Long glass fiber reinforced hard polyurethane synthetic material sleeper and method for preparing the same

Abstract

The invention discloses a sleeper made of hard polyurethane synthesized material intensified by long glass fiber and a preparation method thereof; the sleeper has low densityííand long service life and is easy to be processed and installed, and the preparation method thereof is also simple. The sleeper made of hard polyurethane synthesized material intensified by long glass fiber is made from the following materials by weight proportion: 100 portions of composite material of polyurethane raw liquor and 30 portions to 50 portions of long glass fiber; wherein the composite material of polyurethane raw liquor consists of polyol component I and isocyanate component II, and the weight ratio of the component I to the component II is 1: 1 to 1: 1.25.

Description

technical field [0001] The invention relates to a sleeper and a preparation method thereof, in particular to a long glass fiber reinforced rigid polyurethane synthetic material sleeper and a preparation method thereof. Background technique [0002] Railway is currently one of the most important means of transportation in the world. With the development of railways towards high speed, heavy load and environmental protection, the requirements for rails are getting higher and higher. Sleepers are an important part of rails, and their materials and structures are Constantly developed and updated. Currently used sleepers mainly include wooden sleepers, steel sleepers and concrete sleepers. As a sleeper commonly used in traditional railway tracks, although wood sleepers have the advantages of low cost, high elasticity, light weight, and good insulation, they also have insurmountable shortcomings, mainly in: easy weathering and cracking, short service life, generally only 15 year...

AI Technical Summary

Problems solved by technology

As a sleeper commonly used in traditional railway tracks, although wood sleepers have the advantages of low cost, high elasticity, light weight, and good insulation, they also have insurmountable shortcomings, mainly in: easy weathering and cracking, short service life, generally only 15 years; more importantly, it consumes a large amount of forest resources and causes serious environmental problems

Steel sleepers have been used in some countries in Europe and South America. The advantages are: long service life, up to 50-60 years; large sleeper spacing to reduce consumption; can be made by smelting a large amount of scrap iron and steel, and can be returned to the furnace after being scrapped. However, its disadvantages are: high cost, heavy volume, and high noise, so it cannot be widely used

Concrete sleepers are one of the sleepers commonly used at present. They have the advantages of long life and good stability. The main disadvantages are high hardness, poor elasticity, poor sound attenuation and shock absorption, and cracks are prone to appear during use; more importantly, post-processing is difficult. , so the installation accuracy is limited

[0003] At present, the sleepers used in China's railways are mainly wooden sleepers and reinforced concrete sleepers. Since the 1990s, due to the development of high-speed railways and linear motor carrying systems in foreign countries, efforts have been made to study new material sleepers. The United States took the lead in large transfer stations and The installation and use of the main line-plastic sleepers. Later, other types of composite sleepers have also begun to be used on a small scale in Japan, South Korea, Russia, etc., but the general plastic sleepers cannot meet the strength and shock absorption performance requirements of the sleepers themselves. Reinforced or modified composite materials can meet the requirements of use. Glass fiber reinforced rigid polyurethane composite material is a composite material that has received extensive attention and use recently. Generally, short fibers are used to reinforce polyurethane foam, such as "Macromolecular Materials Science Engineering and Engineering, 2001, 17(3) "Compression Properties of Short-cut Glass Fiber Reinforced Rigid Polyurethane Foam", "Application of Engineering Plastics", 2003, 31(7), "Research Progress of Glass Fiber Reinforced Rigid Polyurethane Foam", etc. All disclosed in the article are short-fiber reinforced rigid polyurethane foams, but their strength and other properties cannot meet the requirements of sleepers. When reinforced with long fibers, although the strength is high, if the production process cannot solve the problem of uniform distribution of long fibers, The formed synthetic material is difficult to apply because of the agglomeration and bending of long fibers, resulting in inhomogeneous material properties and local stress concentration.

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