Railway Plastic Dowels For Rail Screw Spike

A rail plastic dowel, also known as a rail plastic sleeve or rail plastic insulator, is a component used in railway track systems to provide electrical isolation between the rail and the fastening system, such as rail clips or screw spikes. It is made from plastic material and is inserted into the hole of a concrete sleeper (tie) or other support structure where the fastening system is anchored. The primary purpose of a rail plastic dowel is to prevent the passage of electrical current between the rail and the fasteners, enhancing electrical insulation and preventing corrosion. GNEE can provide rail plastic dowel of different types and specifications to meet the needs of customers.

Railway plastic dowels are pre-inserted into concrete sleepers to provide a secure anchoring point for rail screws. The dowel has an external thread to be screwed into the sleeper and an internal thread to receive the rail screw, which fastens the rail clip and tie plate to the sleeper. This system ensures a strong connection, prevents screws from loosening, provides electrical insulation, and improves durability and maintenance.

How Railway Plastic Dowels work?

• Anchoring: The plastic dowel is first screwed into a pre-drilled hole in the concrete sleeper, securing itself firmly with its external thread.

 

• Receiving the screw: The dowel has an internal thread that acts as a receiving nut for the rail screw.

 

• Fastening the rail: The rail screw is then driven into the dowel's internal thread, which simultaneously pulls the tie plate and rail clip tight against the rail and the sleeper.

Providing a foundation: The dowel forms the foundational part of the fastening system, ensuring a good linkage between the rail fastening system and the concrete sleeper.

Rail plastic dowels are often used in SKL rail fastening systems, our rail plastic dowels are made of HDPE or PA66 + GF30%, and the product colors are white, black and dark brown. It depends on the different technical specification requirements of customers.

HDPE rail plastic sleeve

 

HDPE is a commonly used plastic material for rail plastic dowels. It has good electrical insulation, chemical resistance and durability. Known for its strong mechanical properties and impact resistance, HDPE is well suited for railway applications.

PA66 Rail Plastic Insert

 

PA66 + GF30% can provide a balance of mechanical strength, insulation and other required properties.

Railway plastic dowels are manufactured using injection molding with high-strength plastics like polypropylene or polyamide. The raw plastic material, often reinforced with glass fibers, is heated and forced into a mold to create the final product. The resulting dowels have internal and external threads for securing screws and a smooth surface with a uniform shape for reliable performance.

Manufacturing process

• Material selection: High-performance plastics like high-density polyethylene (HDPE), polyamide (PA6 or PA66), or glass-fiber reinforced polyamide are selected for their strength, durability, and electrical insulation properties.

• Heating: The plastic granules are heated to a molten state, becoming pliable and easy to shape.

• Injection molding: The molten plastic is injected under high pressure into a pre-shaped mold that matches the final dowel design, including its internal and external threading.

• Cooling: The plastic is allowed to cool and solidify inside the mold, taking on the precise shape of the dowel.

• Demolding: Once the dowel is solid, the mold is opened, and the finished product is ejected.

• Finishing: The dowels are inspected to ensure a smooth surface and uniform threads, free from defects, to guarantee their function and interchangeability.

Key features

• Internal and external threads: The dowel has an internal thread to securely hold the sleeper screw and an external thread to provide a stable anchor in the concrete sleeper.

• Reinforcement: Many dowels are reinforced with glass fibers for increased strength and rigidity.

• Electrical insulation: The plastic material provides electrical insulation, which is a critical safety feature in railway applications.

Rail plastic dowels are typically packaged in bulk, often in 25kg plastic or woven bags, which are then secured on wooden pallets. GNEE RAIL also offer custom packaging, such as export cartons or specific bag sizes with a set number of pieces, to meet client requirements.

Standard packing methods

• 25kg bags: Dowels are packed into plastic or woven bags, with each bag weighing up to 25kg.

• Wooden pallets: Bags are often stacked and secured on wooden pallets for easier handling and transport.

• Bulk containers: Multiple pallets may be packed into a shipping container.

Customization options

• Bag size and quantity: GNEE can pack into smaller bags, such as packets containing 250 pieces, and package them in a way that is easier for smaller orders to handle.

• Export cartons: Packaging in export cartons is another option for specific shipping needs.

• Client requirements: GNEE RAIL are often able to accommodate specific packing requests based on the customer's needs.

Contact now

GNEE RAIL, as a benchmark in the railway fastener industry, is equipped with tensile testing machines to ensure product bonding strength. The railway fasteners we produce effectively absorb track vibrations and protect the sleeper structure, making them suitable for passenger-dedicated lines with high damping requirements. We support customized services for customers, providing full-process support from demand analysis, product development to logistics distribution. 

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