P84 Fibre Technical Brochure

P84® Polyimide Fibres
Properties, Technical Data and Product Range
P84® Fibre Characteristics
Chemical Structure
The P84® fibre is a polyimide based fibre with a typical textile character.
Polyimides are known to be used in a wide range of operating temperatures
starting from cryogenic applications and ending with high temperature
applications at the limits of polymer based materials.
The thermal stability is based on the aromatic backbone of the polymer.
The fibres do not melt. Despite their halogen free structure they exhibit a
high LOI of 38 %, which means the P84 fibres are classified as non flammable.
P84® fibres have a rather unique cross section offering the highest specific
surface of all available standard textile fibres.
Cross Section
of P84® Fibres
The unique multilobal cross section offers up to 90 % more surface area
compared to conventional round fibres and is the key advantage of P84®.
This increased surface area results in the highest filtration efficiency of
conventional fibres, even for sub micron particles.
The fibres meet the requirements of all common textile processing steps.
Besides standard grades, micro denierfibres are part of the production range.
2 | P84® Fibre Characteristics
Product Range
P84® fibres are available as staple fibres and multifilament yarn.
Staple Fibre
Available Types: 0.6, 1.0, 1.7, 2.2, 3.3, 5.5 and 8.0 dtex
Cut Lengths (Standards): 53, 60, 80 mm
Special Cut Lengths: 2,5-120 mm
Bales: 150 kg and 200 kg
Colour: natural golden yellow or spundyed
Filament Yarn
Available Type: 1060 dtex, 480 single threads
Twist: 80 t/m
Packaging: 12 cones, 3,5 kg each
Colour: natural golden yellow
Spundyed Fibres & Filaments available on request
Color: black, navy-blue, orange, brown olive, dark gold
P84® Fibre
Characteristics
P84® Fibre Characteristics
Units
Units
Tenacity (dry)
38 cN/tex
4,3 g/den
Elongation
30 %
Shrinkage (@240 °C, 15 min.)
<3%
Density
1.41 g/cm3
Limiting Oxygen Index (LOI)
38 %
Glass Transition Temp. (Tg)
315 °C
Moisture Gain at 20 °C (60 % rel. hum.)
3%
Properties
88 lb/ft3
599 °F
The shown values together with the shape of the tension/elongation curve
(see diagram) demonstrate that P84® is a typical textile fibre.
P84® Fibre Characteristics | 3
P84® Fibre Characteristics
P84® Stress/
Elongation
Behaviour
Stress/Elongation Behaviour
Elongation [%]
Stress [cN/tex]
40
35
30
25
20
15
10
5
0
0
5
10
15
20
25
30
▬ Fibre titer: 2,2 dtex
As P84® fibres show a typical textile character the fibre can be processed
on standard carding and needling equipment.
According to the data, which show a low modulus and a relatively high
elongation, P84® is very well suited for textile applications and can be
processed using standard textile equipment.
The irregular lobed cross section and the crimp are responsible for the
bulkiness and the volume of the fibre.
P84® Fibre Shrinkage
Characteristics
P84® Fibre Shrinkage Characteristics
Temperature [°C]
Shrinkage [%]
60
50
40
30
20
10
0
250 260 270 280 290 300 310 320 330 340 350
▬ P84®; Test Duration: 30 min
During the manufacturing process, the fibres are stretched and the polymer
molecules are getting oriented to a certain extent. When exposing the fibres
to temperatures near the glass transition temperatures, a reorientation of the
molecules takes place and the fibres shrink. The diagram shows the significant
increase of the shrinkage after 30 minutes exposure at 315 °C (599 °F) and
beyond.
4 | P84® Fibre Characteristics
Specific
Surface Area
Specific Surface of Different Fibre Materials as Function of the Fibre Fineness
Fibre Titer [dtex]
Surface Area [m /kg]
2
600
550
500
450
400
350
300
250
200
150
100
50
0
4
▬ P84®
▬ Procon™/Trilobal
3
▬ m-aramide
2
1
0
▬ PPS
The large surface area primarily depends on the cross section and the fibre
titer (fineness).
All other fibres with same titer do not meet the specific surface area values
of P84®.
P84® Fibre
Moisture Gain
at 20 °C
P84® Fibre Moisture Gain at 20 °C
Relative Humidity [%]
Moisture Content [%]
5
4
3
2
1
0
0
10
20
30
40
50
60
70
80
▬ P84®; 20 °C, 60 % relative Humidity
At standard conditions of 20 °C (68 °F) and 60 % relative humidity, the
moisture gain of P84® fibres is 3 %.
P84® Fibre Characteristics | 5
P84® Fibre Characteristics
Service
Temperatures
Max. Service Temperatures
of Different Fibre Materials
N
PA
°C
, PE
T
S
PPide
m
ra
m
-a
P84
PTF
E
PAN, PET (125 °C, 257 °F)
PPS (200 °C, 392 °F)
m-aramide (210 °C, 410 °F)
P84 (260 °C, 500 °F)
PTFE (275 °C, 527 °F)
The acceptable average temperature depends on the environment and can be significantly lower
than the maximum service temperature.
The aromatic backbone ensures temperature stability over a wide range
of operating conditions. The peak temperature for the P84® fibre is limited
to 260 °C. This is well below the glass transition temperature of 315 °C.
Chemical decomposition starts beyond 450 °C without formation of
reasonable amounts of harmful substances.
The acceptable average temperature in the actual application is depending
on the composition of the environment and the expected service life.
Short Term
Temperature
Stability of P84®
Short Term Temperature Stability of P84®
Temperature [°C]
Weight [%]
100
75
50
25
0
0
100
200
300
400
500
600
▬ P84® *Medium: Air, Heating Rate: 20 °C/min
When exposed to high temperatures, P84® degrades the same way as
many other organic polymers, leaving a carbon structure. However, the
decomposition temperature is extremely high, as shown in the diagram.
6 | P84® Fibre Characteristics
P84® Fibre Isothermal
Weight Loss
P84® Fibre Isothermal Weight Loss
Time [min]
Weight [%]
100
300 °C / 350 °C
400 °C
75
450 °C
50
500 °C
25
0
600 °C
0
50
100
150
200
250
300
▬ P84®
The weight loss of P84® is recorded versus time at different temperatures.
Up to a temperature of 350 °C (662 °F) the weight loss is below 3 % and
corresponds to the moisture content of the fibre.
Differential Scanning
Calorimetry (DSC) Diagram of P84® in Air
Differential Scanning Calorimetry (DSC) - Diagram of P84® in Air
Temperature [°C]
Endothermic Heat Flow [mW]
25
Loss of water
Tg
20
Onset X = 349,945 °C
Onset Y = 20,0779 mW
15
10
5
0
50
100
150
200
250
300
350
400
450
500
▬ Fibre titre: 2,2 dtex ▬ Tg
This diagram shows, whether a material consumes or generates thermal
energy during a defined temperature program. Especially changes of the
structure and melting temperatures can be detected by using this method.
P84® has no peaks indicating crystalline regions or melting behaviour, only
a glass transition temperature is observed.
P84® Fibre Characteristics | 7
P84® Fibre Characteristics
Thermal
Conductivity
Thermal Conductivity
T[K]
λ [W/(mK)]
0,004
0,0035
0,003
0,0025
0,002
0,0015
0,001
0,0005
0
0
50
100
150
200
250
300
350
400
450
▬ P84®, random card fleece ▬ Polyester, PP
The very low thermal conductivity of P84® fibres is used to design fleece
constructions for insulating cryogenic processes.
Electric Charge
of P84® Fibres
Electric Charge of P84® Fibres
Length[mm]
Charge Intensity [pC/m]
200
150
100
50
0
-50
25
30
35
40
45
50
▬ before exposing ▬ after exposing
The diagram schows the electric charge along the length of a P84® fibre
before and after exposing to an electric field using a corona charge
of 20 kV.
All fibres do have either positive or negative charges due to functional groups
of the polymer and electrostatic excess charges.
8 | P84® Fibre Characteristics
Chemical Properties
of P84®
Chemical Properties of P84®
Concentration
[%]
Temp.
[°C/°F]
Time
[hrs.]
Effect on
tenacity
Sulphuric acid
10
20/68
100
no
Nitric acid
10
20/68
100
no
Hydrochloric acid
20
50/122
24
minimal
Hydrobromic acid
37
20/68
100
no
Hydrofluoric acid
40
20/68
100
no
Acetone
100
20/68
1000
no
Benzene
100
20/68
1000
no
Perchloroethylene
100
70/158
168
no
Chemicals
no = 0 to 15 % Loss in tenacity, minimal = 16 to 30 % Loss in tenacity
P84® provides good chemical stability to all common solvents, such as
alcohols, ketones, chlorinated hydrocarbons and a wide range of other
chemicals. It also offers high resistance to fats, oil and fuel. In addition,
P84® fibres have a proven record of good resistance in a broad range of
the pH-scale.
Oxidative Aging
Loss of Tensile Strength of Needle Felts due to Oxidative Aging
Time [days]
Tensile Strength [%]
140
120
100
80
60
40
20
0
0
50
100
150
200
250
300
350
400
▬ P84® ▬ m-aramide
Fibres exposed to air at high temperatures are deteriorated by oxygen. The
experimental results shown in the chart were carried out at 210 °C (410 °F)
and show superior performance of P84® compared to m-aramides.
P84® Fibre Characteristics | 9
P84® Fibre Characteristics
Hydrolysis Stability
Hydrolysis Stability of Filter Fabrics @ 50 vol% Moisture, 170 °C
Duration [days]
Tensile Strength [N]
1000
900
800
700
600
500
400
300
200
100
0
10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160
▬ P84® ▬ m-aramide ▬ PPS
Even under extremely high moisture contents, P84® outperforms many of
its competitors, being available for high temperature filtration applications.
Limiting Oxygen
Index (LOI) of Fibres
Limiting Oxygen Index (LOI) of Fibres
O2 [%]
PTFE
95
PPS
40
P84®
38
m-aramide
28
PET
22
PA
22
0
20
40
60
80
100
▬ PTFE ▬ PPS ▬ P84® ▬ m-aramide ▬ PET ▬ PA; according to ASTM D7438-08e1
The LOI indicates the level of oxygen needed to keep the material burning
after ignition.
P84® is classified as non flammable in atmospheric conditions.
10 | P84® Fibre Characteristics
Emission of Toxic
Gases during
Degradation
Emission of Toxic Gases during the Degradation of Fibres
m-aramide
wool
p-aramide
PAN
P84®
Emission [ppm]
125
123
100
93
82
75
73
50
25
0
NOx HCN
28
25
15
15
4
NOx HCN
NOx HCN
NOx HCN
NOx HCN
▬ m-aramide ▬ wool ▬ p-aramide ▬ PAN ▬ P84®
Source: "Toxic Products from Burning Textiles". Shirley Institute Manchester
Gas volume and gas composition are strongly depending on conditions like
excess or shortage of oxygen. Under the chosen conditions, P84® fibres
show the lowest generation of toxic HCN (cyanic acid).
Toxic Emissions
Toxic Emissions acc. to ATS 1000.001 or BSS 7239
Emission [ppm]
Chemicals
3500
CO
1
500
HCI
0
200
HF
0
100
SO2
0
100
NO2
3
150
HCN
1
0
100
200
300
400
500
▬ Emission limit ▬ P84® fibre
According to ATS 1000.001 which limits the toxic emissions for aircraft
interior, P84® shows excellent performance.
P84® Fibre Characteristics | 11
Legal References
This information and all further technical advice is
based on our present knowledge and experience.
However, it implies no liability or other legal responsibility on our part, including with regard to existing
third party intellectual property rights, especially
patent rights. In particular, no warranty, whether
express or implied, or guarantee of product properties
in the legal sense is intended or implied. We reserve
the right to make any changes according to technological progress or further developments.
The customer is not released from the obligation to
conduct careful inspection and testing of incoming
goods. Performance of the product described herein
should be verified by testing, which should be
carried out only by qualitfied experts in the sole
responsibility of a customer. Reference to trade
names used by other companies is neither a recommendation, nor does it imply that similar products
could not be used.
P84 is a registered trademark of Evonik
Industries AG or one of its subsidiaries.
Procon™ is the trademark of Toyobo Co., Ltd.
Evonik Fibres GmbH
Gewerbepark 4
4861 Schörfling
Austria
phone +43 7672 701-2891
fax +43 7672 968622
www.­P84.com