From a practical point almost all cable manufacturers apply PVC (PolyVinyl Chloride) as their main insulation material. In our opinion this is the wrong choice. PVC is a basically a hard material. By adding a plasticizer, the composition obtains its soft properties and then is easy to be extruded as an external insulator around any kind of electrical conductor. But after a while the regular used plasticizers disappear to some extent, especially when the temperature is high (e.g. due to exposure to long wave infrared light of the sun). As a result, bending gets more difficult and puts extra mechanical stress on the internal conductor groups. This has its effect on the structural quality of the conductors. The disappearing plasticizers contain very environmental unfriendly chemicals including heavy metals.
As a side effect, PVC is not gas and liquid tight, it is a chemically non-closed structure which allows external pollution to penetrate and start chemical reaction with the internal conductors: Just watch the printing on a transparent PVC jacket. After a while the sharp printing will disappear and fade to coloured spots. The printing ink is absorbed by the PVC. Other chemicals will undergo the same effect.
And last but not least, PVC contains free chlorine that is able to react with the internal conductors (corrosion). As a result, black and even green copper conductors embedded in a more or less transparent or brown tanned insulation can be regularly seen. Reason enough for hi-fi freaks to buy another PVC insulated cable with the same disaster again after a year.
Our HULLIFLEX ® insulation material is in many ways better. It does not contain any plasticizers: This simply means that the flexibility remains equal in the long term and in any temperature zone. It is chemically completely inert and does not contain chlorine or any other halogens, so any kind of decay is impossible.
In contrast to PVC, HULLIFLEX ® furthermore is completely gas and liquid tight: Any chemical in contact with HULLIFLEX ® is unable to penetrate and reach the internal metal conductors. This has environmental as well as product protection reasons. HULLIFLEX ®’s hermetic properties safeguard the cable’s conductors against corrosive chemical activity and extend cable lifespan. In the long run this means that your cable will provide the same sonic quality as on the day you bought the product. A more safe investment in your sound and in the future of your family… I think.