Dissipation Factor of Plastic Materials Explained

Paul Martin from Omnexus, a SpecialChem company put together a comprehensive article on Dissipation Factor of Plastic Materials which includes Min Value (°C) & Max Value (°C) table. This may be quite useful when evaluation various plastic polymer material properties.

Plastics and Importance of DF

Dissipation factor (DF or tan δ) is the electrical property of plastics and other electrical insulating materials. It is defined as the reciprocal of the ratio between the insulating materials’ capacitive reactance to its resistance (Equivalent Series Resistance or ESR) at a specified frequency.

In other words, it is defined as a ratio between the permittivity and the conductivity of an electrical insulating material

The property is also referred as the tangent of the loss angle, loss tangent, tan delta, approx. power factor…

It measures the electrical energy absorbed and lost (power dissipation) when electrical current is applied to an insulating material. Most of the absorbed energy is dissipated as heat.

Dissipation factor indicates the inefficiency of material to hold energy or behave as an insulating material. The lower the dissipation factor, the more efficient is the insulator system. Most plastics have relatively lower dissipation factor at room temperature.

Dissipation Factor is a dimensionless measure and hence no units.

Applications include:

The low dissipation factors indicated high-quality, high performance electrical or electronic systems. It is important for plastic insulators in high-frequency applications such as radar equipment or microwave parts.

Low values mean better dielectric materials with less dielectric heating

The high dissipation factors are important for polymers that are to be heated in a radio frequency or microwave oven for welding or drying etc. Also, material used for high capacitance requires high dielectric constant and low dissipation factor.

Dissipation factor can also be used to assess the characteristics or quality of an insulating material in applications such as cable, terminations, joints etc. for moisture content, deterioration etc. However, here initial values of dissipation factor of tested material are important.

How to Calculate Dissipation Factor of an Insulator?

Dissipation factor is the tangent of the loss angle of the insulating material.

In an ideal capacitor without any dielectric losses, the insulation current is exactly 90° leading according to the applied voltage. As dielectric becomes less than 100% efficient, when the current wave begins to lag the voltage in direct proportion.

The dielectric phase angle, θ, is the angular difference in phase between the sinusoidal alternating potential difference applied to a dielectric and the component of the resulting current having the same period as the potential difference.

Essentially, this means that when an alternating current is applied across an insulating material, the resulting alternating current passing through it (no matter how small) will be at a different phase than the voltage.

The amount of current wave deviates from being 90° out of phase with voltage is defined as the dielectric loss angle (90°- θ). The tangent of this angle δ is known as the loss tangent or dissipation factor.

Phasor Diagram for tan δ Measurement The tan δ measured at a frequency ω and voltage V, is the ratio of the resistive (IR) and the capacitive (IC) currents according to:


Dissipation Factor Vs. Power Factor

The power factor of an insulator is defined as the ratio of power dissipated in watts to total charging volt-amperes or it is the cosine of the angle between the voltage applied and the current resulting i.e. the dielectric phase angle θ.

If the dissipation factor (tan δ) is very small – typically less than 10%, then the dissipation factor and the power factor differ in a negligible amount and can be assumed to have the same value.

Dielectric loss factor or loss factor of a material is an another frequently used term. It is the product of dielectric constant and the dissipation factor. It is related to the total loss of power occurring in plastics or any other insulating materials. Or how easily the material will heat up in a high frequency field.

Dissipation Factor of Plastics

Plastic materials are mostly exhibiting good insulation properties and thus some of them are used as a common dielectric materials for plastic organic film capacitors.

Standard Methods Used to Determine DF

The most generally used standard tests to calculate dissipation factor for plastics are ASTM D2520, ASTM D150 or IEC 60250 (of course there exist several other methods as well, but they are not discussed here).

The method includes:

A sample is placed between two metallic plates and capacitance is measured. A second run is measured without the specimen between the two electrodes. The ratio of the power dissipated in the test material to the power applied is dissipation factor:

Factors Influencing Dissipation Factor

Factors such as frequency, temperature, voltage, humidity, and weathering affect dissipation factor of plastics to varying degrees, depending on the level and duration of exposures.

Find commercial grades matching your electrical properties target using “Property Search – Dissipation Factor filter in Omnexus Plastics Database:

Dissipation Factor (DF) Values of Several Plastics

Polymer NameMin Value (°C)Max Value (°C)
ABS – Acrylonitrile Butadiene Styrene50190
ABS Flame Retardant7090
ABS High Heat20350
ABS High Impact20350
ABS/PC Blend – Acrylonitrile Butadiene Styrene/Polycarbonate Blend70200
ABS/PC Blend 20% Glass Fiber2090
ABS/PC Flame Retardant4070
Amorphous TPI Blend, Ultra-high heat, Chemical Resistant (Standard Flow)0.0010.001
ASA – Acrylonitrile Styrene Acrylate90340
ASA/PC Blend – Acrylonitrile Styrene Acrylate/Polycarbonate Blend20190
ASA/PC Flame Retardant110170
CA – Cellulose Acetate1001000
CAB – Cellulose Acetate Butyrate100400
CP – Cellulose Proprionate60300
CPVC – Chlorinated Polyvinyl Chloride100200
ECTFE – Ethylene Chlorotrifluoroethylene130170
ETFE – Ethylene Tetrafluoroethylene6100
EVA – Ethylene Vinyl Acetate1301000
EVOH – Ethylene Vinyl Alcohol18002200
FEP – Fluorinated Ethylene Propylene77
HDPE – High Density Polyethylene320
HIPS – High Impact Polystyrene420
HIPS Flame Retardant V0550
Ionomer (Ethylene-Methyl Acrylate Copolymer)2020
LCP – Liquid Crystal Polymer4040
LCP Glass Fiber-reinforced60300
LCP Mineral-filled70280
LDPE – Low Density Polyethylene34
MABS – Transparent Acrylonitrile Butadiene Styrene2.83
PA 11 – (Polyamide 11) 30% Glass fiber reinforced0.030.03
PA 11, Conductive0.050.25
PA 11, Flexible0.050.25
PA 11, Rigid0.050.25
PA 12 (Polyamide 12), Conductive0.050.25
PA 12, Fiber-reinforced0.050.25
PA 12, Flexible0.050.25
PA 12, Glass Filled0.050.25
PA 12, Rigid0.050.25
PA 46 – Polyamide 46190600
PA 46, 30% Glass Fiber2390
PA 6 – Polyamide 6100600
PA 6-10 – Polyamide 6-10400400
PA 66 – Polyamide 6-6100400
PA 66, 30% Glass Fiber1001500
PA 66, 30% Mineral filled2001500
PA 66, Impact Modified, 15-30% Glass Fiber130200
PA 66, Impact Modified1002000
Polyamide semi-aromatic33.1
PAI – Polyamide-Imide60710
PAI, 30% Glass Fiber220500
PAR – Polyarylate20200
PBT – Polybutylene Terephthalate10200
PBT, 30% Glass Fiber20120
PC (Polycarbonate) 20-40% Glass Fiber975
PC (Polycarbonate) 20-40% Glass Fiber Flame Retardant9100
PC – Polycarbonate, high heat69100
PC/PBT blend, Glass Filled100200
PCTFE – Polymonochlorotrifluoroethylene10250
PE – Polyethylene 30% Glass Fiber2080
PEEK – Polyetheretherketone3030
PEEK 30% Carbon Fiber-reinforced2932
PEEK 30% Glass Fiber-reinforced2020
PEI – Polyetherimide1325
PEI, 30% Glass Fiber-reinforced1553
PEI, Mineral Filled1015
PEKK (Polyetherketoneketone), Low Cristallinity Grade0.0040.004
PESU – Polyethersulfone10140
PESU 10-30% glass fiber70100
PET – Polyethylene Terephtalate20200
PET, 30% Glass Fiber-reinforced1201680
PET, 30/35% Glass Fiber-reinforced, Impact Modified1.51.5
PETG – Polyethylene Terephtalate Glycol20300
PE-UHMW – Polyethylene -Ultra High Molecular Weight22
PFA – Perfluoroalkoxy22
PI – Polyimide1850
PMMA – Polymethylmethacrylate/Acrylic200200
PMMA (Acrylic) High Heat400600
PMMA (Acrylic) Impact Modified300400
PMP – Polymethylpentene0.730
POM – Polyoxymethylene (Acetal)50110
POM (Acetal) Impact Modified50250
POM (Acetal) Low Friction2090
POM (Acetal) Mineral Filled1.51.6
PP – Polypropylene 10-20% Glass Fiber1020
PP, 10-40% Mineral Filled711
PP, 10-40% Talc Filled711
PP, 30-40% Glass Fiber-reinforced1020
PP (Polypropylene) Copolymer35
PP (Polypropylene) Homopolymer35
PP, Impact Modified35
PPA – Polyphthalamide270270
PPA, 33% Glass Fiber-reinforced – High Flow0.0140.016
PPA, 45% Glass Fiber-reinforced0.90.2
PPE – Polyphenylene Ether49
PPE, 30% Glass Fiber-reinforced1015
PPE, Flame Retardant731
PPS – Polyphenylene Sulfide430
PPS, 20-30% Glass Fiber-reinforced1032
PPS, 40% Glass Fiber-reinforced1320
PPS, Glass fiber & Mineral-filled70580
PPSU – Polyphenylene Sulfone1750
PS (Polystyrene) 30% glass fiber528
PS (Polystyrene) Crystal128
PS, High Heat128
PSU – Polysulfone864
PSU, 30% Glass finer-reinforced4060
PTFE – Polytetrafluoroethylene22
PTFE, 25% Glass Fiber-reinforced55
PVC, Plasticized4001600
PVC, Plasticized Filled4001600
PVC Rigid60200
PVDF – Polyvinylidene Fluoride2001700
SAN – Styrene Acrylonitrile70100
SAN, 20% Glass Fiber-reinforced10100
SMA – Styrene Maleic Anhydride4040
SMMA – Styrene Methyl Methacrylate400400
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