Comparison of Service Performance of Polyurethane and Rubber Track Pads
Q1: Why are polyurethane pads superior to rubber pads in creep resistance?
A1: Polyurethane materials have dense molecular structure, good hardness retention, are not prone to plastic deformation under long-term load, and have far stronger creep resistance than ordinary rubber. Rubber pads are prone to permanent compression deformation under high temperature and continuous pressure, with fast thickness attenuation and frequent replacement required.
Q2: What is the difference between the effects of the two pads on clip clamping force stability?
A2: Polyurethane pads have stable stiffness and small creep, small change in clip working point, and long-term stable clamping force. Rubber pads are prone to creep and thinning, clip compression decreases, clamping force continues to attenuate, requiring more frequent retightening and higher maintenance costs.
Q3: Why do high-speed lines prefer polyurethane pads?
A3: High-speed driving has extremely high requirements for track stiffness uniformity and smoothness. Polyurethane pads have small dynamic-static stiffness ratio and stable vibration reduction performance, which can effectively reduce wheel-rail impact and ensure train stability. Rubber pads have large stiffness fluctuations and are difficult to meet the strict requirements of high speed.
Q4: What is the difference in the performance of the two pads in low-temperature environments?
A4: Rubber pads tend to harden at low temperatures, elasticity decreases, vibration reduction effect deteriorates, and even brittle fracture occurs. Polyurethane pads have excellent low-temperature resistance, maintain good elasticity and toughness at low temperatures, and adapt to severe cold areas in northern China and winter low-temperature working conditions.
Q5: How to choose between the two types of pads in terms of cost and service life?
A5: Polyurethane pads have a higher unit price but a long service life and replacement cycle, with low comprehensive operation and maintenance costs, suitable for important sections such as high-speed, heavy-haul and curves. Rubber pads have low prices, suitable for ordinary low-speed lines or temporary projects, with better short-term economy.