What is talcum powder?
Why use talcum for cables?

igu-blog-adm | 8. March 2021

When I hear the term talcum, I immediately think back to sports lessons at school. Gymnastics. Not my favourite discipline. I always found it exciting to rub my hands with this white powder. But that was pretty much all that fascinated me about this sport. But let’s get back to the topic. Talcum. What is talcum powder? And what role does talc play in cables?

What is talcum powder?

For that, let’s jump back to sport.

If you look more closely, the white powder in the gymnastics area is a mixture of chalk and talc. The added talcum powder keeps the hands smooth and gliding. Especially on apparatus like the high bar, gymnasts need a firmer grip, but at the same time the possibility to make gliding movements. It’s similar with cables, too.

Talcum consists of crushed talc. Talc, in turn, is a mineral consisting of magnesium silicate.  This can bind water and is therefore very versatile. Talc is a very soft material that is often better known as steatite or soapstone.

Why is talc used in cables?

Talc not only absorbs moisture, but also serves as a separating agent and lubricant. In the cable industry, for example, it separates the jacket and the cores from each other.

Similar to the sports sector, talcum reduces friction and helps the cores in the cable to last longer. The reason for this is that they can slide under the jacket or against each other in the longitudinal direction.

The plastic of the insulation is well separated from the jacket material during production. First the cores are stranded and then the liquid plastic of the jacket is injected around them. Without the talc, there is a risk that the heat of the jacket will soften the insulation surface and cause it to stick to the jacket. This then leads to poor durability in motion and also to poorer processing options.

The use of talc makes stripping much easier, because the jacket can be pulled off after the round cut.