o f th e tanks . Afte r etching , th e part s g o throug ha serie s o f seve ncountercurren t flo w rins e tank s fille dwit hwater . Afte r rinsing , th e part s ar e place di na n"activator " tank tha t contain s a combinatio no f palladiu m an dti ni nsolution . Th e activato r solutio ni s use dt o fil l crack s an dvoid s i nth e surfac e o f th e AB S plasti c case s andt o provid e a conductiv e surface . Two countercurren t flo w rins e tank s follo w

th e activator , an

dthe nth e part s ar e place dint o anaccelerato r tan k wher e exces s ti ni s remove di na dilut e hydrochlori c aci dsolution . Thi s proces s i s followe db y two mor e countercurren t flow rins e tanks . Th e firs t platin g bat hi s anelectroles s nicke l bath . Th e nicke l bind s t o th e palladiu m an dprovide s a hard , durable , an dconductiv e surface . Followin g tw o countercurren t flo w rins e tanks , th e part s ar e place di na coppe r sulfat e tank tha t add s a thi nlaye r o f coppe r t o th e surfac e o f th e cases . Afte r furthe r rinsin g i nfiv e tanks , th e case s ar e place dina long acid-coppe r electroplatin g tank . Th e copper-plate dpart s the ng o throug hthre e countercurren t flow rins e tanks , anothe r activato r tank containin g a hydroge nperoxid e an dsulfuri c aci dsolution , an dtw o mor e countercurren t flow rins e tanks . Th e brigh t nicke l electroplatin g tank the nprovide s a durabl e nicke l surface . Afte r thre e countercurren t flo w rins e tanks , th e case s g o int o th e trivalen t chromiu m electroplatin g tank . Followin g th e trivalen t chromiu m electroplating , part s ar e rinsed , dried , an

dunracked . Th e rack s the ng o throug ha chromiu m stri p(causti c sod a solution ) an

da nicke l stri p(nitri c aci dsolution ) fo r cleanin g prio r t o startin g th e cycl e again . Stee l surveyo r tape s ar e plate do na continuou s platin g lin e (Figur e 2 ) usin g a conventiona l chromi c aci dplatin g solution . Th e hexavalen t lin e i s muc hsmalle r tha nth e trivalen t line . Eigh t stee l tape s ar e unwoun di nparalle l fro m eigh t larg e spool s a t th e beginnin g o f th e process , ar e pulle dthroug ha serie s o f rins e tanks , a nicke l electroplatin g tank an dth e hexavalen t chromiu m electroplatin g tank , ar e rinse dagain , drie di nanoven , an drewoun dont o spool s a t th e en do f th e platin g line . Th e hexavalen t chromiu m platin g bat hcontain s 3 3 ounce s o f chromi c aci dpe r gallo no f wate r an di s operate da t 6 volt s an d 42 5 ampere s o f direc t current . Th e bat htemperatur e i s 112°F . C . Emissio nContro l Th e trivalen t chromiu m tan k i s ducte db

y sid e draf t hood s t o an evaporato r (manufacture db y Headie ) tha t i s use dt o reduc e th e volume o f th e liqui dbefor e i t i s recirculate dt o th e tank . Exhaus t ai r fro m th e evaporato r goe s int o a singl e packed-be dwe t scrubbe r (manufacture db y Viro nInternational) . Th e airflow rat e o f thi s system i s 2,80 0 standar d cubi c fee t pe r minut e (scfm) . A nadditiona l demiste r (manufacture db y Kimre ) wa s installe dafte r th e scrubbe r t o improv e mis t elimination .

/P. 6



# ILL I
j\i^ £

R»U5 t

Ai'iCK£< -

rt J

. - 

## f

CHT^CAt t

H-C T NI(«S £ . _ * V'EN T

.-4 , ve^"* "

_ _•i/in-r


# r m

Figur e 2 . Stee l surveyo r tap e platin g line .



### O .P. 7

Th e hexavalen t chromiu m electroplatin g tank o nth e stri pplatin g lin e i s vente d(8,00 0 scfm ) t o a singl e packed-be dwe t scrubbe r (manufacture db

y Viro nInternational) . Ai r fro m th e platin g shop s an dal l tank s othe r tha nth e trivalen t chromiu m platin g an

dhexavalen t chromiu m etc htank s i s ducte dt o a commo n exhaus t system . Th e airflow rat e o f thi s syste

m i s 38,00 0 scfm . D . Conclusions Th e trivalen t chromiu m electroplatin g lin e a t Lufkin®i s well-designe dan

d-operated . Plan t personne l expresse dsome dissatisfactio ntha t th e trivalen t system ha s no t resulte di nth e magnitud e o f cos t saving s the y hadanticipated . Afte r anextensiv e startu pperiod , th e scra prat e ha s bee nreduced ; however , wastewate r treatmen t cost s hav e no t decreased . Chromiu m emission s fro

m th e platin g operation s ar e controlle db y singl e packed-be dwe t scrubbers . Udylite ®fume suppressan t i s use dt o contro l emission s fro m th e chromi c aci detc htanks . Th e etc htank s ar e ducte dthroug hanexhaus t system tha t als o handle s exhaus t ai r fro m severa l othe r operations . Althoug hemissio ntestin g i s possible , i t i s no t recommende da t thi s time becaus e o f th e lo w hexavalen t chromiu

m usag e rat e an dth e dilutio no f th e exhaust s from th e chromi c aci detc htanks . However , plan t personne l ar e cooperative , an dfurthe r exchang e o f informatio nma y

b e beneficial . Plan t personne l agree dt o provid e th e informatio nrequeste dinth e attachment . Attachmen t



# £Fo reac h chromiu m platin g tank , pleas e provid e th e followin g infonnatio n (cit e typica l value s rathe r tha n range s fo r operatin g an d productio n parameters)
.

1 . Dimension s o f tan k 2

. Concentratio n o f chromi c acid , oz/ga l 3

. Catalyst(s ) use d Plasti c plate r Plasti c etc h Tan k 1 55-1/4 " x 22-1/2 " x 6S-1/2 " 5 8 Udiqu e 85 7 Tan k 2 55-1/2 " x 94-3/8 " x 65-1/2 " 5 4 Udiqu e 85 7 Plasti c plate r trivalen t chromiu m 55-5/8 " x 46-1/4 * x 65-5/8 "

Tricrolyt e catalys t Stri p plate r hexavalen t chromiu m 36 " x 48 " x 66 " 3 3 Hone

20-2 5 dyne s /c m
15 0 4

. Concentratio n o f catalyst(s) , measure db

y surfac e tensio n 5

. Temperatur e o f platin g solution , ° F 6

. Operatin g voltage , volt s 7

. Operatin g current , ampere s 8

. Thicknes s o f chromiu m deposited , in

. 9

. Platin g time , min/rac k 10

. Hours o f operation , h/d ; d/wk ; an d wk/y r 8 ; 5 ; 48 11

. Percen t o f operatin g tim e electrode s ar e energize d 12

. Productio n rate, * cases/y r fee t o f tape/y r 3,250,36 9 case s 342,000 othe rpart s 20-2 5 dnyes/c m
15 0

Sam e <3 2 dnyes/c m

7 5 1 2 1,60 0 (depend s o n siz e o f case ) Unknow n 4 minute s

8 0 percen t

Sam e 112

550

1 0 millionth s

8 ; 6 ; 4 8 100 percen t

15,697.83 9 fee t

*198 5 productio n rate

.

N l