Cable Compounds

Semi-conductive carbon black is commonly used for conductor shielding and isolation shielding in medium and high voltage cables. It is known for smoothing out peaks of the inhomogeneity of electricity, therefore ensuring an even distribution of the electric field between the external insulation and metallic screen.

Highlights:

• Very high pigment and additive loading levels possible as required (20-40 %)
• Extremely gentle wetting of the pigments thus avoiding agglomerations
• Excellent gentle dispersion and distribution of carbon black to obtain conductivity
• High throughput rates for maximum productivity
• Excellent feeding of high-volume ingredients such as carbon black
• Low specific energy input for low melt temperatures
• Maximum product quality

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HFFR (Halogen Free, Flame Retardant) cables have a lot of advantages: They are fire retardant, self-extinguishing with low smoke development. Degradation product is water. In the compounding process EVA, PP and PE polymers are combined with fillers (usually aluminum trihydroxide (ATH) or magnesium hydroxide (MDH)) which add the flame retardant properties.

Highlights:

• Because of its good mixing properties, the low shear introduction, the reproducibility of the process, product purity, and the great flexibility of the recipes, many producers in the cable industry rely on the continuous processing of the Coperion ZSK twin scew extruder.
• For high accuracy feeding of all ingredients Coperion K-Tron feeders are used.
• The ZSK twin screw extruder in ZSK Mv PLUS design together with ZS-B twin screw side feeders are able to process halogenfree flame-retardant compounds (HFFR) highly economically.

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PVC (Polyvinyl chloride) cables are known for their flame-retardant properties. Thanks to various plasticizers and additives they can also be made resistant to e.g. many chemicals which makes them durable and suitable for various applications, such as household appliances, assembly lines or communication technology equipment.

Highlights:

• Good infeed behavior even with poorly flowing powders and hot dryblend from fast hot mixer
• Low specific energy requirement
• Very uniform shearing, homogenization, and pelletizing of the product recipes
• Easy cleaning for fast product change in the case of different batch sizes
• Highest flexibility for product changes and machine modifications, resulting in a wide range of applications
• High reliability and proven machine technology

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XLPE cable compounds are made of  PE cross-linkable via peroxide. They are characterized by their hjgh purity, and equal distribution of the peroxide in the pellets. As a result they can be used for high to extra high voltage applications.  

Highlights:

• Reliable production of high-quality peroxide cross-linkable PE for both medium and high-voltage applications
• In the compounding step polymer is molten and highly filtrated
• Under water pelletizer is mandatory
• Peroxide for later crosslinking is added in silo (Post blending)
• Coperion has comprehensive process know-how to set up compounding and pelletizing systems that ensure highest purity and product quality

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Silane cable compounds are made in a grafting process (Sioplas). They have a higher heat-resistance than pure PE and are suitable for low to medium voltage applications. In addition, the process is flexible and thanks to its high extrusion rate it is known for being cost-effective.

Highlights:

• Silane grafted on PE and EVA, crosslinking in further processing with water
• Low amount of peroxide is required
• Melt filtration possible
• Strand pelletizing is possible depending on formulation
• Filling with ATH / MDH in the same or in a second step is state-of-the-art

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Cables insulated with fluoropolymers are non-flammable and highly resistant to even aggressive chemicals such as acids. Depending on the base polymer a high temperature resistance is given. The thermal conductivity can be adjusted by the incorporation of carbon black. Thus,fluorpolymers are typically used for heating cables.

Highlights:

• Special materials of construction for product touching parts
• Very high corrosion resistance 
• High process temperatures possible (up to 450 °C)

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TPE (Thermoplastic Elastomer) combines polymers with rubber as a result of which it has both thermoplastic and elastomeric properties. It is highly durable and allows for flexing without being damaged. Therefore, it is commonly used in robotics and automotive applications as well as in harsh environments.

Highlights:

• Reduced thermal stress on the raw materials
• Safe devolatilization
• Additivation as required

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