Choosing GRP rods may seem like a technical production issue. Yet, a poor decision can undermine the strength of the optical cable and moisture management. Standard GRP rods and water blocking GRP rods both protect fragile optical fibres. Only one adds additional protection from water migration along the cable core.
To avoid premature cable failures, you need to consider more than price. Learn how both GRP rods work, where they can be used and what to watch out for when ordering them.
What Role Does the GRP Rod Play in the Optical Fibre Cable?
GRP rod includes glass fibres glued together with a resin. In most cases, it is placed in the centre of the optical fibre cable. There it manages the stretch, bend and buckling of the cable in the process of production, installation and operation.
The GRP rod is lightweight, non-metallic and electrically insulating. That’s why it is ideal for use in all-dielectric cable constructions. India’s Telecommunication Engineering Centre also requires FRP strength members to provide strength, flexibility and anti-buckling performance. Its tests cover tensile strength, bending, thermal expansion, water absorption and delamination.
Standard GRP Rod: Strong but Not Water Blocker
Standard GRP rod serves primarily as mechanical protection for optical cables. It manages fibre tension while pulling and heating the cable. Also, it ensures good dimensional stability without the weight of a metallic strength member.
However, a standard GRP rod cannot prevent the movement of water in the gaps inside the optical cable. It is necessary to include water blocking yarn, tape, gel or flooding compound to ensure proper moisture protection. This material suits indoor cables, dry routes, and cable designs that use proven moisture barriers.
Water Blocking GRP Rod: Extra Moisture Protection
Water blocking GRP rod integrates a GRP rod with water swellable coating. In case of moisture entry, it expands and seals any gaps nearby. Thus, it prevents water migration along the optical cable.
Reputable Water Blocking GRP Rod Manufacturers in India should be able to control rod diameter, coating thickness and surface quality. Moreover, the manufacturer should present test data for tensile strength, swelling time, swelling height and compatibility of materials.
The material may allow reducing or even eliminating the use of additional water blocking components in some cable designs. Thus, it allows using cleaner and thinner cable designs free of gel. Nevertheless, it is necessary to test the finished optical cable due to the individual character of each element.
Which Rod Provides Better Cable Protection?
The water blocking GRP rod provides better overall protection in wet ducts, tunnels, buried cables and flood-prone routes. According to the recommendations of ITU, the presence of water inside the optical cable core reduces the strength of fibre and shortens its service life.
The standard GRP rod can remain a reasonable and cost-effective solution for dry routes. Also, it suits the optical cable with reliable water blocking components.
Prior to ordering, it is important to request the batch records, test reports and dimensional tolerance from Water Blocking GRP Rod Manufacturers in India.
Get Reliable GRP Rods from Polyrod
The choice of a suitable rod depends on the design of the optical cable and installation route. Polyrod is among the reputable Water Blocking GRP Rod Manufacturers in India, producing standard, flat and water-swellable rods made of FRP and GRP. Feel free to contact Polyrod and discuss your requirements for optical cable.
FAQs:
Can standard GRP rod prevent the water ingress?
No, it needs additional water blocking yarn, tape, gel or another material.
Is it possible to use water blocking GRP rod as replacement for all moisture barriers?
It is not always possible. It depends on cable design and required test results.
Where should manufacturers use water blocking GRP rods?
It suits buried cables, wet ducts, tunnels and other moisture-prone routes.