Power Cable Semi-conductive Compound Wholesale Factory

HJ Polymer supplies semi-conductive shielding compounds that sit between the conductor and the insulation of power cables, controlling the electric field across the full voltage range from 1 kV distribution cable to 220 kV transmission cable. Our range covers conductor shield, insulation shield and bonded or strippable grades, supplied as pellets for extrusion on CCV, VC and Sioplas lines.

We are a Power Cable Semi-conductive Compound Wholesale Factory working directly with cable producers, compound distributors and EPC project teams. Our proposal is built from the working voltage class, insulation system, line speed and the acceptance criteria of the cable standard you build to.

What Semi-conductive Shielding Compounds Do in a Cable

The shielding layer is a thin extruded polymer layer with a continuous conductive carbon black network. Its job is to equalise the electric field, suppress partial discharge and protect the insulation from local stress concentration at the conductor surface and at the insulation screen.

• Conductor shield: extruded directly over the stranded conductor, smoothing the conductor surface and preventing voids at the metal–insulation interface.
• Insulation shield: extruded over the XLPE insulation, providing a strippable or bonded screen that carries leakage current to the metallic screen.
• Bonded interface: for MV and HV designs, the shield must bond firmly to the insulation without delamination, migration or protrusion.

Our Power Cable Shield Compound Range

We group our compounds by voltage class and by the position of the layer in the cable. Each grade is formulated for a specific extrusion behaviour, surface finish and interface requirement.

LV/MV Cable Shield Compound

For low-voltage distribution networks and medium-voltage cables up to 35 kV. High-purity conductive carbon black is dispersed to form a stable conductive network with volume resistivity typically below 100 Ω·cm. The formulation resists filler migration into the insulation layer, which protects insulation resistance over the cable lifetime.

MV Cable Conductor Shield Compound

Our largest family, covering 6–35 kV urban distribution, industrial park, wind, photovoltaic and rail transit cables. Grades are separated by interface behaviour and line condition: bonded insulation grade, easy-strippable grade, fast line speed grade, copper oxidation resistance grade and super clean grade. This lets us match the compound to your extruder output, crosshead design and stripping requirement rather than forcing one grade across the whole plant.

HV Cable Shield Compound

For XLPE cables at 110 kV and above. Carbon black distribution is tightly controlled to hold volume resistivity in the 10–100 Ω·cm range, with refined raw materials and controlled metal ion and particle contamination to suppress tip-induced breakdown and partial discharge. HJ0901 is our super clean and smooth grade for conductor and insulation shielding in high-voltage cable.

Critical Specifications We Work To

Shield compound performance is judged on a small set of measurable properties. We formulate and test against these values, and we confirm the target window with you before production.

• Volume resistivity: below 100 Ω·cm for LV/MV conductor shield; 10–100 Ω·cm for HV grades.
• Surface smoothness: controlled protrusion count and size, critical for HV partial discharge performance.
• Interface behaviour: bonded or strippable, with defined peel strength for the stripping method used on site.
• Cleanliness: low contamination level, controlled ash and metal ion content.
• Processing: melt flow and crosslinking behaviour matched to your line speed and cure conditions.
• Thermal stability: consistent extrusion over long runs without scorch or die build-up.

Application Fit Across Cable Types

Our compounds are used in cables for power transmission and distribution, construction and municipal networks, industrial automation and control cabling, telecommunications and 5G infrastructure, rail transit and transportation hubs, and photovoltaic, wind and energy storage systems. The common requirement across these applications is a stable electric field at the conductor and insulation interfaces.

For specialty constructions — flame-retardant sheaths, halogen-free designs, high-temperature or oil-resistant service — we review the compound selection against the cable specification and the operating environment before recommending a grade.

Manufacturing and Quality Control

HJ Polymer operates 13 dedicated production lines in a facility of more than 30,000 m², with automated process control systems for consistent output. Annual capacity is 62,000 tons of medium- and high-voltage grade material, and monthly capacity is 5,200 tons. Our products are halogen-free and compliant with RoHS and other environmental regulations.

Quality control follows a certified quality management system. Incoming raw materials, in-process compound and finished pellets are checked for resistivity, cleanliness, moisture and processing behaviour. Our products comply with UL, IEC, GB and other international standards, and we participate in national and industry standard development for cable shielding materials.

Customization and Technical Support

We provide customized formulations for specific cable designs, line conditions and regional standards. Customization can cover resistivity window, strippability, line speed, copper oxidation resistance, flame retardancy and colour. Our R&D team includes PhDs and senior engineers, and we operate a graduate workstation with Jiangsu University of Science and Technology.

Technical support covers grade selection, trial run planning, extrusion parameter guidance and troubleshooting on the line. Samples are available for evaluation before full production orders.

Information We Use to Configure Your Solution

To prepare a suitable compound recommendation and quotation, we need the following project inputs. The more precisely these are defined, the faster we can confirm the grade and supply plan.

• Cable voltage class and standard (IEC, GB, UL or other).
• Layer position: conductor shield, insulation shield or both.
• Insulation system and whether bonded or strippable interface is required.
• Extrusion line type (CCV, VC, Sioplas) and typical line speed.
• Target volume resistivity and surface smoothness requirements.
• Conductor material and any copper oxidation concern.
• Annual or project volume, delivery schedule and packaging preference.
• Any special environmental or flame-retardant requirements.

Packaging, Delivery and Serviceability

Compounds are supplied in moisture-protected packaging suitable for storage and transport. Shelf life is 9 months under recommended storage conditions. Delivery lead time for standard grades is typically one week, and we confirm the schedule for custom formulations at order review.

After-sales support is handled by a professional service team with a rapid response system. We provide documentation for incoming inspection and traceability, and we can arrange production facility visits for project qualification.

Frequently Asked Questions

What voltage classes do your shielding compounds cover?

We supply conductor and insulation shielding compounds for low-voltage cable (1 kV and below), medium-voltage cable (6–35 kV) and high-voltage cable (110 kV and above). The grade selection depends on the layer position, insulation system and line conditions.

Can you supply both conductor shield and insulation shield compounds?

Yes. Our range includes conductor shielding compounds, insulation shielding compounds and combined grades. For MV cables we offer bonded, easy-strippable, fast line speed, copper oxidation resistant and super clean grades so the compound matches the cable design and the stripping method.

Do you provide samples for evaluation?

Yes. We supply samples for trial extrusion and testing before full production orders. We recommend sharing the cable construction, line type and target specifications so we can select the most relevant grade for the trial.

What is your production capacity and lead time?

Annual capacity is 62,000 tons across 13 dedicated production lines, with monthly capacity of 5,200 tons. Standard grade lead time is typically one week; custom formulations are confirmed at order review.

Do your compounds comply with international standards?

Our products comply with UL, IEC, GB and other international standards, and are halogen-free and compliant with RoHS and other environmental regulations. We participate in national and industry standard development for cable shielding materials.

Can you customize a compound for our cable design?

Yes. We provide customized formulations for specific resistivity windows, strippability, line speed, copper oxidation resistance, flame retardancy and colour. Our R&D team includes PhDs and senior engineers, and we operate a graduate workstation with Jiangsu University of Science and Technology.