# Thermal resistivity of filler

The IEC 60287 does not list materials for filler but states: depending on the filler material and its compaction, the thermal resistivity is in the range 6 to 13 K.m/W for cables with extruded insulation, 10 K.m/W is suggested for fibrous polypropylene.

Following values are taken from IEC 60287-2-1 Ed.2.0 for insulation or jacket with following additions:

• The value for fibrous polyolefin copolymer (fPOC) is taken from the book 'Handbook of Polyolefins' by C. Vasile (2000)
• The value for fibrous polypropylene (fPP) is taken from Table 1 Thermal conductivity of various fibres (Hearle and Morton, 2008) whereas the IEC 60287-2-1 Ed.2.0 suggests a slightly higher value.
• The value for fibrous polyethylene (fPE) and polyvinyl chloride (fPVC) is considered to be twice the value used for insulation.
• The value for the tapes is an approximative mean value based on different sources
• The value for air is taken from engineeringtoolbox.com
• The value for other materials (Ot) is considered to be as suggested by the IEC 60287-2-1 Ed.2.0 for fibrous polypropylene.

Symbol
$\rho_f$
Unit
K.m/W
Related
Used in
$T_1$
$T_2$
Choices
MaterialValue
fPOC6.6
fPP9.0
fPE7.0
fPVC12.0
sPVC6.0
sPE3.5
PRod8.0
PTube12.0
OilD6.0
TY5.3
Jute6.0
tape6.0
Air38.2
Ot10.0