Thursday, March 16, 2017

Material Comparison - PVC & PTFE

PTFE's significant chemical, temperature, moisture, and electrical resistances make it an ideal material whenever products, tools, and components need to be durable and reliable in even the most strenuous applications. On top of this, PTFE coated wire boasts unique low-temperature durability and fire resistance that make it a good choice for a constantly growing list of products, components, and applications.

PVC cables are manufactured at a much lower cost because they don’t have to meet the high temperature rating that PTFE cables do. PVC stands for Polyvinyl Chloride which is a compound engineered to be used in electronics and other indoor applications.

PVC electronic cables meet a 105°C temperature rating in 300 or 600 volts. They’re manufactured with flexible copper strands and PVC insulation on the inner conductors. They sometimes come with an aluminum overall foil shield and a tinned copper drain wire.

Now that you know the construction of a PVC cable you’ll probably understand why a PTFE cable is much more expensive. PTFE compound is used to manufacture a 200°C temperature material to cover the copper conductors. The engineering involved in creating a 200°C cable is much more involved than the process of creating a 105°C cable.

Property Name Units   ABS/PVC Alloy    PTFE Filled
Specific Heat Capacity BTU/lb-°F 0.382
Shear Modulus ksi
Compressive Yield Strength psi 3050 5710
Poisson's Ratio
Dielectric Constant 3.3 3.7
Dielectric Strength kV/in 508 467
Elongation at Break % 100 9.4
Flexural Yield Strength psi 7030 9820
Modulus of Elasticity ksi 319 348
Hardness, Rockwell R 88 110
Tensile Strength, Ultimate psi 4030 6580
Tensile Strength, Yield psi 5420 8270
Electrical Resistivity ohm-cm 1.00e+14 3.00e+15
Density lb/in³ 0.0423 0.0531
Max Service Temperature, Air °F 170 212
Thermal Conductivity BTU-in/hr-ft²-°F 1.87 1.67
Fracture Toughness ksi-in½

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