p. 1


# OAR Box 

# 1413 Prepped by Ollie Stewart



## Document

Number: 

# 22 ) 11-1-2 2 Docket Number: 

# A-94-5 2

Printed 7/9/2008 3:11:21 PM

Sheet 22 of 114P. 2 

# w RUG-15-199 5 10:3 8 DS M RESIN S 70S649677 7 P.1 6 

### DS M Resin s 

## HrJ'lZ DS M t- J 

# f ?

• i r > ] 

# n Th e advantages ca n b e summarise

d a s follows : Workers ar

e expose d t o lowe rstyren e concentration s durin g processin g Reduce d styren e emission i n th e curin g stag e

, Les s pollutio n o

fth e environment Reductio n o

fth e styren e emissio n is reached withou t affectin g processi biiit yan d produc

t propertie

s Materia l saving s ar

e achieve d becaus e oflowmonome revaporatio n N o interlamina radhesio n problems ; lon g curin g times betwee n consecu tive lay-up s ar

e possible Becaus e o fth e lowe rstyren e emission s ne wlegislativ e requirements ma

y b e me t wit h n o orlimite

d additiona l investments i n ventilation , whil e purificatio n o

fth e exhaus

t ai rwil l not b

e necessary , i n orue rt

o mee t tri e stringen t MA- Vvaiue s u is noweve rrecomrnenoe u i o pa y attentio n to prope rhousekeeping , efficien t ventilation , an d usin g th e righ t processin g equipment . DS M Resin s is witlin g t o advise yo u o n these aspects . DS M Resins continues it s development

s into resin s wit h a lowstyren e emissio n durin g open-moul d processing . Base d o n th e technolog ywhic h ha s bee n extensivel ydescribed i n thi s paperth e rang e ofresin s fo rhan d lay-up , spray-u p an d filamen t windin g wil l b e extended . Thi s no

t onl yincludes othe rortho - an d is o U P resins , bu t also th e hig h performanc e bispheno l A an d viny l este rresins . Additionally , INSERTwil l b e use d t o develo p lowstyren e emissio n gelcoats . Th e preliminar

yresults i n thi s applicatio n are a too k ver ypromising . 

## ACKNOWLEDGEMEN T Th e autho rthank

s P . Dijkin k

and M . Lueske n fo rthei rvaluabl e contributio n i n developin g th e INSER

Tconcept . Minimu m



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### . "~ ^ DS M 1 $ DS M Resin s « i

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### ^ H •B^^^^* * •M B B i\\\\\\\\m

mmmmmmmmmmmmmmmmmmm-\--m\--m---m-------m-^^^^BB--^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 

## INTRINSIC

STYRENE

EMISSION

REDUCTION

TECHNOLOGY

i
i



## INSER T A break-throug h i n th e reductio n o fstyren e emissio n durin g open-moul d processin g Dr . A.J . de Koning R DS M Resins fl JEC , Apri l 199 5 U

•—^^^*-\ •. !, „ i i , : J J*- J I I <
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•flUG-15-199 5 10=3 4 DS M RESIN S 706849677 7 P.0 3 DS M Resin s DS M l- J

* 1 

# u 'INSERT'

Resins; a break-through

in the reduction

of styrene emission

during open-mould

processing Dr. A.J. de

Konlng DSM Resins BV. Z-voffe, The

Netherlands April 1335



## " I J 

## ABSTRAC T

Healt h an d environmenta l problem s are receivin g a n increasin g amoun t o f attention . Th e worksho p atmosphere a s wel l a s th e ventilate d ai ri n th e GR P industr yar e seriousl yaffecte d by th e styren e emissio n o funsaturate d polyeste r resins . Fro m a toxicologica l an d performanc e poin t o fvie wsuitabl e alternative s ar e lacking , s o styren e continue s t o b e th e monome ro fchoic e i n th e unsatura te d polyeste ran d viny l este rindustry . Durin g th e fabricatio n o freinforce d plastic s composite s on e ca n distinguis h betwee n th e processin g stag e (e g sprayin g an d rolling ) an d th e setting/curin g stag e whe n th e resi n i s a t rest . Th e well-know n Lo wStyren e Emissio n (LSE ) resins , whic h suppres s monome remissio n b y th e formatio n o fa fil m acros s th e surfac e o fth e laminate , are mainl yeffectiv e i n th e setting/curin g stage . Durin g sprayin g and/o rroll-ou t i n open-moul d processes , whe n th e surfac e o fth e resi n i s continuousl ydisturbed , emission s are hardl yless tha n thos e o fth e bas e resi n withou t a fil m formin g additive . DS M Resin s ha s conducte d a ver yIntensive researc h progra m t o specificall y reduc e th e styren e emissio n i n th e processin g stage . Th e effec t o fresi n propertie s suc h a s polyme rstructure , monome rcontent , molecula rweight , viscosity , an d reactivit yo n styren e emissio n have bee n thoroughl yinvestigated . Throug h a basi c understandin g o fth e chemical - an d physica l phenomen a o fth e evaporatio n proces s a ne wconcep t fo rresin s wit h a reduce d styren e emissio n ha s bee n developed . Thi s concep t has bee n calle d 'INSERT' , meanin g INtrinsi c Styren e Emissio n Reductio n Technology . Th e ne wSynolit e 550 0 serie s base d o n INSER T show s a reductio n ofth e styren e emissio n i n th e processin g stag e o fabou t 50 % withou t detrimen t t o th e eas e o ffabricatio n an d produc t properties . Mechanica l characteristics , HD Tan d wate rresistanc e o fth e glas s fibr e reinforce d product s ar e consisten t wit h thos e o ftypica l U P resins . Throug h thi s emergin g technolog yth e use o fUnsaturate d Polyeste rresin s i n open-moul d processin g continue s t o hav e a viabl e future . Usin g thes e ne wresi n system s ma ylimi t o reve n preven t additiona l investment s i n extractio n an d ai r purificatio n t o compl ywit h th e more stringen t rules o flegislation . 

## MP. 5

•fiUG-15-199 5 10:3 5 DS M RESIN S 706849677 7 P.0 4 DS M Resin s 

## INTRODUCTIO N DS M | $ l i

Th e legislatio n i n Europ e wit h regard t o styren e emissio n int o th e workplac e an d th e environmen t has becom e mor e stringen t i n th e las t decade . Althoug h long ter m bioassay s an d epidemiologica l studie s amongs t more tha n 65,00 0 peopl e wh o worke d i n thei rprofessiona l life i n th e polyeste rindustry , d o no t sho wan y conclusiv e evidenc e ofcarcinogeni c effect s relate d t o styrene , th e politica l pressur e t o reduc e emission s i s stil l on . Ther e ar.e severa l reason s fo rthat :

•Upo n exposure t o styren e i n concentration s wel t abov e 5 0 pp m acut e healt h effect s suc h as ski n an d ey e irritation s a s wel l a s neurotoxi c effect s (narcosis) ar

e known . Thes e effects , despit e th e fac t tha t the y ar e completel yreversibl e (i.e . th e huma n bod yrecover s withou t an yadvers e chroni c healt h effects) , negativel yaffect s th e huma n workin g conditions .
•Ther e i s a genera l polic yt o reduce th e emission s o fvolatil e organi c com pound s (VOCs , a chiefIngredien t i n smo g formation ) int o th e environ ment . Styrene . however , has a shor t atmospheri c half-lif e characteristi c ( 2 t o 5 hours) . It s effec t o n th e uppe ratmospher e an d eve n a t ground leve l i n th e formatio n ofsmo g i s minimal . Th e mai n sourc e ofstyren e emission s i s th e polyeste rindustry . Abou t hal fo fth e U P resi n volum e i s processed i n open-moul d technique s suc h a s han d lay-up , spray-up , an d filamen t winding . Hereb ysignifican t emission s occur ; fo rinstanc e durin g laminatin g approximatel y5- 7 % i n weigh t o fth e resi n i s los t becaus e o f styren e evaporation . I n industria l practic e thi s ma yproduc e a n exposur e whic h i s greate rtha n th e curren t MA C (Maximu m Allowe d Concentration ) o rTWA-TL V (Tim e Weighte d Averag e •Threshol d Limi t Value) . Moreover , th e emissio n o f styren e result s i n a n increase i n th e materia l cost s ofproduction , an d ma y negativel yaffec t th e mechanica l propertie s o fth e product . Th e polyeste rindustry , confronte d wit h thi s seriou s problem , i s intensivel y lookin g a t technica l possibilities t o achieve a substantia l reductio n i n th e emissio n o fstyrene . Thi s includes modification s o fresins , proces s technologies , applicatio n techniques , wor k practices , an d installatio n o fadd-o n emissio n treatmen t devices . Althoug h i n al i thes e field s significan t progres s ha s bee n mad e th e subject o fthi s pape rwil l b e restricte d t o developmen t o fimprove d resins . Introductio n o fth e well-know n LS E (LowStyren e Emission ) resin s I n th e secon d hal fo fth e seventie s wa s th e firs t importan t ste p i n combatin g styren e emissio n a t th e source . Th e LS E resin s contai n a smal l quantit yo fwa xo rparaffi n tha t i s jus t solubl e i n th e resin . Upo n evaporatio n o fa limite d amoun t o fstyren e th e fil m formin g additive separate s an d form s a thi n laye ro n th e surfac e o fth e polyester , thereb yblockin g furthe rstyren e emission . Th e proble m o fa poo r interlamina radhesio n betwee n consecutive applie d laminat e layer s wa s over - 

### :.. i

I V IE . 

# i
1P. 6

flUG-15-1995 10=35 DSMRESIN S

DS M Resin s ?0684yb7Y 7 H'.U b DS M ®

com e b yth e additio n ofadhesio n promotors i n th e secon d generatio n o fLS E resins . Thes e LS E resins , representin g th e stat e o fth e ar t i n styren e emissio n reductio n technology , are no wuse d t o a wid e extent . Th e LS E resins , however , are onl yeffectiv e i n th e curin g o rstati c stage . I n th e precedin g dynami c phas e ofsprayin g an d roll-ou t th e barrie rparaffi n fil m i s continuousl ydisrupte d an d therefor e hardl yactive . A s th e majo rpar t o fth e tota l styren e emissio n take s place i n th e activ e laminatin g ste p o fth e proces s th e overal l efficienc yofLS E resin s i s rathe rlimited . n^ M Orntin * t>. a - , « ...wijoiou wnei u tfirort t o develo p resin s whic h als o exhibi t a reduce d styren e evaporatio n i n th e dynami c phas e o fth e process . Thes e investigation s have resulte d i n a ne wserie s o fresin s wit h a ver ylo w styren e emissio n durin g (an d after ) open-moul d processing . 

## RESI N DEVELOPMEN T Th e targe t wa s t o develo p resin s whic h durin g activ e lamination , th e mos t criti ca l stag e o fth e contac t mouldin g process , give of ffa rles s styrene . Severa l route s wer e explored : / . Alternative

monomers. Althoug h chemicall y(partial ) replacemen t o fstyren e i s a viabl e option , ther e are restriction s fro m physical , toxicologica l an d economica l point s o fview . Styren e remain s th e bes t choic e a s a monome rgivin g ris e t o polyester s whic h handl e well , cure readily , an d giv e products wit h goo d propertie s a t a competitiv e price . 2. Resins

in which the solubility

parameter

of the unsaturated polyester

matches

that of styrene. Apar t fro m th e fac t tha t th e chemica l possibilitie s t o obtai n suc h resin s ar e ver y limited , th e effec t o n styren e emissio n reductio n wa s less tha n anticipated . 3. Resins

with a reduced

styrene content. I n a typica l genera l purpose unsaturate d polyeste rresi n th e percentag e o fnon volatil e polyeste rcomponen t i s i n th e rang e o f55-60 % an d henc e lha t o f styren e monome r40-45% . A decreas e i n th e molecula rweigh t o fth e unsatura te d polyeste rresult s i n a decreas e i n viscosity o fth e solution s i n styren e an d enable s resin s o fa lowe rstyren e content , an d henc e a lowe revaporatio n rate , t o b e used . However , whe n startin g fro m conventiona l polyester s n o resin s wit h a styren e conten t lowe rtha n 30-3 5 % ca n be produce d wit h sufficien t mechani ca l strength , chemica l resistance , an d workabl e viscosity .

*1/ flUG-15-1995 10:3 5 DS M RESIN S DS M Resin s 706849677 7 P.0 6 DS M & P. 7

Nevertheless . DS M Resin s succeede d by specia l processin g an d formulatin g t o produc e a lo wviscosityresi n wit h a styren e conten t o fonl y25% . havin g processin g characteristic s simila rt o standar d U P resins . Moreover , th e mechani ca l an d physica l characteristic s o fth e cure d product s ressembl e thos e o fth e classica l UP's . Th e ne wproprietarytechnology , has bee n calle d 'INSERT' . INSER Ti s th e acrony m o fINtrinsi c Styren e Emissio n Reductio n Technology . Throug h 'INSERT' , emission s i n bot h th e dynami c an d stati c phas e o fth e productio n proces s ca n b e reduce d by50% . Whe n 'INSERT ' I s combine d wit h th e well-know n 'LSE ' technolog y eve n furthe r reduction s i n styren e emission s ca n b e obtaine d i n th e curin g stage . INSER Tforme d th e basi s fo ra ne wgeneratio n o fresin s suitabl e fo ropen-moul d processe s suc h as han d lay-up , spray-up , chop-hoop , an d filamen t winding . i 

### I



## NE WPRODUCT

S DS M Resin s introduce s th e firs t resin s i n th e ne wrang e o fproducts . SYNOLIT E 5520-1- 1

SYNOLIT E 5520-P- 1 Pre-accelerate d genera l purpos e laminatin g resin . Thi s thixotropi c resi n shows a goo d glas s fibr e we t ou t an d i s designe d fo ruse i n genera l spra ydepositin g wor k a s wel l a s rolle ran d brus h applications . Th e resi n has a mediu m reactivit yan d show s a lo wpea k exother m upo n curing . Because o f'INSERT ' i t exhibit s a lo w styren e emissio n i n bot h th e dynami c an d stati c phas e o fth e productio n process . A n 'LSE ' versio n o fSynolit e 552 0 wit h a n eve n furthe r reductio n o fth e styren e emissio n i n th e curin g phase . ! t

Th e ke yfeatur e ofthes e ne wresin s i s a majo rreductio n o fth e styren e emissi on , especiall yI n th e dynami c stag e o fth e conversio n process . Th e styren e evaporatio n o fSynolit e 5520-1- 1 i n th e stati c o rcurin g phas e i s als o significantl y lowe rtha n tha t o fno n LS E resins . However , t o get th e maximu m resul t i n tota l styren e emissio n reductio n th e us e o fa n LS E version , Synolit e 5520-P-1 , i s recommended .

i ; t.flUG-15-199 5 10:3 6 DS M RESIN S



### DS M Resin s 7UbbS43bYY Yl-'.'d V 

### DS M 1 $ P. 8



### Typica l liqui d resi n propertie s

[-•^^•••••

« 

### Propert y Uni t Syn . 552 0 Standardortho UP resin s Genera l Reactivit y purpos e lo

w mediu

m Vise , a t 2 3 * C Thix . index Styren e conten t Aci dnumbe r Ge l tim e Densit y (2 0 »C ) mPa. s

m g KOH/ g min . kg/m 1 250-35 0

2.2-3. 2 2 5 17-2 2 13-1 8 112 0 190-24 0 240-31 0

2.5-3. 5 2.5-3. 5 4 3 

### 22-2 7 19-2 3 109 0 4 2

11-1 7 20-2 5 110 0 Tabl e 1
. Typica l liqui d resi n propertie s o fSynolit e 552 0 an d (comparable )

conventiona l orth o resin s fo ropen-moul d processes . Despit e th e fac t tha t Synolit e 552 0 onl ycontain s 2 5 % o fstyren e i t ha s a very lo wviscosit ysuitabl e fo rhan d lay-u p an d spray-u p processing , an d rapi d fibr e we t out . Viscosit yan d ge l tim e ca n b e tailore d t o th e specifi ccustome rre quirements
. t



# I I 1 1

II. -



### * n 5



## 6 . iP. 9

.RUG-15-199 5 10=3 6 DS M RESIN S cKIOCWS O <<<r . -ao 

# t

r DS M Resin s

Typica l physica l propertie s o fcas t unfille d resi n DS M &

Propert y Uni t Syn . 552 0 Standar d orth o U PResin s 

# Reactivit y lo w mediu

m Tensil e strength Tensil e modulu s Tensil e elongatio

n Flexura l strength Flexura l modulu s Impac t strength (Unnocche

dCharpy ) HD T (ISO 75A ) Barco l hardnes s MP a GP a * 

### KP a GP a kJ/m » 7 0 3. 0 3. 2 11 5 3. 1 7. 0 7 5 4 4 6 5

3. 4 2. 4 9 5 3. 5 8. 0 6 5 4 4 Tabl e 2
. Typica l cure d cas t propertie s o fSynolit e 552 0 an d conventiona l

orth o resin s fo rcontac t mouldin g processes . Remarkably
. Synolit e 552 0 exhibit s mechanica l propertie s tha t d o no t deviat e fro m thos e o fth e well-know n genera l purpos e tesins. Aspecia l advantag e offere d b ythi s resi n i s th e lo wdegre e o fshrinkage , resultin g i n les s fibr e print through
. Becaus e styren e give s th e highes t contributio n t o shrinkag e reducin g it s conten t i n th e resi n infiuenche s thi s characteristic
. A s Synolit e 552 0 contain s onl y25 % o fstyren e th e volum e shrinkag e i s 1.5-2. 0 % les s tha n tha t o f conventiona l U P resins
.

•.AUG-15-199 5 10=3 6 DS M RhblN S IUOOH3D I I I r . t o 

### DS M Resin s DS M 1 $ P.1 0 ?.*.; > j. i ,i 

### Typica l propertie s d flaminate s (containin g 30 % Choppe d Stran d Mat ) 1 Propert y

. 

### Tensil e strength Tensil e modulu s Flexura l strength Flexura l modulu s Wate r absorptio

n (ISO-R-175 ) afte r 2 4 hour s afte r 7 days afte r 2 1 days Uni t



### MPa GP a KP a GPa

% % 

### Syn . 552 0



### 10 0 7. 6 18 0 7. 0
0.1 0 0.2 5 0.4 0 standard

UP Resin s ortho 

## Reactivity . lo w mediu

m 

### 10 5 7. 9 18 0 7. 2 12 5

8. 0 20 5 7. 4
0.1 0 0.3 0 0.4 5 

# 1 Tabl e 3 . Typica l laminat e propertie

s o fSynolit e 552 0 i n compariso n t o thos e o fstandar d orth o resins . Also th e laminat

e propertie

s o fSynolit e 552 0 ar

e i n accordance wit h thos e o f genera l purpos

e laminatin g resins . Becaus e ofth e lo

wstyren e conten t ofth e resi n th e pea k

exother m i s wel l controlled enablin g th e productio n ofrelativel y thic k laminate s i n one step . Th e wate rabsorptio n o fth e laminate

s doe s no t exceed that ofcurrentl y availabl e (LSE

) resins whic h ar

e Lloyd' s an d De

t Norsk e Verita s (DNV) approved . !
. '
. .



# I ; Ii 

### J f

<


### I n tabl e 4 th e minima l technica l requirement s ar e defined fo rLloyd's . De t Norsk e Veritas . (DNV) , and th e classificatio n type 112 0 accordin g t o DI N 16946 . Wha n 

### values o fSynolit e 5520 , a

s presente

d i n tabl e 2 and 3 , i t i s eviden t tha t ou r ne wlaminatin g resin , easilymeet s th e requirement

s ofth e marin e specifyin g authorities . Test

s ar e underwa

yt o ge t th e officia l approvals . Fro m thes e result

s i t i s evident that no technica l concession s hav e t o b e made fo rthi s ne

wrange o

fresins wit h a lowstyren e emissio n durin g open-moul d processing . >.s.V 'P.1 1

HULa-lD-iyy S itl-O D LOI' I IXC' S i IN S 

# t DS M Resin s DS M | $


# I P '1 3 Property Uni t Lloyd' s DN V



# J

, 5


# fa Cas tre ain .

Tensil e strengt h Tensil e modulu s * Tensil e elongatio n Flexura l strengt h HO T (IS0-75A ) Barco l hardnes s Laminat e Tensil e strengt h Tensil e modulu s Flexura l strengt h Flexura l modulu s MP a GP a * 

### MP a

• c 2. 0

5 5 4 0 4 5

3. 0 1. 5
6 2 3 5
MP a GPa MPa GPa 7 5

4. S 14 5 4. 5 8 0

7. 0 13 0 6. 0 OI N1694 6

Typ e 112 0
6 0
2. 0 11 0 5 5

Tabl e 4 . Minima l technica l requirement s fo rcas t resi n an d laminate propertie s accordin g to Lloyd's , DN V an d DI N 16946 . 

### Styren e emissio n A lo t ofnon-resi n relate

d factor s hav e a n influenc

e o n th e styren e emission , suc h as ambient temperature , spee d o fai rflo wove rth e resi n o rlaminate , moul d geometry , type o

fspra ygun , tim e o

fprocessing , laminat

e thicknes s an d ge l time . Moreover , background emissions ma yb e present whic h i n case ofdirec t styren e detectio n measurement s ma ygiv e wron g results . I n orde rt o dra wvali d conclusion s i t is therefor e o futmos t importanc

e t o conduc

t th e experiments underidentica l workin g conditions . * i I F c

:*- i 

# n 1. Laboratory scale experiments A firs t an d quic k

screenin g to investigat

e whethe ro rno

t a newresi n exhibits a lowe rstyren e emission tha n th e referenc e materia) , is throug h th e determinatio n

vi: - •RUG-15-199 5 10:3 ? 

### DS M Resin s Db M KtblN b ftJOCiH^ O I I f 

## DS M ft P.1 2



### ofth e stati c weigh t los s o fth e uncatalyse

d resin . Thi s typ e o

fmeasurement i s ver

ysimple . 5 0 gram s o

fth e U P resi n is poure

d onto a ti n dis h wit h a diamete ro f13. 5 cm , givin g a polyeste rlaye rwit h a thickness o

fapproximatel y3 m m an d a surfac e o f14 3 cm 1


### . Th e filled dis h i s placed o n a balanc

e an d th e weigh t los

s is followe d i n time . Th e styren e emissio n i s expresse

d i n g/m a 

### . Thes e measurement

s were don e a t 2 3 ° C i n a closed thermostate d spac e wit h a wel l defined constan t ai rflow . I n figur e 1 th e stati c styren e emission s o fa standar d U P resin , a standar

d LSE resin , Synolit

e 5520-1- 1 (ISERT) . an d Synolite 5520-P- 1 (th e LSE versio n o fSynolit e 5520-1-1 ) ar

e compared . 

## 15 0

E 10 0 f 

# 1 % 50+ - Standar d U P /

INSERT^ . / * ... . Standaid-LS E ..*** —-•••uiiiiliuiiiiniilllllillllllllim'IIII W 

# ^—f 1- UMSERT-LSE 1 0 

## f 2 0 3 0 Tim e (min ) 

# -t 4 0 5 0 Figur e 1 . Stati c styren e emissio n o funcatalysed laminatin g resins ; standar d UP , standar

d LSE , INSER

T(Synolit

e 5520-1-1) . an d INSERT-LS E (Synolit e 5520-P-1. ) Fo rth e standar

d U P resi n th e styren e los s is linea rove rth e 5 0 minutes period . Th e styren e evaporatio n spee d o fth e INSER

Tresin , Synolite 5520-1-1 , i s sig nificantl ylower . Th e styren e los s versu s tim e plo

t slightl ydeviates fro m th e linea rbehaviour . A

s th e mechanis m o

fINSER Tca n b e explained throug h th e formatio n ofintermolecula rinteraction s thi s i s i n lin e wit h expectations . Th e standar d U P an d Synolit

e 552 0 hav

e similarviscosities despite th e fac t thei r styren e conten t differ

s considerably , viz . 4 3 an d 2 5 % o n tota l resi n weight , 

## J

1 0PUG-15-lSy b 10:.} ? DSf l RESIN S lUDOHDQl| ( r.l l



### DS M Resin s DS M It P.1 3

: 1 • M respectively . Whe n th e LS E technolog yi s applie d t o Synolit e 552 0 th e lowes t styren e emissio n curv e i s obtained . Afte r2 0 minute s more o rles s th e sam e emissio n leve l ha s bee n reache d wit h th e standar d LSE-U P resin , howeve rit s emissio n curv e clearl ydiffers . I n cas e o fth e Standar d LS E resi n th e fil m formatio n o fth e LS E additiv e i s complet e withi n a fe wminute s afte rwhic h th e styren e evaporati o n virtuall ystops . Th e barrie ro n Synolit e 5520-P- 1 o n th e contrary , develop s graduall yi n time . Mayb e thi s les s abrup t fil m formation , leavin g mor e roo m fo r ai rinhibitio n a t th e surface , i s th e reaso n fo rth e goo d interlamina radhesio n of laminate s involvin g a laps e of2 4 hours betwee n th e firs t an d secon d layer . Althoug h thes e simpl e laborator yexperiment s give a n indicatio n o fho weffecti v e ne wdevelopment s maybe , th e rea l proofofcours e ha s t o com e fro m styren e concentratio n measurement s durin g actua l moulding . 2. Spray-up

experiments Th e followin g tes t wa s devise d byDS M Resin s t o simulat e laminatio n i n a workshop . I n th e spray-boot h o fou rTechnica l Centr e i n Zwoli e a serie s o f garde n pond s wa s mad e wit h differen t resin s a s matrix . Th e productio n proces s consiste d o fthre e sprayin g an d consolidatio n step s (tota l operatio n tim e 1 5 minutes ) followed byth e curin g phase . Th e spray-u p techniqu e wa s chose n becaus e i t i s know n tha t mor e tha n hal fofth e tota l styren e emissio n take s plac e i n th e dynami c phas e o fthi s applicatio n process . Continuou s monitorin g o fth e evaporate d styren e wa s don e usin g a photo ionisatio n detecto rdirectl yinsid e th e stac k o n to p o fth e spray-boot h whil e th e extractio n fan s wer e running . Fo rreliabilityo fthes e experiment s i t wa s o f paramoun t importanc e tha t the y wer e conducte d unde ridentica l circumstances . Al l experiment s wer e don e i n duplicate . Thre e differen t resins , al l havin g a ge l tim e o f3 5 minutes , wer e selected . Th e U P resin s wer e a standar d orthophthali c spray-u p resin , a n LS E versio n ofth e previou s resin , an d th e newl ydevelope d Synolit e 5520-P-1 . Fo rclarit yth e proces s has bee n 'mathematically ' divide d int o thre e stages , viz . th e cumulativ e sprayin g operatio n (1) , th e tota l tim e o fconsolidatio n (2) , an d th e laminat e curin g (3) . Thi s wa s don e t o ge t a n insigh t o fth e styren e evapora tio n o fth e differen t proces s phases o n th e tota l emission . Th e result s o fth e experiment s ar e presente d graphicall yi n figur e 2 . t

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# i i DS M Resin s Ltol' l KfoiN D I W—>*W~- 1 -/ W< 

### DS M l* J 

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Spray-u p o fa garde n pon d

INSERT-LS

E Standard-LS E Standard-U P i J



### Th e followin g conclusion s ca n b e drawn : i r Figur e 2 . Compariso n ofa standar d U P resin , Standar

d LS E resin , an d INSER TLSE Resins (Synolit

e 5520-P-1 ) b

ymeasuremen t o

fatmospheri c styren e durin g th e productio n process .

Abou t tw o third s o

fth e tota l styren e emission occur s i n th e dynami c phase . However , i t mus t b e noted that thi s rati o i s dependan t o n th e type ofproduc

t an d th e ge l tim e ofth e resin . Onl yi n th e curin g phas e doe s th e LS E resi n giv

e a lowe rstyren e emissio n tha n th e standar

d resin . Th e fil m formin g additiv e i s not activ

e durin g sprayin g an d roll-ou t o

fth e laminate .

1 2 

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Vm\ 

# ?3 rP.1 5

RUG-15-199 5 10:3 8 DS M RESIN S ••/UbfcWybVV Yr.1 4



### . DSMResin s DS M 1 $ !| ! A A

•' •Th e styren e emissio n o fSynolit e 5520-P- 1 i n th e stati c phas e t s compa - •rabl e t o tha t ofth e LS E resin . . " I A t th e momen t severa l fiel d trial s a t customers are i n progres s t o reaffir m th e

result s o fstyren e emissio n reductio n i n practice . 

## J 

# 1 

# 1 1 1 Interlamina radhesio n studie s Resin s containin g fil m formin g additives , i n particula rth e firs t generatio n LS E resins , hav e buil t u p a ba d reputatio n i n th e marke t plac e wit h regar d t o poo r interlamina radhesion . Sinc e Synolit e 5520-P- 1 contain s a n LS E additiv e t o obtai n th e optimu m reductio n i n styren e emission , it s effec t o n secondar y bondin g wa s thoroughl ystudied .



### 1 3 •i i •u Th e INSER Tresi n gives 50 % less styren e emissio n tha n bot h th e standar d I an d th e LS E resi n i n th e dynami c phas e o fth e process. •

r 

### i ; i< i' 

# w l i

! ; i \ A serie s o flaminate s wer e mad e bylaying-u p fou rlayer s o f45 0 g/m 2 choppe d stran d ma t togethe rwit h eac h resi n an d leavin g thi s fo ra define d perio d t o cur e befor e a furthe rfou rlayers ofglas s ma t an d resi n wer e applied . Th e surfac e o f. ] th e botto m laminat e laye rwa s eithe rglass-ric h o rresin-rich . ;

Th e laminate s wer e subjecte d t o th e classica l pee l test , an d th e mor e advance d , \ Doubl e Canteleve rBea m tes t (Europea n Grou p o n Fractur e proposa l fo rinterla - . mina rfractur e toughnes s testin g o fcomposite s - Marc h 1990) . J ; Th e pee l tes t give s a goo d Qualitativ e impressio n o fth e secondar ybonding , whil e •accordin g t o interna l investigation s - th e DC 8 tes t provide s th e mos t reli abl e Quantitativ e results . Bot h th e short bea m flexura l tes t (IS O 4585 ) an d la p shea rtes t (AST M 3163 ) whic h wer e als o evaluate d wer e les s discriminatin g betwee n a goo d an d ba d interlamina radhesion . Th e DC B tes t determine s th e energ ytha t i s require d fo rth e crac k propagatio n o fa specime n i n whic h delaminatio n I s initiate d throug h a fil m place d betwee n th e laminat e layer s durin g moulding . Th e require d energ yt o obtai n a certai n crac k length , divide d b yth e surfac e are a o fth e crack , i s a measure ofth e interlamina radhesion . Th e INSER Tresin s have bee n compare d wit h standar d polyester s containin g n o wa xo rparaffin , an d LS E resins . Laminate s base d o n Synolit e 5520-P- 1 giv e a n excellen t interlamina radhesion . Eve n afte ra laps e o fon e wee k crac k propagati o n energ yvalue s o f> 85 % tha n tha t ofth e referenc e wet-on-we t mad e laminat e wer e obtained . Thes e value s correspon d t o thos e o fth e orth o U P resin s withou t fil m former . Th e conventiona l LS E resins , however , showe d lowe r results . A laminatin g interva l o f2 4 hours alread yresulte d i n a reductio n o fth e secondarybondin g b y30-4 0 % . Thi s wa s th e cas e bot h wit h DS M an d compe titiv e resin s whic h wer e evaluated .

*.* . r.s Jf i i'P.1 6

-AUG-15-199 5 10:3 6 DS M RESIN S 706649677 ? P.1 5

DS M Resin s DS M t $

t 

## L 

# n

. - 1 Th e DC B tes t thu s indicate s a goo d secondar ybondin g fo rlaminate s base d o n Synolit e 5520-P-1 . Th e DC B value s o fSynolit e 5520-1- 1 (no n LSE) resi n an d Synolit e 5520-P- 1 d o no t differ . I n th e pee l tes t th e laminat e layer s base d o n th e INSER Tresin s wer e onl ypeele d of fwit h considerabl e effor t an d wit h a lo t o f fibr e tea rfro m th e surfaces . 

## CONCLUSIO N DS M Resin s ha s launche d th e firs t i n a ne wgeneratio n o fpolyeste rresin s fo r open-moul d processin g techniques . Thes e resin s featur e lo wstyren e emission s no t onl yi n th e stati c o rcurin g stag e bu t als o durin g lamination , whil e maintai nin g th e physica l propertie s o fexistin g high-standar d products , especiall y wit h regar d t o produc t performanc e an d interlamina radhesion . Bot h laboratorystudie s an d actua l worksho p evaluation s prov e tha t th e ne w resin s hav e reduce d monome rlos s int o th e workplac e an d henc e int o th e surroundin g environment . Synolit e S520-I- 1 i s a pre-accelerate d thixotropi c polyeste rresi n speciall y designe d fo rhan d lay-up , spray-up . an d chop-hoo p applications . Throug h th e applicatio n o fa ne wtechnology . INSERT , a styren e emissio n reductio n o f approximatel y50 % i s achieve d withou t th e use o fparaffin s o rwaxe s a s filmformers . SynoUte 5520-P- 1 contain s additionall ya n LS E additive . However , i n combinati o n wit h INSER Tn o problem s wit h respect t o interlamina radhesio n ar e encounte red . * i

Thes e resin s are commerciall yavailabl e a t a smal l premiu m whe n compare d t o standar d products . Althoug h th e resin s are thu s somewha t mor e expensiv e significan t saving s ma ybe gaine d i n lowe rcos t extractio n system s an d th e avoidanc e o fai rpurificatio n techniques . Moreover , bearin g i n min d tha t th e custome rha s actuall ypai d th e pric e o fresi n fo rth e styren e tha t evaporates , saving s are als o obtaine d throug h th e reductio n i n th e los s o finitia l styrene .



### 1 4 • j

# r AUG-15-199 5 10:3 8 DS M RESIN S 706849677 ? P.1 6 

### DS M Resin s DS M &



# h 

# n
p 

# p

3 Th e advantages ca n b e summarise

d a s follows : Workers ar

e expose d t o lowe rstyren e concentration s durin g processin g Reduced styren e emissio n i n th e curin g stag e

.. Les s pollutio n o

fth e environmen t Reductio n o

fth e styren e emissio n is reache d withou t affectin g processi bilit y an d produc

t propertie

s Materia l saving

s ar e achieved becaus

e oflo wmonome revaporatio n N o interlamina radhesio n problems ; lon g curin g time s betwee n consecu tive lay-ups ar

e possible Becaus e o fth e lowe rstyren e emission s newlegislativ e requirements ma

y b e met wit h no o rlimited additiona l investment s i n ventilation , whil e purificatio n o

fth e exhaus

t ai rwil l no

t b e necessary , i n orue ri o mee

t tri e stringent IVIM C 

### vaiues i t i s noweve rrecornrnenoeo i o pa y attentio n t o prope rhousekeeping , efficien t ventilation , an d usin g th e righ t processin g equipment . DS M Resins i s willin g t o advis e yo u o n thes e aspects . DS M Resin s continue

s it s development

s into resin s wit h a lowstyren e emissio n durin g open-moul d processing . Base d o n th e technolog ywhic h has bee n extensivel ydescribe

d i n thi s paperth e rang e ofresin s fo rhan d lay-up . spray-u p an d filamen t windin g wil l b e extended . Thi s no

t onlyincludes othe rortho - an d iso U P resins , bu t als

o th e hig h performanc

e bispheno l A an d viny l este rresins . Additionally , INSER

Twil l b e use d t o develo p lowstyren e emissio n gelcoats . Th e preliminar

yresult s i n thi s applicatio n are a loo k ver ypromising . 

## ACKNOWLEDGEMEN T Th e autho rthank

s P. Dijkin k

an d M . Lueske n fo rthei rvaluabl e contributio n i n developin g th e INSER

Tconcept .

1 6