Cables Yarns & Tapes

Technology Overview

OASIS SAF® can be converted into spun yarns and nonwoven tapes for use as cable water blocking systems. Such systems are known as longitudinal water blocking or “Active” systems. They act by preventing water passage along the cable from a joint or point of damage to the outer sheathing.

Historically, Active System water blocking cables, such as telecoms cables, have used petrogel which acts by adhering to the components within the cable to close off all possible leakage pathways along the cable length. However, use of petrogel has many problems associated with messy application and difficulties with contamination of the gel.

Technology - Functionality

Cabling will require some form of water blocking system when used in external applications or when used in both external and internal applications without jointing. This includes cables for telecom, power and industrial applications. When cables become damaged, water begins to enter the cable at the point of damage. Such water ingress into the cable is immediately absorbed by the OASIS SAF® water blocking yarns and/or tape technology, resulting in rapid swelling and gel formation by the OASIS SAF®. This water blocking gel prevents any further ingress into the cable.

For copper cabling, water can ingress into the cable by diffusion through the outer polyethylene sheath. This is a high risk occurrence due to the fact that such cabling is typically laid under ground in areas likely to be damp and wet. The presence of water will degrade signal strength due to capacitance changes.

For Optical cabling, the presence of water ingress gives rise to risk of water freezing within the cable, generating excessive pressure on the optical components. This can result in high attenuation of the light transmission. Other problems can arise from corrosion by water of the metallic components within the cabling.

OASIS SAF® yarns & tapes offer the following performance characteristics:

• sufficient strength to withstand the stresses of the cable making process.
• resistant to cable operating conditions for the lifetime of the cable.
• fast swelling and gel formation rates on the commencement of water ingress into the cable.
• high gel expansion rate.
• high gel viscosity.
• long term stability of gel viscosity even at elevated temperatures.