tips for defect-free extrusion of tpu...thermal degradation of material. dwell time in cylinder or...
TRANSCRIPT
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2 1
Tips for Defect-FreeExtrusion of TPU
Covestro Deutschland AGCHEMPARK DormagenAlte HeerstraßeBuilding F2941538 Dormagene-mail: [email protected]
desmopan.com
This information and our technical advice – whether verbal, in writing or by ways of trial – are given in good faith but without warranty, and this also applies where pro-prietary rights of third parties are involved. The information is provided by Covestro without assumption of any liability. If any of the above mentioned regulations change after the date of declaration, this dec laration is no longer valid. Covestro will strive to keep this information up-to-date. Our advice does not release you from the obliga-tion to verify the information provided – especially that contained in our safety data and technical information sheets –, to check for updates of any information provided by us and to test our products as to their suitability for the intended processes and uses. The application, use and processing of our products and the products manu-factured by you on the basis of our technical advice are beyond our control and, therefore, entirely your own responsibility. Our products are sold in accordance with the current version of our General Conditions of Sale and Delivery.
Edition: 2016 · Order-No.: COV00080667 · Printed in Germany
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2 3
Vario
us p
robl
ems
can
aris
e w
hen
extr
ud-
ing
ther
mop
last
ics
– an
d th
at g
oes
for
TPU,
to
o. W
e ha
ve c
ompi
led
an e
xten
sive
list
of
poss
ible
def
ects
, exp
lain
ed th
eir c
ause
s an
d de
scrib
ed p
reve
ntiv
e m
easu
res.
To
help
you
fin
d th
em m
ore
easi
ly, w
e ha
ve d
ivid
ed t
he
defe
cts
into
gro
ups,
suc
h as
“Def
ects
cau
sed
by m
oist
ure”
or “
Def
ects
com
mon
ly a
ssoc
iat-
ed w
ith b
low
n fil
ms”
. Ple
ase
do n
ot h
esita
te to
co
ntac
t us
if th
is li
st d
oes
not h
elp
you
solv
e yo
ur p
robl
em.
We
wou
ld b
e gr
atef
ul fo
r an
y hi
nts,
sug
ges-
tions
and
illu
stra
tions
you
cou
ld s
ubm
it to
m
ake
this
cat
alog
ue o
f de
fect
s m
ore
com
-pl
ete.
Tip
s fo
r def
ect-
free
ext
rusi
on o
f TPU
1. 1
.1
Gen
eral
def
ects
4
1.2
Defe
cts
caus
ed b
y m
oist
ure
131.
3 De
fect
s co
mm
only
ass
ocia
ted
with
18
ca
stin
g an
d fla
t film
s1.
4 De
fect
s co
mm
only
ass
ocia
ted
with
22
bl
own
film
s1.
5 De
fect
s co
mm
only
ass
ocia
ted
with
34
ho
ses
1.6
Defe
cts
com
mon
ly a
ssoc
iate
d w
ith
45
profi
les
-
4 5
Caus
es:
Rem
edie
s:
Drye
r dirt
yCh
eck
drye
r for
fore
ign
mat
eria
l, cle
an
Drye
r filte
r sys
tem
def
ectiv
eCh
eck
and
repa
ir sy
stem
Wea
r deb
ris fr
om c
onve
yor
Chec
k an
d re
pair
syst
em
Exce
ssiv
e du
st fo
rmat
ion
in m
ater
ial p
repa
ratio
n
or e
xtru
sion
are
asKe
ep a
ll mat
eria
l con
tain
ers
tight
ly s
eale
d un
til
need
ed
Fore
ign
mat
eria
l in e
xtru
der
Rins
e or
mec
hani
cally
cle
an e
xtru
der a
nd m
old
Caus
es:
Rem
edie
s:
Inco
rrect
tem
pera
ture
pro
file
Adju
st te
mpe
ratu
res
Poor
mix
ing
Incr
ease
cou
nter
pres
sure
. Incr
ease
num
ber o
r de
nsity
of s
cree
ning
sta
ck. U
se s
tatic
mixe
r
Thro
ughp
ut to
o fa
stRe
duce
scr
ew s
peed
Con
tam
inat
ed e
xtru
date
1.1
Gen
eral
def
ects
Des
crip
tion:
Spe
cks
and
spot
s on
ext
ruda
te
Des
crip
tion:
Spe
cks
and
spot
s on
ext
ruda
te
Gel
mat
ter i
n ex
trud
ate
-
6 7
Caus
es:
Rem
edie
s:
Dwel
l tim
e to
o lo
ngIn
crea
se th
roug
hput
Scre
w a
t a s
tand
still
Allo
w s
crew
to c
ontin
ue ro
tatin
g sl
owly.
Pu
rge
with
Des
mop
an® 3
85 /
Texi
n™ 2
85 a
nd
then
shu
t dow
n
Dead
spo
ts in
mol
d / a
dapt
erO
ptim
ize m
old
and
adap
ter
Des
crip
tion:
Har
d fla
kes,
usu
ally
whi
te, o
f diff
eren
t size
s ar
e flu
shed
out
at
irre
gula
r int
erva
ls
Whi
te fl
akes
in e
xtru
date
Caus
es:
Rem
edie
s:
Ther
mal
deg
rada
tion
Opt
imize
mol
d an
d ad
apte
r. Re
duce
mel
t te
mpe
ratu
re.
Redu
ce d
wel
l tim
e. R
educ
e fri
ctio
n.
Clea
n or
cle
ar d
ead
spot
s m
ore
frequ
ently
Moi
stur
eSe
e “M
oist
ure-
rela
ted
defe
cts”
Des
crip
tion:
Stre
aks
and
blis
ters
on
the
surfa
ce
Str
eaks
and
blis
ters
on
the
surf
ace
-
8 9
Caus
es:
Rem
edie
s:
Fore
ign
mat
eria
l in e
xtru
der m
akin
g m
ater
ial
inco
mpa
tible
Purg
e or
mec
hani
cally
cle
an e
xtru
der a
nd m
old
Inco
mpa
tibilit
y w
ith a
dditi
ve b
atch
esUs
e ap
prop
riate
add
itive
bat
ches
Diffe
rent
vis
cosi
ties
mak
ing
mat
eria
ls in
com
patib
leDo
not
mix
diff
eren
t bat
ches
of s
ame
mat
eria
l
Tem
pera
ture
too
high
(deg
rada
tion)
Redu
ce te
mpe
ratu
re
Poor
hom
ogen
izatio
n
Adju
st te
mpe
ratu
re p
rofil
e. In
crea
se p
ress
ure
in
front
of d
ie.
Chec
k sc
rew
pro
file
and
use
mor
e su
itabl
e sc
rew
if
nece
ssar
y. Ad
just
mat
eria
l thr
ough
put t
o ex
trude
r ca
paci
ty
Des
crip
tion:
Ext
ruda
te h
as ir
regu
lar s
truc
ture
Non
-hom
ogen
eous
mel
ting
Caus
es:
Rem
edie
s:
Ther
mal
deg
rada
tion
of m
ater
ial. D
wel
l tim
e in
cy
linde
r or m
old
too
long
. Mel
t tem
pera
ture
to
o hi
gh
Redu
ce m
elt t
empe
ratu
re. R
educ
e dw
ell t
ime
in
cylin
der o
r mol
d
Redu
ce s
hear
Chec
k al
l con
trolle
rs a
nd h
eatin
g ba
nds
Des
crip
tion:
Dar
k or
silv
ery
area
s vi
sibl
e on
mat
eria
l
Dis
colo
red
mat
eria
l
-
10 11
Caus
es:
Rem
edie
s:
Mat
eria
l the
rmal
ly d
amag
ed. D
wel
l tim
e in
cyl
inde
r or
mol
d to
o lo
ng. M
elt t
empe
ratu
re to
o hi
gh
Redu
ce th
erm
al lo
ad o
n m
elt.
Redu
ce d
wel
l tim
e
in c
ylin
der o
r mol
d. R
educ
e m
elt t
empe
ratu
re
Redu
ce s
hear
Caus
es:
Rem
edie
s:
Brid
ging
in h
oppe
r (de
fect
ive
conv
eyan
ce)
Redu
ce te
mpe
ratu
re o
f fee
d zo
ne (c
heck
coo
ling)
Unsu
itabl
e sc
rew
des
ign
Use
anot
her m
ater
ial o
r a d
iffer
ent s
crew
Us
e a
groo
ved
feed
bus
h
Back
pre
ssur
e in
scr
ewAd
just
tem
pera
ture
pro
file
or u
se re
vers
ed
tem
pera
ture
pro
file
Des
crip
tion:
Stro
nger
than
usu
al o
dors
(typ
ical
or a
typi
cal o
f mat
eria
l)
Des
crip
tion:
Hig
hly
fluct
uatin
g ou
tput
of m
elt
Unu
sual
sm
ell
Pul
sing
-
12 13
Caus
es:
Rem
edie
s:
Brid
ging
in h
oppe
rRe
duce
tem
pera
ture
of f
eed
zone
Feed
zone
too
hot
Redu
ce te
mpe
ratu
re o
f fee
d zo
ne
No g
roov
ed b
ushi
ng in
feed
zone
Chan
ge fe
ed zo
ne
Des
crip
tion:
Ext
rude
r sho
ws
insu
ffici
ent t
hrou
ghpu
t rat
e
Poo
r fee
d-in
Caus
es:
Rem
edie
s:
Mat
eria
l or p
igm
ent p
aste
too
moi
stCh
eck
drye
r and
con
veyo
r sys
tem
. Co
ver h
oppe
r
Des
crip
tion:
Ext
ruda
te h
as s
ilver
-col
ored
stre
aks
in d
irect
ion
of fl
ow
1.2
Moi
stur
e-re
late
d de
fect
s
Sur
face
str
eaks
-
14 15
Caus
es:
Rem
edie
s:
Mat
eria
l or p
igm
ent p
aste
too
moi
stCh
eck
drye
r and
con
veyo
r sys
tem
. Co
ver h
oppe
r
Des
crip
tion:
Ext
ruda
te e
xhib
its s
mal
l blis
ters
and
stre
aks
Blis
ters
on
surf
ace
Caus
es:
Rem
edie
s:
Mat
eria
l or p
igm
ent p
aste
too
moi
stCh
eck
drye
r and
con
veyo
r sys
tem
. Co
ver h
oppe
r
Des
crip
tion:
The
ext
ruda
te e
xhib
its s
ink
mar
ks a
nd c
aviti
es
Voi
ds in
thic
k-w
alle
d ex
trud
ates
-
16 17
Caus
es:
Rem
edie
s:
Mat
eria
l or p
igm
ent p
aste
too
moi
stCh
eck
drye
r and
con
veyo
r sys
tem
.Co
ver h
oppe
r
Des
crip
tion:
Sur
face
of e
xtru
date
is ro
ugh
and
unev
en
Rou
gh s
urfa
ce
Caus
es:
Rem
edie
s:
Too
muc
h m
oist
ure
in m
ater
ial o
r pig
men
t pas
te
caus
ing
fluct
uatio
ns in
vis
cosi
ty.
Chec
k dr
yer a
nd c
onve
yor s
yste
m.
Cove
r hop
per
Des
crip
tion:
Ext
ruda
te d
imen
sion
s ca
nnot
be
accu
rate
ly s
et; d
imen
sion
s va
ry c
ontin
ually
Dim
ensi
onal
var
iatio
ns
-
18 19
Caus
es:
Rem
edie
s:
Stre
tch
ratio
too
high
Redu
ce s
ize o
f die
slo
t. In
crea
se th
roug
hput
Tem
pera
ture
s to
o hi
ghRe
duce
mel
t tem
pera
ture
Film
adh
eres
to th
e ro
llIn
crea
se a
mou
nt o
f rel
ease
age
nt
Chan
ge ro
ll tem
pera
ture
Cha
tter
mar
ks
1.3
Def
ects
aff
ectin
g ca
st a
nd fl
at fi
lms
Des
crip
tion:
Mar
ks o
r lat
eral
stre
akin
g on
film
sur
face
Caus
es:
Rem
edie
s:
Stre
tch
ratio
too
high
Redu
ce s
ize o
f die
slo
t. In
crea
se th
roug
hput
Tem
pera
ture
in la
st h
eatin
g zo
ne to
o lo
wIn
crea
se te
mpe
ratu
re in
last
hea
ting
zone
Des
crip
tion:
Edg
es o
f film
are
torn
at i
rregu
lar i
nter
vals
, at r
ight
ang
les
to d
irect
ion
of e
xtru
sion
Tor
n ed
ges
-
20 21
Caus
es:
Rem
edie
s:
Mol
d di
rty
Clea
n in
side
of m
old
and
die
lip
Mol
d in
corre
ctly
adj
uste
dAd
just
pre
ssur
e sc
rew
s
Tem
pera
ture
var
iatio
nsCh
eck
tem
pera
ture
con
trol
Tem
pera
ture
too
high
Redu
ce te
mpe
ratu
res
Des
crip
tion:
Mar
ks o
n fil
m in
dire
ctio
n of
flow
Str
eaki
ng o
n fil
m s
urfa
ce
Caus
es:
Rem
edie
s:
Roug
hnes
s of
sub
stra
te la
yer
Incr
ease
laye
r thi
ckne
ss. C
hang
e su
bstra
te
mat
eria
l
Des
crip
tion:
Sur
face
of c
oatin
g ex
hibi
ts s
mal
l “cr
ater
s” a
nd h
oles
Hol
es
-
22 23
Caus
es:
Rem
edie
s:
Insu
ffici
ent q
uant
ity o
f ant
i-blo
ck a
dditi
ve o
r in
corre
ct a
nti-b
lock
add
itive
use
dCh
eck
quan
tity
and
type
of a
nti-b
lock
add
itive
Win
ding
tens
ion
too
high
Adju
st w
indi
ng te
nsio
n. F
it de
flect
ing
rolle
rs w
ith
own
driv
e
Insu
ffici
ent c
oolin
g an
d / o
r am
bien
t tem
pera
ture
to
o hi
ghRe
duce
out
put.
Exte
nd c
oolin
g se
ctio
n.
Use
cool
ed a
ir fo
r coo
ling
Blo
ckin
g of
film
1.4
Def
ects
aff
ectin
g bl
own
film
s
Des
crip
tion:
Film
is d
ifficu
lt to
unw
ind
or w
ind
arou
nd
Caus
es:
Rem
edie
s:
Air s
peed
from
coo
ling
ring
too
high
Redu
ce a
ir th
roug
hput
Lip
open
ing
of c
oolin
g rin
g to
o sm
all
Enla
rge
lip o
peni
ng
Fric
tion
in c
olla
psin
g bo
ards
Mod
ify s
urfa
ce o
f col
laps
ing
boar
ds to
redu
ce
frict
ion.
Red
uce
mel
t tem
pera
ture
Des
crip
tion:
Bub
ble
does
not
pas
s sm
ooth
ly th
roug
h co
llaps
ing
boar
ds
Cha
tter
ing
in fi
lm o
r bub
ble
-
24 25
Caus
es:
Rem
edie
s:
Inco
rrect
mat
eria
l typ
eUs
e co
rrect
mat
eria
l
Extru
sion
tem
pera
ture
too
high
or t
oo lo
wAd
just
tem
pera
ture
pro
file
Insu
ffici
ent fi
lm c
oolin
gCh
eck
cool
ing
syst
em
Film
too
thic
k
Redu
ce fi
lm th
ickn
ess
Poor
mix
ing
due
to la
ck o
f she
ar in
ext
rude
r an
d m
old
Chec
k ex
trude
r and
mol
d.
Incr
ease
cou
nter
pres
sure
Des
crip
tion:
Film
is m
ilky
or c
loud
y
Poo
r film
tran
spar
ency
Caus
es:
Rem
edie
s:
Depo
sits
on
lip o
f die
Clea
n lip
of d
ie. A
pply
thin
coa
ting
of s
ilicon
e
grea
se to
lip o
f die
Hard
par
ticle
s or
fore
ign
mat
eria
l in m
old
Clea
n bl
ow m
andr
el a
nd u
pper
sec
tion
of m
old.
Cl
ean
cond
uit a
rea
belo
w d
ie
Insu
ffici
ent m
ixin
g of
mel
t flow
sIn
crea
se c
ount
erpr
essu
re in
ext
rude
r. In
crea
se te
mpe
ratu
re o
f ada
pter
and
mol
d.
Use
finer
scr
een
to in
crea
se c
ount
erpr
essu
re
Des
crip
tion:
Film
exh
ibits
stre
akin
g in
dire
ctio
n of
flow
Mar
ks o
r dro
plet
s on
bub
ble
-
26 27
Caus
es:
Rem
edie
s:
Film
edg
es c
url in
bef
ore
rolle
r nip
sAd
just
nip
to c
olla
psin
g fra
me.
Ad
just
late
ral fi
lm s
lidew
ays
Caus
es:
Rem
edie
s:
Unev
enne
ss o
f die
slo
tCh
eck
die
slot
and
adj
ust
Unev
en a
ir sp
eed
in c
oolin
g rin
gAd
just
air
flow
rate
by
adju
stin
g co
olin
g rin
g
Unev
en d
ie ri
ng te
mpe
ratu
reEn
sure
eve
n te
mpe
ratu
re d
istri
butio
n
Extru
der p
ulsa
tes
See
“Pul
satin
g”
Unev
en s
peed
of t
ake-
off ro
llers
Chec
k dr
ive
of ta
ke-o
ff ro
llers
Loos
e ch
ain
driv
eAd
just
cha
in d
rive
Bubb
le d
oes
not e
xpan
d in
coo
ling
ring
area
Incr
ease
inne
r bub
ble
pres
sure
. Red
uce
cool
ing
outp
ut
Des
crip
tion:
Film
edg
es a
re w
avy
and
sagg
ing
Des
crip
tion:
Ree
l of fi
lm e
xhib
its “p
isto
n rin
gs”
Sag
ging
film
edg
es
Flu
ctua
tions
in fi
lm th
ickn
ess
-
28 29
Caus
es:
Rem
edie
s:
Poor
bub
ble
geom
etry
Redu
ce n
ip h
eigh
t to
colla
pse
film
bef
ore
nip
at a
hi
gher
tem
pera
ture
(80°
C -
110°
C)
Unev
en c
oolin
g of
bub
ble
Chec
k dr
awpl
ate
cont
act.
Chec
k la
tera
l film
sl
idew
ays
Blow
-up
ratio
too
low
Incr
ease
blo
w-u
p ra
tio
Thin
are
as in
film
Adju
st d
ie
Extru
sion
tem
pera
ture
too
high
or t
oo lo
wG
radu
ally
adj
ust t
empe
ratu
re
Des
crip
tion:
Stre
ngth
or s
tabi
lity
of b
ubbl
e no
t ade
quat
e
Bub
ble
exhi
bits
insu
ffici
ent s
tabi
lity
Caus
es:
Rem
edie
s:
Film
com
es in
to c
onta
ct w
ith a
uxilia
ry e
quip
men
t
Chec
k th
e fo
llow
ing
units
: - B
ubbl
e gu
ide
- Col
laps
ing
fram
e - T
reat
men
t uni
t - N
on-d
riven
rolle
r - D
anci
ng ro
ller
- Sid
e gu
sset
ing
unit
- Film
fold
ing
unit
- Cut
ting
blad
e ho
lder
- M
echa
nica
l equ
ipm
ent f
or e
limin
atin
g st
atic
ch
arge
s Ch
eck
film
tens
ion
Des
crip
tion:
Sur
face
scr
atch
es in
dire
ctio
n of
flow
Scr
atch
es
-
30 31
Caus
es:
Rem
edie
s:
Insu
ffici
ent c
oolin
gCh
eck
cool
ing
sour
ce
Mel
t too
col
dIn
crea
se te
mpe
ratu
re
Blow
-up
ratio
too
high
Mod
ify b
low
-up
ratio
Inad
equa
te w
eld
line
stre
ngth
Adju
st te
mpe
ratu
re p
rofil
e
Dirt
par
ticle
s be
low
or i
nsid
e di
e lip
sCh
eck a
nd c
lean
die
lips
Des
crip
tion:
Bub
ble
colla
pses
Bub
ble
colla
pses
Caus
es:
Rem
edie
s:
Web
tens
ion
fluct
uate
s or
is to
o hi
ghCh
eck
and
redu
ce w
eb
tens
ion
whi
le re
el is
be
ing
wou
nd
Esca
pe o
f air
from
bub
ble
Chec
k w
heth
er a
ir is
esc
apin
g at
air
conn
ectio
n po
int o
n m
old
Pum
ping
or b
reat
hing
of b
ubbl
eCh
eck
whe
ther
col
laps
ing
fram
e is
pos
ition
ed
too
clos
e. C
heck
whe
ther
air
spee
d in
coo
ling
ring
is to
o hi
gh
Film
web
mig
rate
s in
infe
ed a
rea
of w
indi
ng s
tatio
nCh
eck
web
tens
ion
Fluc
tuat
ing
web
tens
ion
in tr
imm
ing
or s
littin
g st
atio
n Ch
eck
web
tens
ion
Mel
t too
vis
cous
Incr
ease
die
hea
d te
mpe
ratu
re
Des
crip
tion:
Req
uire
d fil
m w
idth
is n
ot a
chie
ved
or fl
uctu
ates
sig
nific
antly
Une
ven
wid
th
-
32 33
Caus
es:
Rem
edie
s:
Mar
ked
fluct
uatio
ns in
thic
knes
s of
film
web
Ensu
re e
ven
die
open
ing,
coo
ling
air s
peed
and
di
e te
mpe
ratu
re
Insu
ffici
ent c
oolin
g, u
nsta
ble
bubb
leUs
e co
oler
air
or in
crea
se v
olum
e of
air
to in
crea
se
bubb
le c
oolin
g
Lack
of a
lignm
ent i
n co
llaps
ing
boar
ds a
nd
prim
ary
nip
rolle
rs in
rela
tion
to th
e di
e
Ensu
re c
lean
infe
ed in
to c
olla
psin
g bo
ards
. El
imin
ate
draf
ts a
roun
d bu
bble
. Al
ign
colla
psin
g bo
ards
and
prim
ary
nip
rolle
r so
as
to e
nsur
e ev
en w
indi
ng te
nsio
n an
d sm
ooth
film
web
Rolle
rs in
corre
ctly
alig
ned
Real
ign
rolle
rs
Des
crip
tion:
Film
wra
p ex
hibi
ts w
rinkl
es a
nd w
arpi
ng
Wrin
klin
g
Exce
ssiv
e w
eb te
nsio
n or
too
man
y no
n-dr
iven
ro
llers
Ch
eck
web
tens
ion
and
spee
d of
dow
nstre
am
rolle
rs
Roug
h su
rface
s in
col
laps
ing
fram
e ar
eaEl
imin
ate
roug
h su
rface
s
Unev
en c
olla
psin
g of
bub
ble
Adju
st c
olla
psin
g bo
ards
and
late
ral fi
lm g
uide
. M
inim
ize m
ovem
ent o
f bub
ble
by re
duci
ng d
is-
tanc
e be
twee
n ou
tput
of b
ubbl
e an
d co
llaps
ing
boar
ds
-
34 35
Caus
es:
Rem
edie
s:
Air b
ubbl
es o
n su
rface
of h
ose
in w
ater
bat
hCo
ol w
ith la
rge,
slo
w c
asca
de o
f wat
er
Des
crip
tion:
Hos
e ex
hibi
ts s
mal
l dep
ress
ions
on
surfa
ce
1.5
Def
ects
aff
ectin
g ho
ses
Sin
k m
arks
Caus
es:
Rem
edie
s:
Wat
er d
ropl
ets
on s
urfa
ce in
air
cool
ing
zone
Prot
ect h
ot h
ose
from
spl
ashe
s
Des
crip
tion:
Bul
ging
cau
sed
by s
hifti
ng o
f mel
t
Bul
ging
-
36 37
Caus
es:
Rem
edie
s:
Dam
p m
ater
ial
Dry
mat
eria
l. Che
ck d
ryer
. Fog
mat
eria
l in h
oppe
r w
ith n
itrog
en
Low
mel
t tem
pera
ture
Incr
ease
mel
t tem
pera
ture
Dirt
y di
eCl
ean
die.
App
ly th
in c
oatin
g of
silic
one
gr
ease
to d
ie
Mel
t fra
ctur
e on
the
die
Incr
ease
mel
t tem
pera
ture
. Use
die
with
long
er
cond
uits
. Use
die
with
sm
alle
r inn
er in
take
ang
les
to c
ondu
it ar
ea
Des
crip
tion:
Dep
osit
form
ing
on d
ie is
tran
sfer
red
to m
ater
ial
Rou
gh in
ner o
r out
er fa
ces
Insu
ffici
ent m
ixin
g
Incr
ease
mel
t pre
ssur
e Re
duce
scr
ew te
mpe
ratu
re
Redu
ce s
crew
spe
ed
Chec
k sc
rew
geo
met
ry
Fille
r con
tent
too
high
Redu
ce fi
ller c
onte
nt
Unsu
itabl
e fil
ler
Repl
ace
fille
r
-
38 39
Caus
es:
Rem
edie
s:
Perio
dic
back
pre
ssur
e on
man
drel
/ di
eIn
crea
se te
mpe
ratu
re o
f man
drel
/ di
e
Vibr
atio
n in
take
-off
unit
Repa
ir ta
ke-o
ff un
it
Des
crip
tion:
Hos
e ex
hibi
ts th
ick
area
s at
irre
gula
r int
erva
ls
Per
iphe
ral b
ead
(insi
de /
outs
ide)
Caus
es:
Rem
edie
s:
Wel
d lin
es fa
il due
to in
suffi
cien
t mel
t tem
pera
ture
or
exc
essi
ve e
xtru
sion
spe
ed o
r low
die
lip
pres
sure
Incr
ease
mel
t tem
pera
ture
. Ex
tend
dw
ell t
ime.
Incr
ease
vis
cosi
ty in
die
lip a
rea.
Us
e di
e w
ith lo
nger
con
duit
to d
evel
op m
ore
pr
essu
re
Thin
poi
nts
Read
just
die
Des
crip
tion:
Hos
e te
ars
at w
eld
lines
Tea
r in
hose
wal
l
-
40 41
Caus
es:
Rem
edie
s:
Puls
atin
g m
ater
ial fl
owUs
e a
smal
ler i
nitia
l cal
ibra
tion
unit.
Che
ck u
nit f
or
wea
r and
not
ches
. Rep
air o
r rep
lace
if n
eces
sary
Unev
en c
asca
de o
f wat
erEn
sure
eve
n flo
w o
f wat
er a
roun
d ho
se
Insu
ffici
ent m
ixin
g
Incr
ease
mel
t pre
ssur
e.
Redu
ce s
crew
tem
pera
ture
. Re
duce
scr
ew s
peed
. Us
e a
bette
r des
ign
of s
crew
Des
crip
tion:
Hos
e ex
hibi
ts th
ick
area
s at
regu
lar i
nter
vals
Per
iphe
ral w
ave
Caus
es:
Rem
edie
s:
Ove
rhea
ted
or c
old
area
s in
mol
dAd
just
mol
d te
mpe
ratu
re.
Alig
n ta
ke-o
ff un
it
Take
-off
unit
poor
ly a
ligne
d to
mol
dCe
nter
man
drel
Des
crip
tion:
Wal
l thi
ckne
ss u
neve
n ov
er c
ross
-sec
tion
Une
ven
wal
l thi
ckne
ss
-
42 43
Caus
es:
Rem
edie
s:
Calib
ratin
g eq
uipm
ent i
n w
ater
bat
h de
fect
ive
or
def
orm
edRe
plac
e ca
libra
ting
equi
pmen
t
Hose
is to
o w
arm
Redu
ce w
ater
tem
pera
ture
in c
oolin
g ba
th
Caus
es:
Rem
edie
s:
Dam
p m
ater
ial
Dry
mat
eria
l. Che
ck d
ryer
. Fog
mat
eria
l in h
oppe
r w
ith n
itrog
en
Mel
t tem
pera
ture
too
low
Incr
ease
mel
t tem
pera
ture
. Cle
an d
ie.
Appl
y th
in c
oatin
g of
silic
one
grea
se to
die
Des
crip
tion:
Hos
e ha
s a
mat
t sur
face
Des
crip
tion:
Hos
e is
out
of r
ound
Hos
e ou
t of r
ound
Lac
k of
glo
ss
-
44 45
Caus
es:
Rem
edie
s:
Die
tem
pera
ture
too
high
Redu
ce d
ie te
mpe
ratu
re
Use
mat
ting
batc
h
Des
crip
tion:
Hos
e ha
s a
glos
sy s
urfa
ce
Hos
e to
o gl
ossy
Caus
es:
Rem
edie
s:
Too
muc
h or
too
little
trac
tion
on p
rofil
eM
odify
take
-off
spee
d or
mat
eria
l tem
pera
ture
Des
crip
tion:
Des
ired
dim
ensi
ons
are
not a
chie
ved
1.6
Def
ects
aff
ectin
g pr
ofile
s
Inc
orre
ct d
imen
sion
starget
actual
-
46 47
Caus
es:
Rem
edie
s:
Unev
en m
old
tem
pera
ture
s Ad
just
tem
pera
ture
s. In
sula
te m
old
Des
crip
tion:
Pro
file
exhi
bits
cor
rect
dim
ensi
ons
but i
ncor
rect
ang
les
Ske
wed
cro
ss-s
ectio
ntarget
actual
Caus
es:
Rem
edie
s:
Insu
ffici
ent c
oolin
gEn
sure
that
coo
ling
is e
ven
and
supp
ort p
rofil
e
until
coo
l eno
ugh
to re
tain
sha
pe b
y its
elf.
Redu
ce th
roug
hput
Mat
eria
l too
dam
pM
easu
re m
ater
ial d
ampn
ess
and
dry.
Prot
ect m
ater
ial f
rom
moi
stur
e
Des
crip
tion:
Dim
ensi
on a
nd a
ngle
of p
rofil
e co
rrect
whe
n pr
oduc
t le
aves
die
, but
cha
nge
durin
g po
st-t
reat
men
t
Def
orm
ed p
rofil
etarget
actual
-
48 49
Caus
es:
Rem
edie
s:
Cont
amin
atio
n on
die
Clea
n di
e. A
pply
thin
coa
ting
of s
ilicon
e gr
ease
to
die
Die
too
cold
Incr
ease
tem
pera
ture
of d
ie.
Incr
ease
ext
rude
r tem
pera
ture
Mel
t fra
ctur
e –
exce
ssiv
e ou
tput
spe
ed a
t die
Redu
ce s
peed
of e
xtru
der a
nd ta
ke-o
ff un
it.
Use
mol
d w
ith m
ore
stre
amlin
ed in
feed
, larg
er
open
ing
or lo
nger
con
duits
Mol
d is
scr
atch
ing
mat
eria
lPo
lish
insi
de o
f mol
d
Des
crip
tion:
Sur
face
exh
ibits
too
little
glo
ss o
r is
roug
h
Low
glo
ss
Caus
es:
Rem
edie
s:
Dirt
y di
eCl
ean
die
Notc
h or
pre
ss s
eam
in ta
ke-o
ff sy
stem
or m
old
Elim
inat
e sc
ratc
hes
Des
crip
tion:
Lin
es in
dire
ctio
n of
flow
Mar
ks
-
50 51
Caus
es:
Rem
edie
s:
Extru
date
is to
o ho
t whe
n it
reac
hes
the
conv
eyor
Cool
und
ersi
de o
f pro
file
with
air
befo
re it
com
es
into
con
tact
with
bel
t. Bl
ow a
ir th
roug
h ho
les
in
belt
onto
pro
file
Des
crip
tion:
Pro
file
exhi
bits
irre
gula
r dep
ress
ions
Sin
k m
arks
-
52 53
Not
es
-
Not
es
54 55