How do I find out whether an ÖLFLEX® cable is free of silicone and paint-wetting impairment substances (PWIS)?
In most cases, customers simply ask whether our cables and wires are free of silicone. What is actually being queried is whether the cables are free of "PWIS" (paint-wetting impairment substances), as silicone is not the only substance that can impede paint-coating.
The main PWIS are silicones, paraffins, special stearates, oils and greases. Cables and wires that contain such substances should not come into contact with any parts to be painted. The storage of such products in paint shops can also be problematic, even if there is no direct contact with unpainted work pieces; this is because substances like silicone in particular emit a lot of gas, which can settle on unpainted parts or even contaminate entire priming paint baths. The undesired consequence is that the paint fails to bond with the PWIS-contaminated sections of the work piece, resulting in the dreaded circular "craters" or "pinpricks" on the painted surface. Therefore, products containing silicone are strictly prohibited in such applications. In most cases, this restriction not only applies to cables and wires, but also to cable glands, connectors, protective conduits and other accessories.
Lapp Group can confirm that especially the ÖLFLEX® and UNITRONIC® cables which were tested in our own laboratory are free of PWIS. However, this confirmation only applies to the materials used during product manufacture. It does not cover the potential risk of subsequent contamination with paint-impeding substances when the products are handled during transport, storage and further processing.