esaform2008_tan.pdf

8/14/2019 esaform2008_tan.pdf

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1 INTRODUCTION

The injection stretch blow moulding (ISBM !rocess

is the m"in method used to m"ss#!roduce $%T

bottles& Now"d"'s modelling techniues )or the

ISBM !rocess h"*e become incre"singl' im!ort"nt

in o!timising !roducts "nd !rocesses& $rocess

modelling is used to obt"in better insight into the

!rocess o!er"tion in order to identi)' the critic"l

!rocessing condition which gi*es " !roduct with

o!timum u"lit'& This reduces tri"l "nd error

e+!eriment"tion,reduces new !roduct turn"roundtime "nd c"n be used to reduce bottle weights b'

determining the o!timum distribution o) m"teri"l in

the bottle )or mech"nic"l "nd b"rrier !er)orm"nce&

This !"!er t"-es " ste! b"c- )rom the de*elo!ment

o) ISBM simul"tion "nd "ims to in*estig"te the

in)l"tion o) !re)orm in )ree "ir& This is somewh"t

sim!ler to simul"te th"n the re"l !rocess "s

modelling cont"ct with the mould "nd stretch rod is

not reuired& The )ree blow "nd )ree stretch blow

e+!eriments "lso o))er the o!!ortunit' to me"sure

the !rocess in much more det"il th"n th"t c"n be)ound when in)l"ting " !re)orm inside " mould&

. %/$%RIM%NT0 2OR3

4ree blow e+!eriments were c"rried out on "n

instrumented !rotot'!e de*elo!ed in C%M%4 using

m"r-ed !re)orms "ccording to !rotocols de)ined in

!re*ious studies 51,.6& T47 gr"de m"teri"l

(I89:&;


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4ig& .? $re)orm tem!er"ture distribution

Once the !re)orm h"s been he"ted to " !re#de)ined

tem!er"ture,it w"s tr"ns)erred to " stretch#blow

m"chine,where it w"s subjected to " stretch blowing

!rocess ()ree blow e+!eriment in*ol*es onl'

blowing st"ge& 4igs& H "nd >" show the e*olution o)

!re)orm sh"!e "nd the corres!onding !ressure#

*olume *s& time cur*e )or )ree blow e+!erimentwhilst 4igs& "nd ;" show the e*olution o) !re)orm

sh"!e "nd the corres!onding !ressure#*olume *s&

time cur*e )or )ree stretch blow e+!eriment& 0 -e'

!oint to note is the r"!id in)l"tion o) the !re)orm

coinciding with " r"!id di! in the !ressure&

0ddition"l e+!eriments showed th"t this cur*e

*"ried with di))erent !re)orm tem!er"ture !ro)iles

"nd m"gnitude o) "!!lied nomin"l !ressure&

s :&::s :&:=>s :&11.s :&1>: s :&.:1s :&s :&::s :&:=s :&11.s :&1>1s :&.:1s :&


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H

The !re)orm sh"!e e*olution o) the simul"ted result

using const"nt m"ss )low r"te method w"s )ound to

closel' m"tch the e+!eriment"l results (4ig& ;& The

bubble initi"tes "nd in)l"tes "t "lmost the s"me time

(:&: CONCUSIONS

%+cellent *olume *s& time cur*e "nd !re)orm

e*olution !ro)ile "re obt"ined in both the )ree blow

"nd )ree stretch blow simul"tions onl' in the c"se

when const"nt m"ss )low r"te is used to model the

blowing "ir in the simul"tion& This indic"tes th"t

"!!l'ing the !ressure *i" " m"ss )low r"te o) "ir is

the most "!!ro!ri"te method to model the !ressure

inside the !re)orm& Considering "ssum!tions )or

tem!er"ture, e+!eriment"l error "nd )low r"te

c"lcul"tions correl"tion between e+!eriment "nd

simul"tion )or both )ree blow "nd )ree stretch blow

is e+cellent& This *"lid"tes the simul"tionde*elo!ment,m"ss )low r"te c"lcul"tion,m"teri"l

model "nd the ch"r"cterised const"nts )or the )ree

blow "nd )ree#stretch blow tri"ls&

R%4%R%NC%S

1 orlier %&,$hD Thesis,%cole des Mines de $"ris (4r"nce,

.::1&

. orlier %&,E"udin G&M&,0g"ss"nt G&4&,e!"ge G&&,$ere

&,D"rr"s D&,Billon N&,Hth Intern"tion"l %S04ORM

Con)erence on M"teri"l 4orming .::1,iege,Belgium&

Documents

esaform2008_tan.pdf