Hulliflex®: PVC & Halogen Free Insulation

Our serious environmental considerations regarding our products find a world-wide appreciation, which for instance led to us having been awarded the Dutch GREEN AWARD.

In the start-up period around 1984, for the cheaper type of products our company has employed the internationally very well known PVC. With world-wide export to many countries in the mean time we have been facing pollution-problems of all kinds and intensities. Therefore the following considerations concerning the use of PVC (all cable manufacturers do use this material world-wide) and the application of another insulation material.

Although PVC has several advantages (easy to work with, cheap, flexible etc.), there are also multiple disadvantages to the use of PVC:
1. The plasticizer slowly disappears in time so the insulation will change in properties and get stiffer.
2. From a chemical viewpoint the plasticizer poses a very open window. All kinds of undesired chemicals can penetrate the PVC- jacket and start chemical reactions with the underlying conductors. This works out in colour-changes of the conductors in the first place. Somewhat later the sonic qualities are changing.
3. The chloride (the "C" in PVC) is not a pleasant element. When burned as waste it forms HCl (hydrochloric acid) in combination with water.
4. PVC is sensitive for penetration by contact dirt applied by hands during handling.
5. The surface cosmetics are not always constant due to minor temperature changes during the production extrusion process (ranges with 2 - 3 degree centigrade). So, material losses due to this effect in production are substantial.
6. PVC is an easy flammable product. In fire it produces toxic fumes.
7. The general move in Europe is to get away from PVC as a packing-material and also as an insulation material.

"But what other material could replace PVC?"

Already in 1989 this question was raised in our company. After intensive research and close co-operation with the chemical industry, HULLIFLEX ® was introduced in our cable brochure in 1990. At present we have upgraded to HULLIFLEX ® as the jacket insulation-material for the major part of our non-TEFLON cable product range.

The advantages of HULLIFLEX ® are obvious:
1. From a chemical viewpoint, to pollutants this insulation material is as closed as fort Knox. This will work out very positive in tropical conditions with high humidity and/or high pollution- levels. Also in typical sea-climate conditions (like close to shores with high humidity saturated with salt) a better protection is strictly necessary.
2. The flexibility does not change under the influence of ozone or ultraviolet light or penetration of other chemicals (see point 1).
3. The surface acceptance for-, or penetration by contact-dirt is extremely low.
4. The quality/durability curve is expanded by a factor 35 or more.
5. The mechanical strength is tripled compared to PVC.
6. The surface friction is lower and stable compared to PVC.
7. Compared to PVC, the dynamic mechanical damping is greatly improved compared
to PVC. This is especially important in car hi-fi applications where pulsating mechanical vibrations can damage the electrical conductors.
8. The thermal endurance is higher than that of PVC.
9. The basic white HULLIFLEX ® will just accept the air temperature and not the sum
of the air temperature and the radiation temperature. This will work out very positive in tropical climates.
10. The flexibility will not change with higher temperatures.
11. The surface is always very silky and smooth. Production problems with changing surface cosmetics from now on are finished.
12. Cable print problems or removable printing are finished.
13. The mechanical reinforcement of the total product is strongly improved. So the
mechanical load is taken away from the electrical conductors in critical situations.
14. And from the environmental point of view, HULLIFLEX ® is superior to PVC.

The negative aspects of HULLIFLEX ® are very limited:
1. In the beginning there is a somewhat stronger plastic smell than is the case with
PVC. This smell will disappear very soon.
2. The price is 4 x higher compared with PVC. Nevertheless we will not change the
price of our standard products because of the change from PVC to HULLIFLEX ®.
3. De-insulation is somewhat more difficult due to the improved mechanical properties.