p84® polyimide fibres · p84® fibre characteristics | 3 p84® fibre characteristics the shown...

P84® Polyimide FibresProperties, Technical Data and Product Range

P84® Fibre Characteristics

Chemical Structure

Cross Section of P84® Fibres

2 | P84® Fibre Characteristics

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.

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.

P84® Fibre Characteristics | 3


The shown values together with the shape of the tension/elongation curve (see diagram) demonstrate that P84® is a typical textile fibre.

PropertiesUnits Units


Tenacity (dry)ElongationShrinkage (@240 °C, 15 min.)DensityLimiting Oxygen Index (LOI)Glass Transition Temp. (Tg)Moisture Gain at 20 °C (60 % rel. hum.)

38 cN/tex

30 %

< 3 %

1.41 g/cm3

38 %

315 °C

3 %

4,3 g/den

88 lb/ft3

599 °F

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 Shrinkage Characteristics

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.

P84® Fibre Shrinkage CharacteristicsTemperature [°C]

Shrinkage [%]6050403020100

250 260 270 280 290 300 310 320 330 340 350

▬ P84®; Test Duration: 30 min

P84® Stress/ Elongation Behaviour

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.

Stress/Elongation Behaviour Elongation [%]

Stress [cN/tex]4035302520151050

0 5 10 15 20 25 30

▬ Fibre titer: 2,2 dtex


Specific Surface Area

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®.

Specific Surface of Different Fibre Materials as Function of the Fibre FinenessFibre Titer [dtex]

Surface Area [m2/kg]600550500450400350300250200150100500

4 3 2 1 0

▬ P84® ▬ Procon™/Trilobal ▬ m-aramide ▬ PPS

P84® Fibre Moisture Gain at 20 °C

At standard conditions of 20 °C (68 °F) and 60 % relative humidity, the moisture gain of P84® fibres is 3 %.

Moisture Content [%] Relative Humidity [%]

P84® Fibre Moisture Gain at 20 °C

543210

0 10 20 30 40 50 60 70 80

▬ P84®; 20 °C, 60 % relative Humidity


Short Term Temperature Stability of P84®


Short Term Temperature Stability of P84® Temperature [°C]

Weight [%]

100

75

50

25

00 100 200 300 400 500 600

▬ 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.

Service Temperatures

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.

°C

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)

P84 PTFE

m-aramidePPS

PAN, PET

Max. Service Temperatures of Different Fibre Materials


P84® Fibre Isothermal Weight Loss

Differential Scanning Calorimetry (DSC) - Diagram of P84® in Air

Differential Scanning Calorimetry (DSC) - Diagram of P84® in Air Temperature [°C]

Endothermic Heat Flow [mW]2520151050

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.

Loss of waterOnset X = 349,945 °COnset Y = 20,0779 mW

Tg

P84® Fibre Isothermal Weight Loss Time [min]

Weight [%]

100

75

50

25

00 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.

400 °C

450 °C

500 °C

600 °C

300 °C / 350 °C



Electric Charge of P84® Fibres

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.

200150100500-50

25 30 35 40 45 50

Length[mm]Charge Intensity [pC/m]

Electric Charge of P84® Fibres

▬ before exposing ▬ after exposing

Thermal Conductivity

0,0040,00350,0030,00250,0020,00150,0010,00050

0 50 100 150 200 250 300 350 400 450

T[K]λ [W/(mK)]

Thermal Conductivity

▬ P84®, random card fleece ▬ Polyester, PP

The very low thermal conductivity of P84® fibres is used to design fleece constructions for insulating cryogenic processes.


Chemical Properties of P84®

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.

Chemical Properties of P84®

Concentration [%]

Temp. [°C/°F]

Time [hrs.]

Effect on tenacity

ChemicalsSulphuric 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

no = 0 to 15 % Loss in tenacity, minimal = 16 to 30 % Loss in tenacity

Oxidative Aging Loss of Tensile Strength of Needle Felts due to Oxidative AgingTime [days]

Tensile Strength [%]140120100806040200

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.



Hydrolysis Stability Hydrolysis Stability of Filter Fabrics @ 50 vol% Moisture, 170 °C Duration [days]

Tensile Strength [N]1000900800700600500400300200100

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 [%]

PTFEPPSP84®m-aramidePETPA

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.

95

40

38

28

22

22


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

100

75

50

25

0

▬ 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).

NOx

15

NOx NOx

4

NOx

25

NOx

15

HCN

93

HCN

82

HCN

73

HCN

123

HCN

28

Toxic Emissions Toxic Emissions acc. to ATS 1000.001 or BSS 7239 Emission [ppm]

COHCIHFSO2

NO2

HCN0 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.

3500

500

200

100

100

150

1

0

0

0

3

1

Chemicals

Evonik Fibres GmbH Gewerbepark 4 4861 Schörfling Austriaphone +43 7672 701-2891 fax +43 7672 968622 www. P84.com

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 respon-sibility 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 techno-logical 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 recom-mendation, 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.

p84® polyimide fibres · p84® fibre characteristics | 3 p84® fibre characteristics the shown...

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