Washing test / Attenuation

There are plenty of rumors in circulation: 1) Fabrics with silver-lacquered copper threads are said to be especially robust. 2) Steel threads of fabrics would break easily. 3) Fabrics with exposed silver threads are said to be extremely damageable. Well, being the worldwide biggest supplier of shielding textiles, we know the answers. Now we are publishing the results of our fifth and latest washing test!

Washing and drying

We have washed all well-known fabrics 50 times. This time we used an eco- washing powder called “Neutral“ by „Sonett”. The washing time was 45 minutes with a gentle wash cycle at 30°C, and after this, a 45 minutes dryer cycle at 40°C. This drying cycle was used to simulate the normal usage of the fabrics as curtains, canopies or clothing.

Measuring method

To measure the attenuation, we opted for the measuring method according to ASTM D4935-10. This method provides a radial measurement (in all polarisation directions) which is very close to reality! In addition, the frequency range from 30 MHz to 4 GHz can be measured in a single step with the coaxial TEM measuring head.

Test result

The orange bar stands for the attenuation before washing. The numbers to the left indicate the attenuation in dB at 1 GHz. Each further bar stands for 5 wash cycles.



Rumor 1 is challenged by Wear and New-Daylite fabrics. Rumor 2 is challenged by Steel-Twin. Rumor 3 is challenged by Silver-Silk, Silver-Tulle, Silver-Twin and Silver-Jersey. Please keep in mind that despite the seemingly poor results, they do make sense in a practical situation, for example Perspective is hardly likely to be washed 50 times over it´s lifetime when used as net curtain or box-shaped canopy.

The most suitable fabrics for curtains/net curtains are Voile, Naturell, Silver-Tulle, Silver-Twin.  The best fabrics for canopies are Voile and Silver-Tulle. The most stable fabric for clothing is Silver-Jersey.

Tips

In the previous four washing tests we also used cheap washing powders, f.e. of Aldi which had very bad effects on the attenuation. It is therefore very important that the washing powder does not contain any enzymes and softeners.  „Basic- or neutral washing powders“ are suited best.  The best way is to hang out the washing dry. If you use a dryer keep the temperature low. The same counts for ironing (degree 1 and little steam).