MATERIALS FOR CABLES

Cables for higher voltages (> 6 kV) need conductor and insulation screens made of semiconductive plastic. Without these semiconductive layers

• high electrical stresses may cause volatile electrical fields in the insulation and
• premature breaks can occur

A cable with a semiconductive screen protects the insulation layer from electric stress

Premix’s portfolio offers high-quality semiconductive PP compounds. The compounding lines of the latest state-of-the-art ensure stable product properties and materials free of impurities.

PRE-ELEC^® PP18220 and PP18920 are developed for semiconductive screens in Medium Voltage (MV) power cables.

These polypropylene compounds

• Match the flexural modulus of XLPE
• Have excellent carbon black dispersion and conductivity
• Provide benefits of PP

Cross-linked Polyethylene (XLPE) is a commonly used thermoplastic in medium-voltage cables, but it can be replaced with Premix's Polypropylene (PP)—based PRE-ELEC^® compounds.

Why PP instead of XLPE in power cables?

A jacket protects the cable from mechanical damage during and after installation. Being semiconductive, the jacket also removes the risk of charge buildup due to capacitance.

Why semiconductive jacket based on PE-HD?

• PE-HD provides the optimal balance of stiffness and abrasion resistance.
• PRE-ELEC^® PE 19935 has good environmental stress cracking resistance (ESCR).
  Measured according to IEC 60811-406 Method B: up to 5000 h (5/10 specimen no-break). No specimen break before 168 h (F0).

PRE-ELEC^® PE 19935 is an optimized compound for semiconductive jacketing in HV and EHV cables with good ESCR.

 

Traditionally, lead (Pb) is applied as the water barrier in HV sub-sea cables

• Lead is a heavy, expensive, and poisonous metal.
• EU is expected to potentially ban its usage by 2026, with a three-year transition period.
• There is a huge potential for cost savings for a cable manufacturer in getting rid of lead. The more cable can be placed into one reel, the fewer joints are needed, and the cable weighs less.

New cable designs use aluminum (Al), copper (Cu), or copper-nickel (CuNi) layers instead.

• CuNi is not soft and can have nicks and buckling when bent while reeling the cable.
• A reinforcing layer on top of CuNi is needed, and a semiconductive adhesive layer in between.

PRE-ELEC^® PE 18500 and PE 19739 are unique PE-based semiconductive adhesives, developed particularly for this purpose, possessing good adhesion to copper and aluminum.

Protection against electromagnetic interference (EMI) has traditionally been pursued with metals such as aluminum.

Novel material solutions also include EMI shields made of semiconductive plastics.

Benefits of electrically semiconductive plastics in EMI shielding:

• Protects sensitive electronic components from EMI
• Semiconductive plastics are lightweight and enable corrosion resistance
• Premix’s material solutions are isotropic semiconductive

PRE-ELEC^® PP18147 is a unique semiconductive thermoplastic compound for EMI shielding. Potential material solution for the aviation, automotive, and many other industries.