GenNex® PP25 polypropylene primary insulation is a thermoplastic flame retardant primary insulation designed to perform in combination with fluorinated ethylene propylene (FEP) insulated pairs in a category style communication cable. The polypropylene flame retardant insulation serves to lower the cost of the final cable without impacting flame performance.

KEY FEATURES

• High flame retardancy
• Excellent Electrical properties
• Good Processibility

PHYSICAL PROPERTIES

Density: 1.45 g/cm³
Tensile: 2000 psi (typical)
Elongation: 200% (typical)
Melt Index: 4.0 g/10 min.
Viscosity: 600 Nm

ELECTRICAL PROPERTIES

Dielectric Constant (DC): 2.84
Dissipation Factor (DF): 5.0 x 10^‐4

COMBUSTION PROPERTIES

Limited Oxygen Index (LOI): 36%

Cone Calorimeter (ASTM E1354):

• Peak Heat Release (kW/m²) 153
• Total Heat Release (MJ/m²) 34
• Time to Flame Out (s) 555
• Total Smoke Release (m²/m²)  1519

SUGGESTED RUNNING CONDITIONS

Extruder L/D: 20:1 or 25:1
Comp. Ratio: 3.0:1
Screen Pack: 20 mesh or none
Screw Type: Single Flight metering, without mixing section
Feed Zone: 320ºF
Screw Cooling: 165ºF
Gradient Cooling:  recommended
Center Zone:330-340ºF
Die Cooling: Not Recommended
Gradient Cooling: Recommended
Head/Die: 360ºF

PROCESSING TECHNIQUES

The PP Primary material has been designed to process easily on standard extruders used in the production of wire and cable products. The material has been designed to process similar to standard Polyethylene or Polypropylene based materials. High compression screws without a mixing section are preferred. Melt Temperatures above 380ºF (195ºC) should be avoided. The material can be extruded at wall thicknesses of less than 10 mils with no issues.
Gradient cooling is recommended to maintain maximum elongation values after extrusion. The material is supplied as free flowing pellets, packaged in sealed foil lined boxes. Gendon recommends the material be dried prior to use in a standard desiccant style dryer for a minimum of 4 hours at 140ºF (60ºC) prior to use.