Rail systems act as a means of transportation, whether it be groups of people commuting on the subway or a freight train delivering goods across the country. As opposed to road transport, in which the vehicles travel on a flat surface, rail transport is reliant on tracks.
Railroad structure consists of rails, fasteners, railroad ties, ballast, and the subgrade. The traditional structure has flat-bottom steel rails that are supported by timber or pre-stressed concrete ties, laid on top of crushed ballast. A plastic or rubber pad (called a tie pad) is placed between the rails and tie plates when using concrete ties. Ballastless tracks, on the other hand, are constructed using a continuous concrete slab with rails embedded directly on the surface, supported by tie pads.
Regardless of the track design, railroads are subject to tension and shear loads, as well as heavy vibration and noise. Extruded profiles are used to protect tracks and provide vibration dampening. Rubber and thermoplastic materials are ideal for railroad use because they are nonconductive (unable to conduct heat, electricity, or sound) and provide good to excellent shear and tensile strength. Thermoplastics are high strength, lightweight and provide excellent wear resistance, impact resistant and chemical resistance. They perform well in rail applications because of their excellent flex fatigue, durability and resistance to creep and tearing. Similarly, elastomeric materials are rubber compounds that resist tearing and breaking and have excellent heat and chemical resistance. The flexibility, durability and insulative properties of elastomers makes them perfect for vibration dampening, electrical insulation and noise reduction.
Our railroad products include rail boots, grout, and tie pads made from durable thermoplastic or elastomeric materials. Rail boots are embedded in the tracks themselves. They help to absorb vibrations, reduce noise, insulate against electricity, and reduce wear and tear. Grout fills the space between rail structures and the concrete slabs, providing electrical resistance, vibration absorption, and noise reduction. Tie pads sit between rail tie plates and the foot of the rail, protecting steel rails and ties from wear and tear. They distribute the load placed on the ties which reduces shock, vibration, and noise, creates a smoother ride for passengers, and reduces wear and tear over time. We also hold two US patents for railroad crossing tie pads and elastomeric under tie pads.
Northwest Rubber Extruders offers a full line of high quality, high performance railroad equipment and supplies. Request a quote on the thermoplastic and elastomeric rail products you need, or contact us for more information.