P. 1


# OAR Box 1500 Prepped by Ollie Stewart



### Document

Number: 

# 1 ) ll-C-2 7 Docket Number: 

# A-94-5 2

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# 1532 . UNITE D STATE S ENVIRONMENTA L PROTECTIO N AGENC Y RESEARC H TRIANGL E PARK
. N C 2771 1 OFFIC E O F AI R QUALIT

Y PLANNIN G AN U olMIVBHWS"" " Novembe r 7 , 199 5 Dea r Tea mand/or Wor k Grou p Member : . *rJ&W!!<^•^4y^y?"t tK •^yf•••^'^ 

### DE C 

### 3 5 - % > EP A /U R DOCKC T •* * s I a mforwarding acop

y of adraf t "Pollutio n Prevention/Sourc e Reductio n Measure s Memorandum " to th e trade associatio n member s an d other s wh

o hav e volunteere d to revie w it . Thi s memorandumcontain s information on the variou s pollutio n preventio n technique s whic h ca n b e use d t o reduc e emission s i n th e reinforce d plasti c composite s sourc e category . I f anyon e els e woul d lik

e t o revie w thi s memorandum , pleas e contac t m e a t (919 ) 541-2383 . Sincerely , AcMadeleine Stru

m Environmenta

l Enginee r Coating s an

d Consume

r Product s Grou

p Enclosur eP. 3

Addressees : Mar k Banner , RTI , w/Enclosur

e Moha n Balagopalan , SCAQM

D (Electronically sent

) Janet Beloin , Region I (Electronically Sent ) Bo b Burmark , Washington DO E (Electronically Sent

) Nei l Carman , Sierr

aClu b (fo r Be n Pamar ) Leonardo Ceron , Region I

V (Electronically Sent

) Lind aChappell , OAQPS/AQSS D (Electronically Sent ) Patrici aEmbrey , OG

C (Electronically Sent

) Bo b Fegley , OR

D (Electronically Sent

) Chuc k French , OAQPS/AQSS D (Electronically Sent ) Lind aHerring , OAQPS/ES D (Electronically Sent ) Nor mKaplan , OR

D (Electronically Sent

) Emer y Kong , RT

I Kare n Levy , OPA

R (Electronically Sent

) Mari aMalave , OEC

A (Electronically Sent

) Hail e Mariam , OSW (Electronically Sent ) Crai g Matthiessen , OSWE

R (Electronically Sent

) Stev e McNally , Composite s Fabricator s Assoc , w/Enclosur e Christin e McPhee , Ohio EP A Arnol d Medbery , OSDB U (Electronically Sent ) Richar d Nielson , Clar

k County , N

V Carlo s Nunez , OR

D (Electronically Sent

) Nanc y Pate , OAQPS/ITPI

D (Electronically Sent

) Solomo n Ricks , OAQPS/EMA D (Electronically Sent

) Ro n Ryan , OAQPS/EMA

D (Electronically Sent

) Joh n Schweitzer , Composite s Institute , w/Enclosur e Jorda n Spooner , OPPT/PP

D (Electronically Sent) , w/Enclosur e <_

_P. 4

DRAF T MEMORANDU

M TO : Madelein e Stru m U.S . EPA/ESD/CCP G FROM : Gre g LaFla

m Pacifi c Environmenta

l Services , Inc . (PES ) DATE : Octobe

r 23 , 199 5 L:\N30 8 SUBJECT : Pollutio n Prevention/Sourc e Reductio n Measure s Thi s revise d memorandu

mon pollutio n prevention/sourc e reductio n measure s fo r th e plasti c composite s sourc e categor y i s bein g submitte d i n respons e to tas k 1 i n Wor k Assignmen

t No . IV-4 . You

r comment s on th e Septembe r 25 , 199 5 draft , a s well a s th e suggestion s yo

u mad e by telephone , hav e bee

n incorporated . Pleas e notif y m e i f yo u would lik e an y additiona

l change s made . [Additiona l changes are indicate d i n redline , strikeout o r bol d —M . Strum ] 4. 0 POLLUTION PREVENTION/SOURC E REDUCTION MEASURE S 4. 1 RESIN S 4.1. 1 Lo w Monome

r Conten t Resins/Ge l Coat s Traditiona l genera l purpos e orthophthali c (ortho ) typ e polyester resin s hav e histori

cally containe d approximately 4 4 t o 4 8 weigh t percent styren e (o r

styren e an d other

HA P monomer ) conten t b y weight . B y th e mid-1980' s dicyclopentadien e (DCPD ) resin s wit h a lowe r monome r conten t wer e i n us e fo r certai n applications , but

generally produce d product s tha

t wer e mor e brittl e and lowe

r i n strength . I n 198 8 th e Sout h Coas t Ai r Qualit y Managemen

t Distric t (SCAQMD ) i

n Californi aissue d Rul e 1162 , which provide s anumbe r o f contro l option s includin g a n uppe r limi t on th e monome

r conten t (afte r filler s an d additive s ar e take

n int o account) . Severa

l other area s hav e implemente d regulation s sinc eP. 5

Madelein e Stru

mDRAF T Octobe r 23 , 199 5 Pag e 2 th e SCAQM

D rul e wa s issue d (se e industr y descriptio n memorandum 1 ) , som e o f whic h provid e simila

r option s o r

restriction s o n th e monome r content o f th e resi n on a

n "a s applied " (i.e . afte

r filler an d additiona

l styren e hav e been added ) basis . Whil e th e grea t majorit y o f application s us e larg e quantitie s o f inorgani c soli d fille

r material , eliminatin g th e nee d fo r thes e lowe

r monome r conten t resins , lo w styren e (les s tha

n 3 5 percent

o r less ) resin s are availabl e an

d i n us e i n Californi aand i

n man y other areas . Thes e resin s typically hav e ahighe

r viscosity , s o i t

ma y b e mor e difficul t fo r th e resi n to we

t asurfac e and saturat e glas s fiber. 2 Limite d studie s provid e indication s tha t low-styren e resin s can reduc e emission s when comparte d t o regula

r general-purpos e resins , however , they d o no t allo w adefinit

e o r precis e predictio n of

th e quantit

y of emissio n reductio n i n actua l productio n scenarios . A demonstratio n projec t

entitle d Reducin g Styren e Emission s in Fibe r Reinforce d Plastic s Operations 6 conducte d b y th e MinnesotaTechnica l Assistanc e Progra

mfound tha

t styren e emission s fro

mlow-styren e resin s wer

e reduce d b y 2 5 t o 4 5 percen t compare d t o aconven * tiona l Ortho-base d genera

l purpos e resin . However

^ th e emission s measure d fro mth e simulate d productio n trial s wer e no t atypica l open moldin g process , an d th e emission s quantifies d ma

y not directl y appl y t o actua

l operations . A Finnis h stud y reporte d tha

t low

styren e resin s reduce d tota l styren e evaporatio n b y 3 0 t o 6 0 percent compare d to astandar

d resin . I n thi s test , ahan d la y u p operatio n wa s conducte d under alaborator

y hood . (REFER ? ENCE : AJ . Saamamen

> R.X . Mlemela , T.K . Blotnquist , an d E.M . Kikander , Emissio n o f Stryin g Durin g th e Han d Lay-U p Moldin g o f

Reinforce d Polyester , Applie d Occupatio n Environmenta

l Hygiene , 6(9):790-793 , Septembe r 1991. ) I n astud y performe d b y amajo

r resi n supplier , o

f seve n resin s o f differen t type s rangin g i n styren e conten

t fro m32. 5 to 4 8 percent ; wer e compared . Th e tw o lo

w styren e (32. 5 an d 3 4 percent) viny l ester

resin s los t

a n averag e o

f 2 0 to 4 0 percent

les s styren e a s emission s tha

n th e standar

d resins . Th e proces s teste d wa s alaborator y simulatio n o

f ahan d layu p proces s i

n whic h atongu e blade , bu

t n o roller a s would normally b e use

d i n produc

-P. 6

Madelein e Stru

mDRAF T Octobe r 23 , 199 5 Pag e 3 tion , wa s used to sprea

d th e resi n an d we

t out th e glass. 3 Therefore , i t

ma y no t represen t emission s an

d emissio n reduction s expecte d in a n actu<a l han d la y u p productio n process .

The EPA' s Office of

Researc h and Developmen t (ORD ) carrie d ou t

adetaile d tes t progra mi n mid-199 5 to evaluat

e th e emissio n reductio n potentia l o f severa l pollutio n preventio n measures. 4 Ge

l coat s containin g 25. 4 an

d 38. 7 percen t

styren e an

d a n MEK P catalys t wer e spraye d ont

o amal e FR P mold usin g thre e type s o f spra y guns . I n nine run s wit h each-resi n gelcoat , th e low-VO C ge l coa t reduce d tota

l emission s whe

n compared to th e regula r ge l coat . Whe

n measure d in unit s o

f gram s emitte d pe r

squar e mete r o f mol d surface , th e reductio n wa s 2 8 percen t (17 0 t o 12

2 g/m 2 ) . (The SCAQM

D Rul e 116

2 stati c emissio n test , which determine s only curin g emissions , indicate s a3 7 percent reduction. ) I

n term s o f percentag e o

f availabl e styren e (AS ) emitted , th e reductio n wa s onl y 3. 2 percent (56. 0 to 54. 2 percent

AS) . Thi s indicate s tha

t th e emission rat e ha

d littl e dependenc e on monome r content , and tha

t styren e conten

t wa s th e controllin g factor

i n th e weigh

t o f styren e evaporated . I n th e sam e tes t program , aserie s o

f five resin s includin g aDCPD-based-iow=styren e resi n tw o DCPD-base d resin s containin g 3$
. 3 an d 35. 3 percen t styren e catalyze d wit

h MEK P wer e applie d to amold wit

h th e sam e thre e spra

y guns . Emission s fro

mth e low

VOC (35. 3 percent

styrene ) resi n wer

e reduce d by 1 1 percent

(19 5 t o 17 3 g/m

2)-whe n eomparc d t

o controlle d resi n sprayup , o r 3 8 percent

(27 8 to 17 3 g/m 2 )-^en-compared-t o norma l resin sprayu

p (se e Sectio n 4.5.4 ) o

f alow-profil e DCPD-base d resi n (3873-percen t styrene) . [NOTE : WHE N CFA result s ar e available , the y will als o b e include d in thi s section ] 4.1. 2 Vapo r

Suppressant s I n th e lat e 1970's , ane

w generatio n o

f resins , sometime s terme d "lo w styreneP. 7

Madeleine Stru

mDRAF T Octobe r 23 , 199 5 Pag e 4 emission " (LSE) resins , wa s introduced . Thes e LS E resin s contai n asmall quantit y o f wa x o r paraffin , o r

som e other additive , tha

t i s dissolve d i

n th e resin . Typically , th e additiv e i s 1 t o 2 percent

o f th e resi n formulation . A s curin g begins , th e wa x migrate s to th e surfac e an d reduce s evaporativ e losse s of styren e an d othe r

volatiles . Thes e LS E resin s ar e presume d effectiv e a

t reducin g emission s onl

y in th e curin g o r

stati c stage . I

n th e precedin g dynami c phas e of

resi n applicatio n (sprayin g an d rollout) , th e barrie r paraffin filmi s continuously disrupte d and thu s essentially inactive . Bot h resin s an

d ge l coat s ca

n b e formulate d wit

h vapor-suppressin g additives . I n EPA' s 199 3 screenin g surve y ofth e industry , suppressant s wer e reporte d for

th e resin s use

d i n most moldin g processes , wit

h th e exceptio n o

f continuou s laminatio n and pultrusion . B y fa

r th e mos t prevalent usag e wa s in sprayu

p operation s (about

2 2 percent

o f al l sprayu p operations) . A

n earl y problemwit

h vapor-suppresse d resin s involve d thei r negativ e effects on interkimina r adhesio n (i.e. , laminat

e layer s would sho

w atendenc y to split o r separat e under stres s du e to th e presenc e o f th e suppressan

t additive) . Thes e problem s wer

e largel y overcom

e i n later generation s of

LS E resins . A stud

y reporte d i

n 1979 5 indicate d tha

t secondar y bondin g problem s ma

y occu r whe n th e resin , glass , o r

mold s are a t lo w temperature s (below 6 5 °F ) o r whe n th e initia

l laminat e ha s bee n allowe d to cure mor e tha n 1 6 hour s befor

e secondar

y laminatio n i s carrie d out . High concentration s o f suppressan t (beyond recommende d levels ) will als o caus e poo r bonding . Th e us e o f asuppresse d resin , eve

n though th e resi n itsel f

ma y b e mor e expensive , ca n result i n acos t saving s wit

h respec t to non-suppresse d resins . On e estimat e i s tha t a saving s o f a t leas t $10 0 pe r 40,00 0 l b o f suppresse d resin coul d b e realize d du e t o about 1,40 0 fewe r pound s of

styren e los t

fro mth e resin. 5 Additiona

l cos t saving s ma

y b e realize d through areductio n i

n ai r ventilatio n cost s necessar

y t o mee t OSH A workplac e styren e concentratio n limits. 6 A recen t developmen

t i n LS E ge l coat s i s age l coa t wit h a2 5 percent

styrene conten

t a s well a s avapor-suppressin g wa x additive . Whil e no

t ye t full y commercially available ,P. 8

Madelein e Stru

mDRAF T Octobe r 23 , 199 5 Pag e 5 thi s produc t

i s undergoin g laborator

y trial s an d testin g a t anumbe r o f facilities , an

d i s being used a t one o r tw o facilitie s on a

n ongoin g basis . Th e propertie s o f thi s produc t

ar e claimed to b e comparable , and i n som e case s superior , to thos e o f currentl y availabl e ge l coats. 7, 8 Th e emissio n reductio n achieve d b y th e us e o f suppressant s i s afunction o f th e typ e an d amoun

t ol * supressen

t an d tb e typ e o f

resi n use d wit

h th e suppressant . Thi s furthe r complicate s ou r

abilit y to compute o r

predic t th e qu^tit y o f

emissio n reductio n afforde d by vapo r suppresse d resin s i n actua l productio n scenarios . Th e followin g describe s variou s test s which hav e been performe d t o stud y th e reductio n o f

emission s achieve d b

y th e us e o

f vapo r suppresse d resins . I n th e stud y referre d to previousl y in thi s section 5 , stati c emissio n test s wer e performe d to examin e th e effectivenes s o f suppressant s on curin g emissions . Unfilled , catalyze d resi n wa s weighe d int o a1-gallo

n ca n li d and weigh

t reading s wer

e taken ever

y 5 minute s over

a30-minut

e period . Styren e losse s were foun d t o b e a s muc

h a s 5 0 percent lowe r fo r resin s containin g asuppressant . A stondar d catalyze d sprayu

p resi n applie d t

o a glas s ma t wa s als o tested , an

d th e suppressan

t wa s foun d to reduc e th e weigh

t los s b y 5 7 t o 8 0 percent . A

n isophthalic , filamen

t windin g resi n subjected to th e sam e "ca n lid " tes t showe d a7 6 to 8 1 percent

reductio n i

n styren e monome

r los s whe n asuppressan

t wa s used . Finally , i n a n evaluatio n o

f fille d resin s containin g hig h level s o f th e fire retardant

alumin a trihydrate (suc

h a s use d in th e tub/shower industry) , styren e losse s wer e reduce d b

y abou t 7 0 percent through th e us e o

f asuppresse d resin . I n addition , i t wa s foun d tha t th e suppressan t acte d a s awettin g agent , providin g faste r glas s wetout

and necessitatin g les s rollout . I n anothe

r tes t program , styrene-emission s wer e compare d between-two-conventiona l (38. 0 and 33. 1 percent

styren e content) . Th e tw o conventiona l resins-were-catalyzed-with rron^TiT4)7-^oth-th eP. 9

Madelein e Stru

mDRAF T Octobe r 23 , 199 5 Pag e 6 stati c "ca n lid " tes t an d aproces s tha

t simulate d asprayu

p an d cure operatio n were-carrie d ou t o n th e samples . I n th e stati c tests , th e emission s fro mth e LS E resin s wer

e 2 4 to 3 0 percen t les s tha n th e emission s fro

mth e conventiona

l resins. Overal l emission s i n th e sprayup/cur

c proces s range d fro

m2 5 to 3 6 percent

les s whe n usin g th e LS E resinsr 6 [Thi s emission study teste d LO W styren e resins , no tvapo r suppressed resins . Itdoes no t belong in th e vapo r suppresse d section . Thi s sectio n can , however , b e moved to th e previous sectio n regardin g lowe r styren e conten tresins. ] I n th e sam e EP A testin g mentione d abov e in Section 4.1.1 , vapor suppressant s (includin g th e additio n o

f extrawa x additive ) wer

e foun d to reduc e styrene emission s durin g curin g a s compare d t o non-suppresse d resins. 4 On e orth o styrene-suppresse d resi n catalyze d wit h MEK P and th e sam

e suppresse d resi n wit

h a n additiona

l 0. 1 percen

t wa x wer e compare d wit

h th e DCPD-base d low-profil e resin . Th e suppresse d resin reduce d emission s b y 5 5 3 5 percen t

(27 8 19 5 t

o 126 g/m 2 ) , o r

by 6 1 |§fpercen t

h i unit s o f percent availabl e styrene (27r i 17. 5 to 10. 6 percent AS) . Tota

l emission s fro

mth e resin containin g addi

tiona l wa x (suppressant

) wer e not significantl

y differen t fro mth e "normal " suppresse d resin . However , prereleas e of

th e par t fro mth e mold wa s observe d fo r part s mad

e fro mth e resin wit h additiona

l wax . 4.1. 3 Dynami c Phas e Suppressio n > A s discusse d above , th e vapo r suppressin g additive s used i n LS E resin s arei!||||||mi | effectiv e onl

y i n th e curin g o r

stati c stage . A ne

w lin e o f resins , incorporatin g aproprietar y concept terme d "intrinsi c styrene emissio n reductio n technology " (INSERT) , ha s bee n develope d which th e manufacture r claim s als o exhibi t

reduce d styren e evaporatio n an d los s i n th e dynami c phase s of

th e process . Thes e resin s contain onl y 2 5 percent

styren e b y weight . Th e first

of th e ne w resin s include apre-accelerate d genera l purpos e laminatin g resin and a

n LS E versio n containin g avapor-suppressin g additive . Th e manufacture r claim s tha t mechanica

l propertie s o

f thes e resin s ar e comparabl e t o conventiona

l genera l purpos e resins , and th e volume shrinkag e i s 1. 5 to 2 percent les s tha n tha t o f conventiona

l resins . I nP.1 0

Madelein e Stru

mDRAF T Octobe r 23 , 199 5 Pag e 7 test s a t th e manufacturer' s facility , th e INSER T resin emitte d 5 0 percent

les s styren e tha

n bot h th e standar

d and th e LS E (conventional ) resi n i n th e dynami c phas e o f th e sprayu

p 9 1 0 process . ' 4.1. 4 Catalyst/Initiato r

Substitutio n Testin g ha s indicate d tha

t substitutio n of

benzoy l peroxid e (BPO ) fo r th e catalys t

(o r initiator) methy l ethy l keton e peroxid e (MEKP ) ma y dramatically reduc e th e emission s tha t occur durin g th e curin g process . Par t o f thi s effec t ha s bee n attribute d to areductio n i n ge l time an d alower pea k exother m(temperature ) whil e curin g a t roo mtemperature . I

n on e test , th e sam

e amoun t o f materia l wa s spraye d onto tw o molds , using th e sam e spra y boot h and th e sam

e cpncentratio n o

f initiator . Durin g th e curin g process , th e styren e emitte d fro m th e laminat

e containin g BP O wa s determine d to b e two-third s les s tha n th e styren e emitte d fro mth e laminat

e containin g MEK

P a s acatalyst . Th e mechanis mthough t to b e responsibl e for thi s differenc e concern s th e ge l time s o f th e tw o resi n formulations , about 1 hour fo r th e BP O catalyze d resi n and about 4 8 hour s fo

r th e MEK P catalyze d resin. 1 1 I

n anothe r study 6 , BPO-catalyze d resin outperforme d th e abilit y o f MEKP-catalyze d resin to reduce emission s i n bot h stati c cure an

d sprayup/cur

e simulate d productio n trials . I n th e stati c cure ("ca

n lid" ) tests , emission s fro

mth e BPO resi n (43. 9 percent styrene ) wer

e 50. 9 g/m

2 , versu s 69. 6 g/m

2 fo r th e MEK P resin (46. 0 percent

styrene) , o r

2 7 percent

lower . I n th e sprayup/cur

e trials , BPO resi n showe

d 4 9 percent

les s emission s i

n th e spra y phas e an

d 3 5 percent les s emission s i

n th e curin g phas e a s compare d t o th e MEK P resin . I n EPA' s recen

t evaluatio n tes t

program , emission s wer

e no t significantl

y differen t betwee n resin s catalyze d wit

h BPO versu s MEKP. 4 One DCPD-base d resi n catalyze d wit h BPO wa s use d i

n th e tes t serie s t o verif

y whethe r th e us e o f BP O i n plac e o f MEK P would b e a n effectiv e emissio n reductio n measure . Tw o versions , anea t resi n wit h 2. 1 percent BPO catalys t

(slow gel time ) an

d afiim e silic athickene d resin wit h 3. 1 percen

t BP O catalys t (fast ge l time) , wer

e tested . Th e result s showed tha t fo r bot h BP O resin s th e emission s wer e highe r tha n fo r th e low-profil e resi n catalyze d wit h MEKP . Th e nea

t BPO resin showe

d a n /P.1 1

Madelein e Stru

mDRAF T Octobe r 23 , 199 5 Pag e 8 increas e o f 6 9 percent

(19 5 to 33 0 g/m 2 ) , o r

5 0 percent

i n term s o f percent A S (17. 5 t o 26. 2 percen t AS) . Th e modified BPO resi n showed increase s o f 1 5 percent

(19 5 to 22 5 g/m

2 ) an d 2 2 percent

(17. 5 to 21. 3 percent

AS) . Thes e result s contradic t th e earlie r

testin g results . I t shoul d b e note d that

styren e content s ofth e BP O resin s were 46 % a s compare d t o 38 % fo r th e DCP D "baseline " resin . Additiona l informatio n documentin g th e mechanism s affectin g emission s whe

n usin g thes e tw o catalyst s need to b e collecte d befor e thei r effects ca n b e positivel y determined . 4.1. 5 Alternativ e Monomer s and Resin Formulation s A numbe r o f volatil e monome

r component s ca

n b e use d a s across-linkin g agent/solvent

i n th e resins , th e mos t

common o

f thes e bein g styrene , methy l methacrylate , an d viny l toluene . O

f these , styren e i s by fa

r th e mos t prevalent . Bot

h styren e an

d methy l methacrylat

e occu r on th e Clea

n Ai r Act' s lis t o f hazardou s ai r

pollutant s (HAP) . Fo r

most purposes , styren e i s typically th e monome r o f choic e and i s not

likely to b e replace d t

o an y grea t extent in th e foreseeabl e future . Epox y resi n system s ar e availabl e a s direc t replacement s fo

r polyester o r viny l este r resin s use d i

n sprayu p and han d layu p processes . Som

e manufacturer s claimsevera l advantage s fo

r epoxies , includin g resistanc e to blistering , superio r fatigu e and impact resistanc e and fractur

e toughness , an

d outstandin g adhesio n i

n secondar

y bondin g applica

tions . Thes e resins als o hav e alonge r shel f lif e an d lo w flammability. Mos t

significantly , epoxie s contai n littl e o r

no volatil e organi c compound s o r HAP . Therefore , thei r

contribu

tio n to th e HA P emission s fro macomposite s facilit

y i s ofte n negligible . Epox

y resin system s ar e mor

e expensiv e tha

t styrenate d polyester

o r viny l ester

resins o n aper-poun d basis , bu t th e advantage s cite d abov e ma y ofte n compensat

e fo r thi s disadvantage. 1 2 Light-cure d o r

photo-cure d resin i s anothe r materia l tha t ha s ha d som e applicatio n i

n th e composite s industry . Th e EPA' s 199 3 screenin g surve y identified on e facilit

y manufac

turin g chemica

l resistan t laminate s usin g photo-cure d resin s i n acontinuou s laminatio n process . I n processe s usin g photo-cure d resins , a n additiv e wit

h sensitivit

y to ultraviole t CP.1 2 i

Madelein e Stru

mDRAF T Octobe r 23 , 199 5 Pag e 9 (UV ) ligh t i s mixe d int

o astandar

d resin , th e resin i s applied , th e produc t i s exposed to ligh

t wit h aspecifi c U

V wavelength , and th e produc t cure s usually within 1 0 seconds . Thi s curin g proces s involve s th e decompositio n o f th e photoinitiato r

b y exposur e to aparticula

r wavelengt h of light . Onc e expose d t o U V lightin g o r

direc t sunlight , th e decompositio n produce s free radical s whic h trigge r th e polymerizatio n reactio n o f th e resin . Th e curin g agen t o r initiato r ca n b e used in either

polyester o r viny l ester

resins. Th e composit

e ca n usually b e remove d fro

mth e mol d within 1 0 minutes . Withi n 1 0 second s o f th e initia l ligh t application , th e styren e i s "locked " inside th e part and emission s cease . Thes e photo-curin g additive s hav e no effec

t i n reducin g emission s durin g sprayin g o r other applicatio n methods , bu t onl y durin g curing . Photo-cure d resins hav e severa l advantages : the

y requir e no mixing wit

h catalyst s o r promoters ; there ar e n o limit s on processin g time , s o layu p ca n procee d i

n stages ; th e resin exhibit s fas t

gellin g an

d shor t curin g times . Also , unuse d resi n tha t i s not expose d t o U V radiatio n ca

n b e returned to storage . Sinc e resi n doe s no t need to b e mixed wit

h acatalyst , i t ca n b e applie d directl y wit

h aflow coate

r o r rolle r (se e Sectio n 4.2.2 ) without amixin g and meterin g system . Finally , sinc e cur e begin s a t th e surfac e and move s inward , evapora tio n o f styren e fro

mth e surfac e durin g cure i s reduced. 1 3 A relatively ne

w resin formulatio n (Wate r Emulsified Technology , o r W.E.T . resin ) consist s o f awate r emulsio n tha

t contain s 4 0 percent

les s styren e tha

n standar d polyester resins. 1 4 Thi s resi n i s produce d by addin g proprietar y agent s to th e resin and wate r components , an

d then blendin g the

mtogether . Th e wate

r emerge s fro

mth e resin durin g th e curin g process , an

d ahig h densit y cellula r structure i s produced . N o pos t curin g i s required . Secondar

y bondin g ma

y b e enhance d du e t o th e propertie s o f th e agent s tha

t ar e adde d t o emulsif

y th e resin . Whil e no forma l emissio n test s hav e bee

n performed , th e develope r o f th e resi n constructe d afishing boa t usin g th e W.E.T . resin an d claime d tha

t worker s wer

e abl e to continu e to wor

k i n aclose d buildin g without specia l ventilatio n o r respirator y protection , bu

t needed to frequentl

y leav e th e buildin g whe

n th e sam e proces sP.1 3

Madelein e Stru

mDRAF T Octobe r 23 , 199 5 Pag e 1 0 wa s performe d wit

h astandar

d resin system . Further , th e qualit y o f th e finishe d produc t mad e fro mW.E.T . resin wa s claime d t o b e excellent . Th e wate r emulsifie d resi n ca

n b e use d wit

h eithe r MEK P o r BPO catalyst s an

d standar d spra y equipment . I n EPA' s 199 3 screenin g survey , on e facilit y wa s using awater

= base d resi n fo

r par t o f it s production , and expresse d satisfactio n wit h th e results. Attha t facility , hea

t wa s bem g applie d t o th e part s to cure th e resrn. Addition d testin g b y means-of forma l tes t method s wil l b e necessar

y befor e th e merit s o

f water-base d resi n system s cairb e properl y evaluated . [Ohi o confirme d thatthi s facilit y wa s usin g a n epox y water-based system , no

ta polyeste r waterbased system ] 4. 2 EQUIPMEN

T CHANGE S 4.2. 1 Improve d Sprayin g Equipmen t Th e thre e principa

l type s o f spra y gun s use d i

n th e industr

y ar e airless , air-assiste d airless , and hig

h volum e low pressure (HVLP) guns . Airless gun s rely o n high fluid pressure s i

n th e rang e o

f 1,00 0 t o 3,00 0 ps i t o delive

r resi n to th e mold i

n resi n applicatio n and resin/chop sprayu

p operations . Thes e high pressures , whil e necessar y fo r atomizatio n and spra y patter n development , ma

y contribut

e to excessiv e fogging , overspray , an d bounce-back

durin g resi n application . Th e consequenc e i s tha t exces s us e o

f resin an d subsequen t evaporatio n and los s of

th e volatil e monome

r componen

t prio r t o curin g contribute s to emissions , exces s waste , and adde d materia l expense . ||||B||||l||i||iii i industr y believ e tha

t airles s gun s ar e bein g phase d ou t i n thi s industry , an d thei r

us e i s not common . Lik e airles s guns , air-assisted airless guns us e fluid pressure to atomiz e resins , bu t th e pressure s ar e considerably lowe r (40 0 to 1,00

0 psi) . Fo r

thi s reason , pressurize d ai r a t 3 to 3 0 ps i i s introduce d int

o th e resi n spra

y patter n a s i t exit s th e pressure nozzle . Whil e thes e gun s canno t

matc h th e hig h volume s o

f materia l transfe r o f conventiona

l ai r spra y an d airles s guns , ^^t^S^BER|the y appea r t o reduce th e excessiv e resin us e tha t accompanie s us e o f thes e other

guns . Thi s make s fo

r acleane r wor k environmen

t and , conse -P. M

Madelein e Stru

mDRAF T Octobe r 23 , 199 5 Pag e 1 1 quently , les s overspra

y and les s monome

r emissions . Thi s sprayin g equipmen t ca n b e adapte d to existin g resi n deliver y system s a

t arelatively lo

w cost . A mor e recen t developmen

t i s th e introductio n o

f HVLPspra

y equipmen

t simila r to tha t in us e in man

y paintin g operations . Thes e gun s utiliz e low pressure ai r spra y (1 0 ps i o r less ) delivere d t

o th e gu n a t hig h volume s (1 0 t o 2 0 cfm) . Materia l (hydraulic ) pressure range s between 20 0 and 2,00 0 psi . Onc e th e ge l coa t o r resi n leave s th e orifice , th e lo w pressure ai r

complete s th e atomizatio n and encapsulate s th e resi n fa n on it s wa

y t o th e mol

d surface . Thi s create s asoft , lo w velocit y spra y which reduce s th e leve l o f overspray . Transfe r efficiencie s i

n th e rang e of

6 5 percent

(versu s abou

t 4 0 percent

fo r conventiona

l ai r spra y guns ) hav e bee

n reporte d by on e manufacture r fo r HVLP equipment . I n on e compari

so n o f airles s an d HVLP spra

y a t aboa t buildin g facility , th e HVL P spra y equipmen

t reduce d th e overspra

y by a n estimate d 2 5 percent. 1 5 Th e EPA' s 199 3 screenin g surve y indicate d tha

t 1 1 ge l coatin g operation s (7. 2 percent) an d 7 sprayu p operation s (4. 4 percent

) wer e usin g HVLP . N o datawer e provide d i

n th e surve

y o n th e us e o

f airles s o r air-assiste d airles s equipment . I n EPA' s recen

t tes t program , i

n which significan

t effort s wer

e take n to kee p operato r spra y technique s th e same , thre e gu n type s wer

e tested : air-assiste d airless/external mi

x (AAA) , HVLP/external mix , and HVLP/interna l mix. 4 I n a n experi

men t in which tw o ge l coa

t formulation s wer

e spra y applied , th e AA

A gu n wa s considere d th e baselin e cas e an

d wa s compare d to th e HVLP spra y guns . Th e effects of

interna l an d externa l catalys t mixin g wer

e evaluate d fo

r th e HVL P spra

y guns . Th e measure d tota l emission s for

th e regula

r ge l coa t wer e 373 , 387 , and 40 0 gram s fo r th e AAA , HVLP/internal , an

d HVLP/externa

l spra y guns , respectively. Fo r

th e low-VO C gel coat , emission s wer

e 272 , 278 , an

d 28 4 gram s fo

r th e thre e guns . Th e conclusio n fro mth e 1 8 tes t run s wa s tha

t there wa s no differenc e i

n emission s whe

n usin g thes e particula

r gu n types ; i.e. , th e transfe

r efficiency o

f eac h o f th e gun s wa s similar . Additiona l information will hav e to b e collecte d to properl y evaluat e th e efficiencie s o

f th e availabl e spra

y guns .P.1 5

Madeleine Stru

mDRAF T Octobe r 23 , 199 5 Pag e 1 2 Transfe

r efficiency (th e amoun

t o f spraye d materia

l actually accumulatin g o

n th e mol d expresse d a s apercentag e of th e tota l amoun t o f materia l leavin g th e spra

y gun) i s a function not

onl y o f th e specifi c applicatio n equipmen t bu t als o of th e mol d shap e an d size , ai r flo w throug h th e wor

k area , and th e techniqu e o

f th e operator , whic h i s -(probably th e larges t impact)-(thi s i s discusse d i n more detai l i n sectio n 4.5.4) . 4.2. 2 Substitutio n fo

r Spra y Equipment

7, 8 Pressure-fed

roller dispensin g o

f resi n i s bein g fairl

y widel y use d a s a n alternativ e to spra y application . Lik

e sprayin g systems , resi n rolle r dispense r unit s utiliz e alow-pressur e fluid pumpin g syste

mt o dra w resi n fro

mdrum s o r

bul k distributio n lines . Thi s pumping syste mals o include s aseparate , adjustabl e catalys t pump . Deliver

y rate s fo r catalyze d resin s ma y b e a s hig

h a s 2 0 pound s pe r

minute . A s th e operato r

roll s out th e reinforcing material s in th e mold , th e flo w of resi n ca n b e applie d an

d controlle d a s needed through a trigger mechanism . Resin roller

dispenser s ca

n transfe r catalyze d resin s to th e molding surfac e whil e totally eliminatin g th e dynami c materia l losse s inheren

t i n th e sprayin g process . Installatio n o f thi s equipmen

t doe s no t require majo

r modification s t

o th e productio n facilit

y o r th e toolin g alread

y i n place . Th e protectiv e clothin g and respirator y protectio n needed i

n spraying i s als o eliminated . Resin roller s are availabl e through mos t companie s tha

t manufactur

e spra y equipment . Manufacturer s claimtha t aresi n rolle r

will sav e alaminator 5 to 1 0 percent

i n resin usag e compare d to spra y application . Figur e 4- 1 show s aschema

ti c diagra mo f aresin rolle r

dispenser. 1 6 Anothe r technolog y bein g use d to reduc e th e styren e emission s associate d wit h spraying i s th e flow coater. Thi s syste mmake s us e o

f aspecia l gu n (eithe r resin/chopper o r straigh t resin ) tha t dispense s resi n i

n narrow , nonatomize d streams , rather tha n i n amis t a s fro mregula r spra y guns . I n EPA' s recen

t evaluatio n tes t

program , emission s fro

mth e us e o

f pressure-fe d resin roller s an

d flo w coater s wer

e compare d t

o emission s fro

msprayin g wit

h AA A guns .P.1 6

Madelein e Stru

mDRAF T Octobe r 23 , 199 5 Pag e 1 3 Th e nonsprayin g equipmen t reduce d tota

l emission s b

y 3 1 t o 3 3 percent

whe n compared to controlled

sprayin g (i.e. , extr aeffor

t wa s expende d to minimiz e overspray) , an d b y 5 2 to 5 3 percen t whe n compare d to normal

(ie . t effor t wa s mad e t o simulate productio n lin e |||||p|||resi n spra

y application . Th e differenc e in total emission s between th e flow coate r and th e pressure-fe d roller

wa s no t statistically significant. 4 I n EPA' s 199 3 screenin g survey , on e facilit y reporte d tha

t the y were applyin g gel coa t usin g brushe s (bathtub s and spas ) and thre e reporte d th e us e o f roller s (swimming pools , bu s bodies , Md chemica l storag e tanks) . 4.2. 3 Fabri c Impregnator s Reinforcing fabric s pre-saturate d wit h resin (an

d the n coole d afte

r reachin g astat

e o f partial curing) , know

n a s "prepreg, " ar e use d in certai n laminatio n operation s becaus e ofth e advantage s the

y offe r i n produc t qualit y control , productio n efficiency , and cos t effective

ness . A primar

y us e fo r prepreg s i s i

n th e advance d composite s market , suc h a s th e aerospace/defens e industry . Fabri c impregnato r equipmen t i s availabl e tha

t provide s som

e of th e advantage s offere

d by prepreg s whil e usin g lowe r cos t polyester resin s an d glas s reinforcements . Impregnator s ca n b e installe d s o a s t o fee

d resi n saturate d reinforcin g material s directly t

o th e moldin g operation . Wove n glas s roving s ar e impregnate d a s the y pas s throug h areservoir

syste mcontainin g catalyze d resin . Figur e 4- 2 show s a

/ < ^Madeleine Stru mDRAF T Octobe r 23 , 199 5 Pag e 1 4 P.1 7P.1 8

Madelein e Stru

mDRAF T Octobe r 23 , 199 5 Pag e 1 5 Figur e 4-1 . Pressure-fe d resin roller dispenser. 1 6Madeleine Stru mDRAF T Octobe r 23 , 199 5 Pag e 1 6

Figur e 4-2 . Resin/fabri c impregnator system. 1 7 P.1 9



# rzP.2 0

Madeleine Stru

mDRAF T Octobe r 23 , 199 5 Pag e 1 7 schemati c o

f aresin/fabri c impregnator system. 1 7 Fabri c impregnatio n clearly ha s emissio n reductio n advantage s whe n compare d to spra y operation s by eliminatin g atomizatio n an d waste d resin . Fo r

man y fabricators , installatio n o

f impregnato r

system s ma

y require extensiv e modification i n th e plant

layou t an d productio n techniques . The potentia l for saving s i s greates t

wher e operation s demand th e productio n o

f larg e volume s o r

resi n saturate d rol l stock. 1 7 4. 3 OPERATIONA

L PARAMETE

R CHANGE S 4.3. 1 Covere d Resin Bath s fo r Pultrusio n Operation s Coverin g o r

partiall y coverin g th e resi n bat h o r reducin g th e siz e o

f th e bat h i n a n attempt t o reduc e evaporatio n o

f monome r fro mth e resi n ha s bee

n trie d t o alimite d exten

t a t pultrusio n facilities . Test s a t facilitie s wit

h covere d bath s indicat

e tha t thi s measur

e ma y hav e a n emissio n reductio n impact , but thi s impac t

ha s not bee n quantified . [Result s fro

m recen t Pultrusio n Industr

y Counci l testin g o

f alaborator

y pultrusio n proces s a

t Reichhol d Chemical s wil l b e adde d whe n available. ] 4.3. 2 Ai r Flo w Effects Th e Pultrusio n Industr

y Council , a

n activit y of th e Societ y o f th e Plastic s Industr

y Composite s Institute , conducte d a n initia l (Phas e I ) serie s o

f experiment s to characteriz e th e effec t o f ke y operatin g variable s o n styren e emission s fro mth e pultrusio n process. 1 8 Among th e variable s studied , ai r

flow tiirough th e tes t

chamber (an d pas t th e ope n resi n bath ) ha

d b y fa r th e larges t

effec t on emissions . On

e conclusio n fro

mthi s stud

y i s tha t an y ope n resin bat h surface s shoul d b e shielde d fro mmoving ai r

stream s i n order to reduc e emissions . Thi s coul d include eithe r

rigi d o r curtain-typ e barrier s place d betwee n th e bat h and th e sourc e o f ai r flow. Th e magnitude o f

th e effec t o f ai r flo w o n emission s wa s On

e of th e mai n goal s of th e pultrusio n experimen

t conducte d Septembe

r 199 5 o n aful

l scal e pultrusio n inachin e set

u p t o manufactur

e ladde r rails . [ Result s wil l b e adde d when available. ] I n EPA' s recent

emission tes t

program , apilo t

experimen

t involvin g th e spra

y la y u p pjilll l wa s conducte d to evaluat e th e effects o n styren e emission s o f change s i n ai r flowP.2 1

Madelein e Stru

mDRAF T Octobe r 23 , 199 5 Pag e 1 8 velocit y i n th e spra y zone . A regular

isophthali c (iso ) gel coa

t catalyze d wit

h MEK P was spraye d usin g a

n AA A gu n i n alow (3 0 to 5 0 ft/min ) an d ahigh (9 0 to 12

0 ft/min) roo

mai r flo w velocit y representin g th e rang e o

f velocitie s foun

d i n a n ope n moldin g proces s are ao r i n aspra y booth . I

n thes e tests , th e effec

t of ai r velocit y o n emission s wa s foun

d t o b e statistically insignifican

t at th e ai r velocitie s tested. 4 4.3. 3 Temperatur

e Contro l Th e Phas e I pultrusio n stud y referre d t o abov e indicate d tha t alowere d resin mi

x temperatur

e coul d hav e th e effec

t of reducin g emissions , a

t leas t fo r th e pultrusio n process . Thi s parameter

chang e ha s no

t bee n studie d for

th e othe r fabricatio n processes . I t

i s expecte d tha

t asignifican

t coolin g of

th e resi n coul d hav e anegativ e impac t on process abilit y o r ge l time , and thu s coul d affect produc t propertie s o r

productio n rates. Anothe r approac h take

n by afe w pultrusio n facilitie s i s t o ai r conditio n (coo l an

d dehumidify ) th e entire plant productio n area . Beside s providin g amor e comfortabl e yearround workin g environmen t fo r employee s and coolin g th e resi n materials , thi s measur e should reduc e o r

eliminat e th e nee d for

high speed ventilatio n fan s on th e plant floor. Thi s i n tur n woul d lea

d to afurthe

r reductio n i

n emissions , a s discusse d abov e i n Sectio n 4.3.2 . 4.3. 4 Underwate

r Curin g Tw o facilitie s responding to EPA' s 199 3 screening surve y reporte d th e us e o

f underwate r curin g a s a

n emissio n reductio n measure . On e facility , amanufacture

r o f automotiv e parts , used thi s techniqu e fo r uncure d scra

p only . Th e other

facilit y manufac

ture d button s fro

mresi n cylinders . Thes e cylinder s are submerged i n wate r a t som e poin t i n th e curin g cycle . 4. 4 PROCES S CHANGES 4.4. 1 Vacuu

mBaggin g 4.4.1. 1 Traditiona

l ba g molding 1 9 Vacuu mba g molding i s atechnolog y tha t ha s bee n i n existenc e sinc e th e lat

e 1940's . I n thi s process , ge l coat , reinforcin g materials , and catalyze d resi n are applie d to a n ope n

- - c !P.2 2

Madelein e Stru

mDRAF T Octobe r 23 , 199 5 Pag e 1 9 mold , an d the n th e expose d are ai s covere d by specia l layer s o f plasti c shee

t whic h ar e sealed to th e edge s o

f th e mold . Befor

e th e resin begin s to cure , avacuu mi s draw n through on e o r mor e strategically locate d port s in th e mol d o r th e plasti c cover . Vacuu

mmoldin g work s wit h flat, female , an

d mal e molded parts . Th e qualit y o f th e finished pjut s i s typically ver

y good . Produc t

wit h acontrolle d resin-to-fiber ratio ca n b e produce d t o b e virtuall y porosity-free . Small part s ca n b e made , and epoxies , phenolics , polyesters , an d viny l ester s ca

n b e used wit

h th e system . Vacuu mba g moldin g processe s ca

n b e se t up t o replace o r

supplemen

t man y conventiona

l (hand layu

p o r sprayup ) ope

n moldin g operations . Mold s ar e built fro mth e sam e material s and usin g th e sam e technique s a s require d fo r creatin g ope

n molds . Conventiona

l ge l coats , resins, and reinforcin g material s ca n b e used , an

d resi n deliver

y ca n b e accomplishe d without

atomization . Th e labo r

involve d i

n distributin g th e resi n and rollin g out ai r bubble s i s reduce d becaus e th e vacuu mcreate s adistributio n and compactio n o f th e laminate . T o th e exten

t tha t resi n applicatio n usin g spra y technique s ma

y b e reduce d o r

4 eliminated , monome

r emission s ca

n b e reduced . Vacuu

mba g moldin g doe s no t

reduc e emission s associate d wit

h th e applicatio n o f

th e resi n t o th e mold , o r

fro many othe r operatio n tha

t occur s befor

e th e ba g i s place d o n th e mold . I t i s presume d to eliminate th e emission s tha

t woul d occur

durin g th e curin g process . The emission s tha t occu r durin g curin g o n a n ope n mol d ca n b e dramatically reduce d du e to th e presenc e o f th e plasti c shee

t coverin g th e laminat

e durin g most

o f th e curin g cycle . Sinc e amor e precis e par

t ca n b e produced , th e trimof

f an d grindin g operation s ar e reduce d s o tha t les s dus t i s created . Vacuu mba g moldin g appear s to b e bes t suite d fo r intermediat

e volum e productio n o

f smal l to midsiz e components . Th e EPA' s 199 3 screenin g surve y indicate d tha

t vacuu mbaggin g (usuall y i n combinatio n wit

h sprayup ) i s bein g use d a

t abou t si x facilitie s to manufactur

e item s suc h a s traile r

panels , tub s and showers , missil e parts , and miscellaneou s other products .P.2 3

Madelein e Stru

mDRAF T Octobe r 23 , 199 5 Pag e 2 0 AAA.2 Infusio n moldin g Infusion share s man

y o f th e characteristic s o

f vacuu mba g moldin g and resi n transfe r moldin g (se e Section s 4.4.1. 1 an d 4.4.2) . Figur e 4- 3 show s acompariso n o f th e vacuu m baggin g an

d infusion processes. 2 0 Lik e RT M (Sectio n 4.4.2) , infusion reduce s styren e emission s by wettin g ou

t and curin g th e laminat

e i n aclose d system . On e for mo f th e infusion process , known a s SCRIM P (Seema n Composit

e Resi n Infusion Moldin g Process) , provide s man y emissio n reductio n and produc t qualit y benefit s tha t it s developer s claimrival th e materia l and mechanica

l propertie s obtaine d fo

r advanced composite s (suc

h a s epox y part s mad

e i n th e aerospac e industr

y tha t ar e cure d i

n aP.2 4

Madelein e Stru

mDRAF T Octobe r 23 , 199 5 Pag e 2 1P.2 5

Madelein e Stru

mDRAF T Octobe r 23 , 199 5 Pag e 22 Figure 4-3 . Compariso n o f vacuu mbaggin g an

d infusion processe s 20P.2 6

Madelein e Stru

mDRAF T Octobe r 23 , 199 5 Pag e 2 3 temperature-controlle d autoclave). 7 Whil e th e developer s claimtha t almos t an y par t ca n b e manufacture d using SCRIM P technology , th e proces s i s especially suite d to large , comple x part s tha t hav e amediu

mproductio n rate, suc

h a s boa t hull s and decks . A s o

f Octobe r 1995 , th e proces s ha s been use d t o produc e th e followin g on aproductio n scale : windmill blades , larger

satellit e dishes , rai l cars , bridg e pilings , amusemen t rides, shuttl e bu s bodies , and assorte d part s fo

r th e military . I t

ha s als o bee

n use d t o mak e anumbe r o f other part s suc h a s swimmin

g pools . SCRIM P produce s composite s o f u p t o 70-7 5 percent

fiber conten t b y volume , and i s effectiv e wit h 50-10 0 oz . clot

h reinforcement s (u

p to 20 0 oz . cloth s ar e anticipate d in th e future). 8 A typica l productio n proces s utilizin g SCRIMP technolog y involve s th e following steps : 1 ) ge l coa

t i s applie d to th e mol d normall y usin g spra

y guns , 2 ) astabilizin g ski n coa t i s applie d t o th e mol d (als o usually spraye d on) , 3 ) th e outer fiberglass fabric s use

d a s th e outer ski n an d structura

l reinforcement s ar e place d agains t th e mold surfac e wit

h th e aid o f aresi n solubl e contac t

adhesive , 4 ) th e cor

e i s trimme d an

d place d i n th e mold , 5 ) th e balanc e o

f th e laminat

e i s place d in th e mol d includin g th e transvers e an d longitudina l stringers , 6 ) bagging material s ar e place d an d sealed ove

r th e mold , 7 ) avacuu

mo f approximately 3 0 inche s H g i s applie d an d maintained , 8 ) th e resi n i s draw n int o th e evacuate d laminat

e (approximately 4 5 minute s for a60-foo t boa t hull , an d 9 ) th e hull i s read y fo r demolding th e following mornin g o r a s soo n a s th e resi n cures . Step s 3 through 9 are considere d the SCRIMP process . Ste p 1 (an d sometime s ste

p 2 ) i s typically done a s a separat e proces s i

n conjunction wit

h sprayu p o r hand layu p moldin g processes . Advantage s claime d fo

r th e SCRIMP proces s are numerous . Compare d to prepre g (se e Sectio n 4.2.3) , SCRIMP eliminate s th e nee d fo r refrigerated storag e and th e processin g step s neede d t

o prepar e prepre g fo

r fabrication . Les s materia l i s needed to achiev e th e sam e results . Bette

r surfac e qualit

y eliminate s rewor

k t o correc t pinholin g an

d other surfac e faults . A SCRIMP sho

p i s acleaner

operatio n tha

n th e traditiona

l composite s shop , wit

h ver y littl e nee

d fo r cleanin g solvents .

Cs 'P.2 7

Madeleine Stru

mDRAF T Octobe r 23 , 199 5 Pag e 2 4 T o us e th e SCRIM P process , laminator s mus t pa y aone-time fe

e i n additio n to a royalt y base d on th e cos t

o f th e manufactur

e o f th e composit

e par t (labor , materials , manufacturing overhead) . Thes e cost s are fo r th e us e o f th e patent an d to pa y fo r trainin g coverin g som

e proprietar

y techniques . A s o

f 199 5 th e fe

e structur e i s a s follows : One-tim e fe e $25,00 0 $25,00 0 $100,00 0 Royalty 1

5 % 7 % 5 % Applicatio n

Boa t builder onl y Al l industria

l end-us e Al l industria

l end-us e Accordin g t o th e developers , thi s cos t i s offse t b y saving s i

n personne l healt

h and safet y equipment , plan t

maintenanc e an

d utilities , tool s and equipment , an d solven t costs . Fo r one licensee , ther e wa s aretur n on th e investmen

t i n les s tha n 1 year. 2 1 On e o f th e issue s facing SCRIMP (an d othe r reinforce d plasti c moldin g processes ) i s o f acosmeti c natur

e and i s loiow

n i n th e industr

y a s "prin t through. " Accordin g to th e developers , th e prin t

throug h profil e o

n SCRIMP part s i s somewha t differen t fro mtha t see n o n han d lai d parts ; however , i t

i s afunctio

n o f th e sam e phenomeno n (resin shrinkag e durin g th e cure cycle) . On e solutio n ha s bee

n t o paint thos e product s tha

t require ahig

h glos s finish . Anothe

r solutio n i s th e us e o

f aprin t throug h ski

n coa t (see ste p 2 i n th e proces s summar

y above) . SCRIMP continue s to underg o ne w developments . On

e recen t developmen

t i s th e us e o f reusabl e bags . Experiment s hav e show n tha t usin g th e correc t

silicon e materia

l wil l result i n over 25 0 cycle s wit

h th e reusabl e bags . Thes e bag s reduc e solid wast e an d als o (through asnap-on system

) ca n b e used t

o reduc e productio n time . Anothe r variatio n o

f th e infusio

n metho d i s calle d th e resi n infusio n recirculatio n 'I n case s wher

e productio n volume s are large , royalt y rate s hav e bee

n contractually reduced . 

## 7LP.2 8

Madeleine Stru

mDRAF T Octobe r 23 , 199 5 Pag e 25 metho d (RIRM) . Tiii s proces s utilize s asemi-rigi d cover tha t ca n b e reused , an

d provide s amiddl e groun d betwee

n vacuu mbaggin g an

d RTM . Dramati c emissio n reductio n benefit s are claime d fo r infusion processes . On

e compan y wa s abl e to reduc e it s styren e emission s to les s tha n 2 0 percent

o f previou s level s through adoptio n o

f thi s process. 8 I n order

to estimat e emission s fro

mth e SCRIMP process , on e operato r

installe d activate d carbo n filters i n th e lin e to th e vacuu mpump . Measurement s wer

e mad e by weighin g acarbo n filter (befor e and afte r th e SCRIMP) process ) tha

t wa s plumbe d paralle l t o th e 30-inch H g vacuu mlin e use d for

infusion . Result s indicate d tha

t onl y 0.009 1 percen t

o f th e availabl e styren e monome r wa s emitted. 2 1 4.4. 2 Othe

r close d moldin g fabricatio n processe s Close d mol

d technologie s ma

y offe r apractica l alternativ e to ope

n mol d processe s fo r reducin g curin g emission s and th e cost s associate d wit h ope n molding . Closed moldin g eliminate s requirement s for atomizatio n o

f resins and ma

y offe r anumbe r o f productio n advantage s ove

r other fabricatio n processes . Th e close d moldin g technologie s mos t frequentl y applie d t

o productio n o

f reinforce d plasti c composite s are resin transfe r moldin g and compressio n molding . Resin transfe

r moldin g (RTM ) i s considere d adirec t replacemen

t fo r traditiona l ope n mold han d layu p an d sprayu p laminatio n processes . Sinc e resi n i s transferre d directly int o a close d mol d containin g dr

y reinforcement, th e emission s associate d wit h exposur e of we t resin surface s t

o th e ai r are essentially eliminated . RT M application s ar e bes t

suite d fo r intermediat

e volum e productio n o

f smal l to midsiz e components . Thi s would include item s suc h a s restauran

t seats , doors , covers , recyclin g bins , automotiv e parts , an d bath/shower components . I n compariso n t o ope n molding , potentia

l saving s ar e greates t

whe n produc

tio n rate s ar e moderatel

y hig h and bot h side s o f th e par t mus t b e finished. 22 Compressio n molding , anothe r close d process , utilize s premanufactured , ready t o mol d materials , suc

h a s bul k moldin g compoun

d (BMC ) an

d shee t molding compoun

d (SMC) , rather

tha n liqui d resin s and reinforcements . Therefore , thi s proces s i s notP.2 9

Madelein e Stru

mDRAF T Octobe r 23 , 199 5 Pag e 2 6 considere d adirec t

replacemen

t fo r ope n molding . I n addition , th e cos t o f th e matche d meta l die s i s considerably highe r tha n for traditiona l ope n molds . However , i t

i s on e optio n i n case s wher

e th e soli d moldin g compound s ca n b e used an

d th e productio n volum

e i s hig h enoug h to mak e th e investmen

t in th e die s worthwhile . Injectio n molding (mos t

ofte n use d in conjunctio n wit

h thermoplastics ) i s anothe r close d proces s reporte d b y afe w composite s facilitie s on EPA' s 199 3 screenin g survey . Thermoset

product s mad

e b y thi s proces s include bowlin g balls , reflectors, an d circui t breakers . Th e benefit s o

f close d moldin g processe s in reducin g emission s ar e simila r t o thos e discusse d for

vacuu mbagging . However , reduction s fro mclose d moldin g ar e likely t o b e greater becaus e ba

g moldin g usually involve s applyin g th e resi n t o th e ope n mol d surfac e befor e th e ba g i s installe d on th e mold . 4.4. 3 Proces s Elimination/Substitutio n Th e sanitar

y produc t market (bathtubs , showers , tub/showers , spas/ho t tubs ) typically manufacture s it s product s usin g ope n moldin g processes . Ge

l coa t sprayin g followed b y resin/chop sprayu p i s th e typica

l process . However , certai n product s (espe

cially spas/ho t

tubs ) ar e als o produce d by substitutin g athermoforme d acryli c shee t for th e gel coa t layer . Thi s alternativ e produce s amor e expensiv e product , but

aver y smoot h an d durabl e finish i s produced . Through th e eliminatio n of th e sprayin g process , thi s proces s substitutio n eliminate s th e emission s associate d wit h ge l coating . Another proces s substitutio n involve s replacin g th e thermoset resin wit h athermo

plasti c material . Th e plastic s industr y a s awhol e use s fa

r mor e thermoplastic s tha

n thermosettin g resins . Thermoplastic s processin g offer s faste r curin g cycles , lowe

r cost s per poun d o r raw material , eas e o

f recycling , lowe

r labo r intensity , an

d lowe r VO C an d HA P emission s durin g processing . Ne w engineerin g grade s o

f thermoplastic s ca

n b e reinforce d wit h glas s o r other fibers , an d thes e material s ca

n riva l th e strengt

h o f man y o f th e stronges t thermosets . On

e compan y producin g fa

n blade s fo

r coolin g tower

fan s replace d th e han

d

or. 

## tP.3 0

Madelein e Stru

mDRAF T Octobe r 23 , 199 5 Pag e 2 7 layu p thermoset

blade s wit

h injection-molde d nylo n (thermoplastic ) reinforce d wit h lon g glas s fibers. Cost s fo

r th e nylo n versio n wer

e reported t o b e abou

t 3 0 percent

les s tha n for th e thermoset

product . Th e ne

w fan s showed goo d impac t resistance an

d rigidity, an

d wer e easie r t o balanc e du e to mor

e consisten

t weigh t uniformity. 2 3 4.4. 4 Resi n Injectio n in Pultrusio n Th e principal sourc e o

f monome r vapo r emission s i n pultrusio n operation s i s th e fiber wet-out area , includin g th e resin bat h and other

area s of th e machine i

n whic h wette d fibers ar e expose d to th e ope n air . I n additio n to coverin g th e resin bat h (se e Section 4.3.1) , anothe

r approac h bein g use d a

t som e facilitie s t o reduc e thes e emission s i s t o directly inject

resi n int o th e fiber preformin g statio n o r

directl y int

o th e forming di e itself

. I n resi n injection , th e resi n ca n b e store d in aclose d dru mand pumped u

p ont o th e produc

tio n lin e to directl y we

t th e fibers . I n th e preform injection process , resin i s pumpe d int o a prefor mbo x a s th e fiber

rovin g i s fe

d throug h th e box , s o tha

t th e resin saturate d fiber s onl y hav e to trave l th e distanc e between th e prefor mstag e an

d th e die . Prefor

minjection canno t b e used fo r certai n composite s wit

h complex shape s becaus e alarg e amoun t o f spac e i s necessar y to for mth e fibers. Direct

die injection involve s th e injection o f resin directl y int

o th e heate d forming die . Insufficien t wet-ou t of th e roving , and consequen t poo r produc t quality , i s on e of

th e chief problem s to b e overcome i n th e us e o

f resin injection fo

r pultrus

ion operations . Th e EPA' s 199 3 screenin g surve y showed tha

t resin injection i s bein g use d a t tw o facilitie s i n th e manufactur

e of beams , booms , channels , tubes , rods , and doo r panels . 4.4. 5 Substitutio n o

f Cleanin g Material s Th e liqui d cleaner s used t o clea n tools , spra

y guns , hands , an

d wor k surface s i n th e fabricatio n are aofte

n contain o r

consis t entirel y o f

VO C and/o r

HAP . Th e traditiona

l solven t i n th e industr

y ha s bee n acetone , which , unti l recently , was considere d b y EP A to b e aVO C (bu

t not aHAP) . However , on Jun e 16 , 199 5 (6 0 FR 31633) , EP A formall y remove d aceton e fro

mth e VO C lis t

an d classifie d i

t a s a n exemp t compound . I

n th e las t .yP.3 1

Madelein e Stru

mDRAF T Octobe r 23 , 199 5 Pag e 2 8 severa l year s anumbe

r o f non-VO C o r

low-VO C replacements for aceton e hav e bee

n introduce d and ar e i

n us e i n thi s industry . Th e statu s o f thes e substitute s tha

t contain lo w level s of VO C ma y hav e to b e reevaluate d wit h respec t to th e us e o

f acetone . Anothe r fairl y commo n cleanin g solven

t i s methylene chloride , which i s include d o n th e Clea n Ai r Act' s HAP list . Severa

l facilitie s reported on EPA' s screenin g surve y tha t the y hav e reduce d o r

eliminate d thei r

us e o f thi s chemical . 4.4. 6 Mixin g Operation s Close d mixing system s ar e availabl e for preparin g bul

k moldin g compound (BMC) , a paste-lik e mixtur e o f resins , fillers , pigments , catalysts , modifiers , and choppe d strand glas s fibers. A n exampl e i s th e Littlefor

d 60 0 lite r

BM C mixer . Thes e system s hav e cover s which remai n close d except whe n ingredient s ar e being added o r final BM C past e i s bein g removed . 4. 5 WOR

K PRACTICE S Wor k practice s are acategor

y o f pollutio n preventio n measure s consistin g o f improve d way s o

f handlin g o r

trackin g material s containin g pollutant s tha t lea d to a reductio n i

n emissions . Thes e practice s ar e carrie d ou t without making an

y significan

t change s t o existin g processes , s o the y are typically ver

y cost-effectiv e o r

ma y provid e acos t savings . Sinc e wor

k practice s depen d o n th e behavio r of th e employee s wh o ar e actually performin g th e fabricatio n operations , and who ma y no t normally b e associate d wit h pollutio n contro l activities , th e practice s ar e inseparabl y linke d wit

h employe e educatio n an

d training . I n orde r

fo r thes e measure s t o b e effective , employee s mus t b e traine d i

n th e prope r procedure s and the

n give n incentive s to carr

y the mou t on a n ongoin g basis . Th e following are suggeste d pollutio n preventio n wor k practice s base d o

n apolic y statemen t issue d by th e Composite s Fabricator s Association. 2 4 I t i s difficul t to associat

e a specifi c emissio n reductio n wit h eac h measure ; i

n practice , th e reduction s achieve d b y an y measur e woul d b e widel

y variabl e dependin g o

n th e specific natur

e o f th e practic e an

d th eP.3 2

Madeleine Stru

mDRAF T Octobe r 23 , 199 5 Pag e 2 9 diligenc e wit

h which i t wa s carrie d out . 4.5. 1 Materia

l Storag e and Handlin g Th e principal wor

k practic e involve s maintainin g covere d container s fo r al l resi n material s (resin s an

d ge l coats ) whil e they ar e bein g store d prio r to use . Drum s o

f materia l should b e opene d immediatel y befor e use , and reclose d a s soo

n a s practicable . Car

e should b e take n to avoi d spills . An

y spill s shoul d b e cleane d u p immediatel

y and th e soile d mops , rags, etc . place d i

n vapor-proo f

bag s o r can s unti l curin g i s complete , o r dispose d o

f properl y in th e cas e o

f uncatalyze d resins . 4.5. 2 Flui d Handlin g Equipmen t Man y operation s utiliz e resi n and ge l coa t transfe r system s t o pum

p resi n fro ma storag e vesse l o r

container to mixin g vessel s o r

directl y to th e fabricatio n process . Durin g al l phase s o

f flui d handling , cover s shoul d b e mauuaine d on vessel s a s muc h a s possibl e an

d spill s shoul d b e avoided . Fitting s an d pum p packing s should b e maintaine d s o a s to avoi d leaks . Resin line s and spra y gun s shoul d b e purge d int o approved , sealed container s afte r use . 4.5. 3 Mixin g Operation s Prio r t o application , nea

t (unfilled) resi n i s mixe d wit h promoters , catalysts , additives , and sometime s solid inorgani c fillers , ofte n in automate d (powered) mixing vessels . Cover s on thes e container s shoul d b e lef t full y i n plac e excep t

whe n addin g o r removing materials . A s discusse d abov e fo r othe r operations , spill s shoul d b e avoide d an d cleane d u p immediatel

y whe n the y do occur . 4.5. 4 Sprayin g Operation s Certai n wor

k practice s ca

n b e applie d t o reduc e emission s i n ge l coating , resin spra

y application , o r

resi n chop (laminate ) sprayu p operations . Spra

y applicatio n techniqu e i s a critica l factor i n increasin g transfe

r efficiency and thu s reducin g resin us e an d subsequen

t emissions . Generally , thos e procedure s tha t reduc e foggin

g an d overspray , an

d ensur e tha t th e maximu

mamoun t o f resi n i s deposite d on th e mold , will b e effectiv e i n minimizing

__>P.3 3

Madeleine Stru

mDRAF T Octobe r 23 , 199 5 Pag e 3 0 emissions . Thi s include s operatin g th e spra y gun a t th e lowes t

recommende d pressure , spraying clos e t

o and perpendicula

r t o th e mold , and maintainin g th e spra y fa n patter n within th e mol

d perimeter . I n EPA' s recent

evaluatio n tes t

program , apilo t

experimen

t wa s conducte d t

o evaluat e th e effec t o f operato r sprayin g techniqu e on styrene emission s fro mge l coa t spra y application . Thi s wa s don e by askin g th e operato r to spra y anorma l (uncontrolled ) patter

n an d acontrolle d pattern . Th e norm<a l techniqu e represente d n o specia l contro l o f th e overspra y pas t th e flange o

f th e mold , whil e controlle d spraying wa s carrie d out wit h a consciou s effor

t t o minimiz e overshootin g o f th e atomize d ge l coa

t beyond th e flange. Tota

l norma l sprayin g emission s average d 51 3 grams , whil e tota l controlle d sprayin g emission s average d 39 1 grams , representing a24 percent reductio n whe

n th e controlle d techniqu e wa s used. 4 One facilit

y reportin g i

n EPA' s 199 3 screenin g surve y establishe d astandar

d weigh t fo r eac h o f it s product s (bathtubs , showers , .an d tub/showers) , then generate d aweekl y compute r report showin g predicte d versu s actua l materia l usage . Th e productio n departmen t use d thi s report

a s atoo l t o wor

k wit h th e sprayer s to reduc e overspray , materia l waste , an

d emissions . 4.5. 5 Cleanu

p Operation s Cleanu p material s (rags , etc. ) saturate d wit h HAP-containin g cleanu

p solvent s should b e deposite d i

n vapor-proo f

bag s o r storag e cans . Container s of suc h solvent s should b e kep t closed , an

d spill s should b e avoide d and cleane d u p a s they ma

y occur . Th e minimu

m amoun t o f solven t neede d to perfor

majo b should b e used . Leftove r solven t should b e returned to storag e an d spen t solven t shoul d b e recycle d o r

dispose d o

f usin g ametho d approve d by th e loca

l agency .

~ i ZP.3 4

Madelein e Stru

mDRAF T Octobe r 23 , 199 5 Pag e 3 1 4. 6 REFERENCE S 1 . Memorandum . LaFlam , G . and Proctor , M. , Pacifi c Environmenta l Services , t

o Strum , M. , U.S . EPA . Septembe r 21 , 1995 . Descriptio n of

Plasti c Composite s Fabricatio n Industry . 2 . Hillis , Davi d R . and Davis , A . Darryl . Waste d Reductio n Strategie s fo r Fiberglas s Fabricators . Eas t

Carolin aUniversity . Greenville , NC . 1995 . p . 73 . 3 . Adkins , L.M. , Kitchen , K.E. , an d Landes , D.S. , Ashland Chemical , Inc . The Determinatio n o

f Styren e Emission s Durin g th e Hand Lay-u p an d Spray-u

p Processes . 48t

h Annua l Conference , Composite s Institute , Th e Societ y of th e Plasti c Industry . Februar

y 8-11 , 1993 . 4 . Kong , E.J. , Banner , M.A. , Wright , R.S. , and Clayton , A.C. , Researc h Triangl e Institute . Evaluatio n o

f Pollutio n Preventio n Technique s t o Reduc e Styren e Emis

sion s fro mOpe n Contac t Moldin g Processes . Draf

t Report . Prepare d fo

r U.S . EPA , Nationa

l Ris k Managemen

t Researc h Laboratory . Researc h Triangl e Park , NC . Septembe

r 1995 . 5 . Duffy , M.J. , Ashland Chemica l Company . Styren e Emission s - Ho w Effectiv e are Suppresse d Polyester

Resins ? 34t

h Annua l Technica l Conference , Reinforce d Plastics/Composite s Institute , Th e Societ y o f th e Plastic s Industry . 1979 . 6 . Reducin g Styren e Emission s in Fibe r Reinforce d Plasti c Operations . Minnesota Technica l Assistanc e Program , Minnesot aOffic e o f Wast e Management . March 1993 . 7 . Memorandum . Strum , M. , U.S . EPA , to Pre-MAC T Team/Wor k Grou p Members . July 21 , 1995 . Reminde

r o f upcomin g pre-MAC T teleconference . Enclosure : Cook Composite s and Polymers , 962-WA-19 6 Lo w VOC/Buffbac

k Whit e Ge l Coat . 8 . Memorandum . Strum , M. , U.S . EPA , to Pre-MAC T Team/Wor k Grou p Members . Septembe r 15 , 1995 . Summar

y o f Jul y 31 , 199 5 teleconference . 9 . D e Koning , A.J . 'INSERT ' Resins ; A Break-through i n th e Reductio n o

f Styrene Emissio n Durin g Open-Moul d Processing . DS M Resin s BV , Zwolle , Th e Nether

lands . Apri l 1995 . 10 . DS M Halve s Styren e Emission s wit h Insert . Reinforced Plastics . Jun e 1995 . p . 14 . 

# 3 >P.3 5

Madelein e Stru

mDRAF T Octobe r 23 , 199 5 Pag e 3 2 11 . Reinforce d Plasti c Composite s Pollutio n Preventio n Focu s Grou p Meetin g (meetin g summary) . Organize d b y Organic s Contro l Branch , Ai r & Energy Engineerin g Research Laboratory , U.S . EPA . Research Triangl e Park , NC . Septembe r 13 , 1993 . p . 10 . 12 . Hovan , G.R. , GLS Corporation . Th e Epox y Alternative . Composite s Fabrication . Februar y 1995 . p . 9-10 . 13 . Referenc e 11 , p . 10-12 . 14 . Referenc e 11 , p . 12-13 . 15 . Referenc e 2 , p . 40 . 16 . Referenc e 2 , p . 48 . 17 . Referenc e 2 , p . 44 . 18 . Phas e I Emissio n Study . Pultrusio n Industr y Council , SPI Composite s Institute . Ma y 3 , 1993 . 19 . Referenc e 2 , p . 51-54 . 20 . Referenc e 2 , p . 56 . 21 . Letter

and enclosure s fro

mTunis , Georg e C , Hardcore DuPon t Composites , L.L.C. , Ne

w Castle , DE , to Strum , Madeleine , U.S . Environmenta l Protectio n Agency , Researc h Triangl e Park , NC . Octobe r 11 , 1995 . 22 . Referenc e 2 , p . 62 . 23 . Open-Molde d Thermoset Composite s ar e Replaced . Plastic s Brie f - Reinforce d Plastic s Newsletter . Vol . XIX , No . 16 . Marke t Searc h Inc . Augus t

7 , 1995 . 24 . Polic y Statemen

t on Reducing Ai r

Emission s fro

mOpe n Moldin g Composite s Fabrication . Composite s Fabricator s Association . Septembe r 1993 . 

## 3 H