On External Sheaths of Coaxial Radio-Frequency Cables of PJSC Odeskabel

Application of two main sheath types polyethylene (PE) and polyvinyl chloride (PVC) is determined by the cable operating conditions.

Cable types are applied depending on ambient conditions. In case of insolation, temperature gradients, moisture, etc., high-density polyethylene sheath is used while the low-density polyethylene sheath is used when laying cables underground.

High-density polyethylene is wear resistant and ensures better protection against mechanical effects. The PE sheath, as compared to PVC sheath, has a wider range of working temperatures and is less susceptible to abrupt temperature changes. PE sheaths absorb water dozens of time less than the PVC sheaths.

PVC sheath cables are used indoors, usually they are white (other colour is possible) to make more presentable appearance of the product.

At normal and high temperatures the PVC compound ensures better flexibility of the cable than polyethylene and makes it easier to fit connectors.

To produce a low-quality cable, as a rule its done without indication of the manufacturer, the PVC compound made of recycled raw material is used.

Such cable has a high water absorption capacity, low resistance to ultraviolet rays and low strength.

It leads to a premature fatigue of the material and reduces mechanical strength of the sheath, unstable electrical parameters and destruction of the cable. Such cable has a very short service life.

Polyethylene of various grades (compounds) is applied when making r.f. cables intended for service under low ambient temperature or at abrupt temperature changes.

Special anti-oxidizing stabilizers delay PE oxidation at ambient conditions (thermal-oxidative reaction).

Stabilizers improve heat resistance of polyethylene. Additives which prevent effects of copper on the polyethylene are used in some PE compounds.

To make PR compounds light resistant to ultraviolet solar irradiation, carbon black (soot) is added.

Resistance to fracturing and multiple bending at below zero temperature are imparted to PE compounds by rubbers.

Special flame-retarding additives are applied to make PE self-damping.

Knowledge of processing techniques and available tools make it possible to fix connectors quickly and in a quality manner, and install coaxial cables with PE sheaths.

The PJSC Odeskabel manufactures coaxial cables which are permanently used in various climate conditions, including in tropical areas.

Table 1

Properties of polyethylene and PVC compound used in coaxial cables of PJSC Odeskabel

ParameterPVCPE
Maximum working temperature, 7085
Minimum working temperature, -40-55
Water absorption during 24 hours, %0,35-0,40< 0,015

Thus, selection of the external sheathing of a coaxial cable depends on the operating requirements.