SIKORA and Jiangsu Keling Upgrade Pellet Inspection System to Improve Quality Control During Manufacturing
Bremen, Germany, 4 September 2026 – In the production of high-voltage cable insulation materials, pellet purity and process stability are key factors in ensuring the reliability of the finished product. Jiangsu Keling New Material Co., Ltd., a technology company specialising in the research and manufacture of insulation materials for high-voltage AC and DC land and submarine cables rated at 110 kV and above, continually strives to achieve the highest standards of purity and performance in its quality control processes.
To benchmark its performance against leading companies worldwide, Jiangsu Keling has introduced SIKORA’s inspection, sorting and analysis systems, establishing a comprehensive quality assurance process from raw materials to finished products to help ensure the reliability of extra-high-voltage cables.
One System for Detecting Metallic Impurities and Discolouration
During the long-term operation of extra-high-voltage (EHV) cables under complex service conditions, even the smallest metallic impurities or discolouration within the cable insulation material can trigger partial discharge or lead to cable failure. Traditional sampling inspection methods have limitations, increasing the risk of contaminants going undetected.
Jiangsu Keling is the first company in China to implement a comprehensive inspection system capable of detecting both metallic impurities and discolouration. The system provides extensive inspection coverage, traceability and measures to prevent secondary contamination, helping the company meet stringent purity requirements.
Jiangsu Keling has integrated six PURITY SCANNER ADVANCED inspection and sorting systems from SIKORA into its production line, alongside a PURITY CONCEPT V offline inspection and analysis system. Together, these systems establish a dual-mode quality control process combining 100% online inspection with offline sample testing.
100% Online Inspection System
Jiangsu Keling optimised its production line layout to ensure the six PURITY SCANNER ADVANCED systems were evenly distributed, enabling 100% online inspection.
The system combines X-ray technology with an optical camera to detect metallic impurities measuring 50 µm or larger inside pellets, as well as black specks and discolouration measuring 25 µm or larger on pellet surfaces.
A specially designed stainless-steel vibrating chute avoids common problems associated with conveyor belt systems, including material leakage, belt misalignment and secondary contamination. When contaminated pellets are detected, particularly those containing metallic impurities, the system automatically activates adjustable hybrid blow-out settings and extends the blowing duration to improve the removal of contaminated material.
Offline Inspection and Analysis System
Samples of incoming materials and production batches are tested to support batch approval, contamination analysis and data verification. The results are cross-referenced with online inspection data to establish a traceable record from raw materials to finished products.
Using SIKORA’s PURITY CONCEPT V offline inspection and analysis system, Jiangsu Keling can examine material samples in greater detail. Within less than a minute, optical contaminants measuring 50 µm or larger can be detected, analysed and assessed, with the results presented in a report.
Results: Improved Control of Pellet Purity
Following the implementation of SIKORA’s inspection, sorting and analysis systems, Jiangsu Keling has achieved stable and reliable quality in its finished insulation materials, with all products meeting the required performance standards.
“Our biggest concern previously was that impurities could affect cable reliability. The SIKORA systems not only offer high inspection precision, but the vibrating chute design also minimises secondary contamination at the source. Maintenance costs are much lower than we expected, too. Since implementation, our product pass rate has consistently remained at the industry’s leading level, and customer recognition of our product purity has increased significantly,” said the Production Director of Jiangsu Keling.
He added that the inspection solution has become a key part of maintaining the consistent quality of Jiangsu Keling’s extra-high-voltage insulation materials.
With SIKORA’s inspection, sorting and analysis systems in place, Jiangsu Keling has strengthened its position as a supplier in China’s domestic extra-high-voltage insulation materials market, supplying materials for major projects involving offshore wind power and ultra-high-voltage (UHV) transmission.
