1 Scope
This document gives specific requirements for polyethylene sheathing compounds, as
given in Table 1, for use in inner and outer sheathing of communication cables including fibre optic
cables.
It is expected to be read in conjunction with EN 50290‑2‑20, the product standards EN 50407 series, EN 50117 series, EN 60794 series and other applicable product standards.
Using raw material and type test data as outlined in this document, the raw material
supplier will have sufficient data to demonstrate compliance and warrant that the
material is suitable for the specified application.
There are several routes used for manufacture of polyethylene and as a consequence
a number of different types of polyethylene are defined as given in Table 1.
Table 1
—
Polyethylene materials (informative)
|
Abbreviation
|
Material type
|
Reactor process
|
Polymer structure
|
Maximum operating temperaturea
°C
|
|---|---|---|---|---|
| LDPEb | Low density polyethylene | High pressure/ temperature radical reaction | Long chain branched | +70 |
| LLDPE | Linear low density polyethylene | Low pressure/ temperature catalytic reaction | Significant short chain branching | +80 |
| MDPE | Medium density polyethylene | Low pressure/ temperature catalytic reaction | Short chain branched | +80 |
| HDPE | High density polyethylene | Low pressure/ temperature catalytic reaction | Limited short chain branching | +80 |