Black Pipe Granules

Updated: 2026-09-11

Overview

Black Pipe Granules are specialized high-density polyethylene (HDPE) compounds engineered for pipe extrusion. These granules contain carbon black (2-3%) for UV protection and additives to enhance oxidative resistance. Meeting ISO 4427 and ASTM D3350 standards, they are the raw material for durable piping systems with 50+ year service life. Manufacturers typically produce these granules using bimodal HDPE technology, which optimizes molecular weight distribution for both processability and end-product strength. The black coloration is critical for outdoor applications, providing protection against solar degradation.

Physical and Chemical Properties

The material exhibits a melt flow index (MFI) of 0.1-0.4 g/10min (190°C/5kg), balancing extrusion ease with mechanical performance. Its hydrostatic design stress reaches 10 MPa (PE100 grade), with notch test resistance exceeding 1,500 hrs at 80°C. Chemically, the granules resist acids, alkalis, and salts up to pH 2-12, making them suitable for industrial effluent systems. The carbon black dispersion ensures ≥97% UV screening efficiency. Typical ash content remains below 0.05%, ensuring purity for potable water applications.

Main Applications

Primary use is in manufacturing pressure pipes for municipal water supply (SDR11/SDR17 ratings), with diameters ranging from 20mm to 1200mm. In gas distribution, yellow-striped variants comply with ISO 4437 for medium-pressure networks (up to 10 bar). Corrugated double-wall drainage pipes account for 30% of consumption, particularly in highway and agricultural projects. Emerging applications include marine outfall pipes (saltwater resistant) and geothermal ground loops, where temperature resistance to 60°C is critical.

Safety and Storage

Though chemically inert in solid form, processing at 160-220°C requires local exhaust ventilation due to potential volatile emissions. NFPA 704 rates the material as health hazard 1 (slight) and flammability 1 (low). Storage recommendations include palletized bags (500-1000kg) with moisture-proof lining. Shelf life exceeds 12 months if kept below 30°C and 60% RH. Bulk silo storage requires nitrogen blanketing to prevent oxidative degradation during extended periods.

B2B Procurement Guide

Key specifications to verify include MRS classification (PE80/PE100), carbon black content (2.5±0.5%), and hydrostatic pressure test results. Reputable suppliers provide third-party certification from bodies like NSF or DVGW. For large projects, request production batch records to ensure consistency. Consider ordering trial quantities (1-5 tons) for extrusion testing before full procurement. Logistics planning should account for bulk container (20-25 tons) or flexitank (18-20 tons) options for cost efficiency.