Prejudices about polyamide for multilayer films
-
Upload
ted-brink -
Category
Technology
-
view
191 -
download
8
Transcript of Prejudices about polyamide for multilayer films
![Page 1: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/1.jpg)
Prejudices about
Polyamide in multilayer filmsTed Brink 17 June 2015
![Page 2: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/2.jpg)
Page 2 Polyamide in multilayer film - PPS 2015
Contents
• polyamide structure
• processing
• polyamide in barrier applications
• conclusions
![Page 3: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/3.jpg)
Page 3
Prejudices
![Page 4: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/4.jpg)
Page 4 Polyamide in multilayer film - PPS 2015
Prejudices about polyamide
• moisture is difficult to control
• processing temperature is too high
• PA6 not suitable for blown film
• a PE-layer is required for good oxygen
barrier
![Page 5: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/5.jpg)
Page 5
Structure
![Page 6: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/6.jpg)
Page 6
The amide group
![Page 7: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/7.jpg)
Page 7
Most common polyamides for extrusion
PA66
And PA6.66 copolyamide
PA6
![Page 8: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/8.jpg)
Page 8 Polyamide in multilayer film - PPS 2015
Melting points of PA6.66, PA6 and PA66
PA6.66 PA6 PA66
190
220
255
melt
ing
po
int
[°C
]
![Page 9: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/9.jpg)
Page 9 Polyamide in multilayer film - PPS 2015
Influence of PA6/PA66 ratio on the melting point
0 25 50 75 100150
175
200
225
250
275
PA66 [%]
melt
ing
po
int
[°C
]
100 % PA6
100 % PA66PA6.66(85/15 %)
![Page 10: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/10.jpg)
Page 10 Polyamide in multilayer film - PPS 2015
Polyamide comparison
melting point
crys-tallinity
barrier clarity puncture resis-tance
price0
1
2
3
PA66PA6PA6.66lowest
highest
medium
relative comparison
![Page 11: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/11.jpg)
Page 11 Polyamide in multilayer film - PPS 2015
Moisture absorption of PA6.66, PA6 and PA66
PA6.66 PA6 PA660
2
4
6
8
10
12
50 % RHin water
H2
O c
on
ten
t [%
m
/m] at 23 °C
![Page 12: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/12.jpg)
Page 12 Polyamide in multilayer film - PPS 2015
Thermal properties of PA6
0
50
100
150
200
250
300
processing range
crystal growth
melting point
glass transition temperaturetem
pera
ture
[°C
]
![Page 13: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/13.jpg)
Page 13 Polyamide in multilayer film - PPS 2015
Crystallization of polyamide
• at fast cooling rates: no crystallization
• at low cooling rates: large crystals
• presence of nucleant: small crystals
postcrystallization when Tg below ambient conditions
![Page 14: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/14.jpg)
Page 14
Why use polyamide?
![Page 15: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/15.jpg)
Page 15
Main reasons to use polyamide
O2
mechanical strength oxygen barrier
![Page 16: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/16.jpg)
Page 16 Polyamide in multilayer film - PPS 2015
Oxygen versus moisture barrier
0.01 0.1 1 10 1000.01
0.1
1
10
100
1000
10000
water permeation at 23 °C and 85 % RH [g/m²•day]
oxyg
en
perm
eab
ilit
y
(ml•
cm
/m
²•d
ay•b
ar)
x1
00 LDPE
EVOH 32 %EVOH 38 %
EVOH 44 %
PA6
PVDC
BOPET
BOPP
film thickness 100 µmmeasured at 23 °C
![Page 17: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/17.jpg)
Page 17 Polyamide in multilayer film - PPS 2015
O2 permeability of PA6 related to humidity and temperature
0 25 50 75 1000
25
50
75
100
5 °C
23 °C
40 °C
relative humidity [% RH]
oxyg
en
perm
eab
il-
ity (
ml•
cm
/m
2•d
ay•b
ar)
x1
00
![Page 18: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/18.jpg)
Page 18 Polyamide in multilayer film - PPS 2015
Moisture sensitivity of PA6
Permeability:
• dry: 20 cm3/(m2dbar)
• at 85 % RH: 31 cm3/(m2dbar)
values for 50 µm film thickness
![Page 19: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/19.jpg)
Page 19
Consequences for packaging
moisture insidepackaging
PEPA
PE = 100 µmPA = 20 µm
PA = outside
OTR = 16 ml/(m2day) OTR = 35 ml/(m2day)
moisture outsidepackaging
![Page 20: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/20.jpg)
Page 20
Processing
![Page 21: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/21.jpg)
Page 21
Moisture
![Page 22: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/22.jpg)
Page 22
Temperature
![Page 23: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/23.jpg)
Page 23
Double trouble?
![Page 24: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/24.jpg)
Page 24 Polyamide in multilayer film - PPS 2015
Melt stability
• polyamide is a condensation polymer
• when dry → polymerization• when wet → hydrolysis
![Page 25: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/25.jpg)
Page 25 Polyamide in multilayer film - PPS 2015
Melt stability
• reactivity depends on:- moisture content
- residence time
- temperature
- end groups
![Page 26: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/26.jpg)
Page 26 Polyamide in multilayer film - PPS 2015
Extrusion of PA6 – dry (<0.02 % H2O)
residence time
mo
lecu
lar
weig
ht
PA6 = high viscous polymer
![Page 27: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/27.jpg)
Page 27 Polyamide in multilayer film - PPS 2015
Extrusion of PA6 - wet (> 0.1 % H2O)
residence timemo
lecu
lar
weig
ht
PA6 = high viscous polymer
![Page 28: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/28.jpg)
Page 28 Polyamide in multilayer film - PPS 2015
Influence processing temperature of dry PA6
lownormal
residence timemo
lecu
lar
weig
ht
PA6 = high viscous polymer
![Page 29: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/29.jpg)
Page 29 Polyamide in multilayer film - PPS 2015
Moisture during film processing
Too much moisture results in:
• bubbles in the film
• bubble breaks
• hydrolitic degradation
• feeding problems
![Page 30: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/30.jpg)
Page 30 Polyamide in multilayer film - PPS 2015
How to deal with moisture
• resin is supplied dry and ready-to-use
• avoid moisture absorption
• maximum allowable moisture content 0.1
%
![Page 31: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/31.jpg)
Page 31
Bubble instability
![Page 32: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/32.jpg)
Page 32 Polyamide in multilayer film - PPS 2015
Bubble instability during processing
Possible causes (PA-related):
• viscosity too low- wrong grade selection- too high temperature- too high moisture content
![Page 33: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/33.jpg)
Page 33 Polyamide in multilayer film - PPS 2015
Process temperature
Polyamides have a sharp crystalline melting point
Recommendations:
• melt temperature:- PA6.66 ~ 225 °C- PA6 ~ 240 °C- PA66 ~ 270 °C
• apply a flat temperature or reversed temperature profile
• avoid adiabatic extrusion
![Page 34: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/34.jpg)
Page 34 Polyamide in multilayer film - PPS 2015
Example temperature control for PA6
1 2 3 4 Tpol230
250
270
290set actual
barrel zone
tem
pera
ture
[°C
]
1 2 3 4230
250
270
290set actual
barrel zone
tem
pera
ture
[°C
]
flat temperature profile reversed temperature profile
![Page 35: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/35.jpg)
Page 35 Polyamide in multilayer film - PPS 2015
Polyamide film properties
• films are hardly oriented• films are transparent• influence of moisture:
- when dry: high oxygen barrier high modulus
- when conditioned good oxygen barrier flexible postcrystallization possible
![Page 36: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/36.jpg)
Page 36
Applications
![Page 37: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/37.jpg)
Page 37 Polyamide in multilayer film - PPS 2015
Applications with polyamide - food
• meat• cheese• fish• milk• vegetables &
fruits• coffee
![Page 38: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/38.jpg)
Page 38 Polyamide in multilayer film - PPS 2015
Applications with polyamide – non food
• agricultural• medical• industrial
![Page 39: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/39.jpg)
Page 39 Polyamide in multilayer film - PPS 2015
Conclusions
• polyamide is a versatile polymer
• polyamide is easy to process
• polyamide has excellent mechanical
properties
• polyamide has good oxygen barrier
properties
![Page 40: Prejudices about polyamide for multilayer films](https://reader038.fdocuments.us/reader038/viewer/2022102816/55ba8cd0bb61eb3e0a8b46ea/html5/thumbnails/40.jpg)
Page 40
Email: [email protected]
Tel.: +31 651109899
Internet: www.extrusionist.com
Thank you foryour attention