Water blocking yarns

Fitco Yarns

These yarns are made of superabsorbent polymers and a combination of different polymers to obtain excellent water blocking.


Specialised fibres

Waterblocking yarns are specialised fibres used in the manufacture of cables and wires to prevent water ingress and maintain the integrity of the electrical or optical signal transmission. These yarns are typically made from highly water-absorbent materials, such as superabsorbent polymers (SAPs).

Protect the cable core

The primary purpose of waterblocking yarns is to protect the cable core from moisture damage, which can cause signal loss, degradation, or even complete failure. They are commonly used in underground, outdoor, or harsh environmental conditions where cables are exposed to water, moisture, or high humidity levels.

Barrier to stop water penetration

Waterblocking yarns work by absorbing and blocking the passage of water along the cable length. When exposed to moisture, the yarns swell and form a gel-like substance, which creates a barrier against further water penetration. This gel-like material not only prevents water from reaching the cable core but also helps to disperse any existing water, reducing the risk of damage.

Mechanical strength & support

In addition to their waterblocking properties, these yarns may also provide mechanical strength and support to the cable structure. They are often incorporated into the cable design as either fillers, binders, or waterblocking tapes, depending on the specific requirements of the cable construction.

Overall, waterblocking yarns play a crucial role in ensuring the long-term reliability and performance of cables, especially in environments prone to moisture or water exposure.


Swellable yarns are used to make cables water resistant:

  • Low, medium and high voltage cables
  • Data and telecom cables
  • Fiber optic cables

Other products


Fitco Fabrics

Fitco filtration fabric is made from polyamide (PA) and is specifically designed for filtration applications. Polyamide, also known as nylon, is a synthetic polymer that offers excellent strength, durability and resistance to abrasion, chemicals, and high temperatures.

Read more

Zargal PP

Fitco Strapping

PP extruded strap is the most economical of all strapping material due to its light weight and versatility. It is available in a wide range of sizes and colours.

Read more

Fitco Grass

Fitco Grass

Fitco Grass artificial grass yarns, also known as synthetic turf fibers, have various features that make them suitable for use in artificial grass installations. Today, Fitco Grass is n°1 in Europe for artificial sports grass yarns for padel, hockey and football.

Read more