Fiber-reinforced polyurethane foamed and synthesized sleeper and preparation method thereof

Abstract

The invention discloses a fiber-reinforced polyurethane foamed and synthesized sleeper and a preparation method thereof. The sleeper comprises a body formed by polyurethane resin in a one-time lamination manner, wherein multiple layers of composite felts with a transverse reinforcing effect are transversely arranged in the body, and a fiber yarn layer with a longitudinal reinforcing effect penetrates into the polyurethane resin between two adjacent composite felts; the fiber yarn layer and the composite felts account for 65%-75% of the total weight of the sleeper; the polyurethane resin accounts for 25%-35% of the total weight of the sleeper, and the density of the sleeper is 0.6g / cm<3>-1.6g / cm<3>; and the sleeper is prepared through combination of a double-steel belt laminating machine and a multilayer synchronous glue injection primary formation. According to the fiber-reinforced polyurethane foamed and synthesized sleeper, gum dipping is relatively adequate and uniform, so that thetransverse strength of the sleeper is enhanced, and the cracking phenomenon of a product during punching and indenting can be avoided; and the production process is simple, the equipment input is reduced, the production cost is lowered, and the production efficiency is improved.

Description

technical field [0001] The invention relates to the technical field of rail transportation, in particular to a sleeper used on railways, subways and light rails and a method for preparing the sleepers. 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 tracks are getting higher and higher. As an important part of track, sleepers play an important role in track construction. play a vital role. In the track structure, the role of the sleeper is to bear the load, lateral force and longitudinal horizontal force transmitted from the rail, and spread it evenly on the track bed; at the same time, the sleeper also plays the role of maintaining the direction, gauge and position of the rail. Therefore, the sleeper is required to have certain firmness, elasticity and durability, and the size of the sleeper is...

AI Technical Summary

Problems solved by technology

Among them, wooden sleepers, as sleepers commonly used in traditional railways, have the advantages of low cost, high elasticity, light weight, and good insulation performance. However, due to limited forest resources, long-term felling will cause serious environmental problems. In addition, wooden sleepers have been exposed to harsh environments for a long time. , there are disadvantages such as poor anti-corrosion performance, easy weathering and cracking, short service life, poor durability, poor physical and mechanical properties, and poor pull-out performance of gauge spikes; steel sleepers are mainly made of a large amount of scrap iron and steel, and have a long service life, but There are disadvantages such as high cost, bulky, and loud noise; concrete sleepers are the most widely used sleepers at present, with long life and good stability. Cracks and other problems are prone to occur in the middle; polyurethane synthetic sleepers are a new type of sleepers, which have the advantages of light weight, excellent physical and mechanical properties, good pull-out performance of gauge spikes, and rich synthetic material resources. They have gradually replaced traditional wooden sleepers. The use of steel sleepers and concrete sleepers

[0004] At present, the processing technology of synthetic polyurethane sleepers is relatively complicated. It is necessary to produce plates first. After grinding and setting the thickness, they are bonded with adhesives. After bonding, both sides of the overall sleeper need to be polished and painted.

The preparation method of this kind of polyurethane sleeper has the following defects: 1) Since it is all made of multi-layer boards bonded by an adhesive, it cannot be formed at one time, resulting in poor overall performance of the sleeper, and the bonding layer is prone to cracking and faults and other problems; 2) Each layer of the board has only 0° direction fibers, no 90° direction fibers, low transverse strength, and easy to crack when opening holes and grooves; 3) The production equipment is simple, and basically adopts the method of spraying glue and manually kneading , and then enter the mold of the double-track laminator, the width is larger when the glue is sprayed, the width is narrower after entering the mold, the shrinkage angle is large, the distribution on both sides and the middle is uneven, and the resin and fibers of the upper and lower layers are uneven; 4) Processing During the process, manual dipping or manual assisted dipping is required, and the formed board can be bonded after double-sided grinding and thickness determination. The bonding time is long. Usually, each laminator can bond a sleeper every 24 hours. , low efficiency; 5) The laminator consists of at least 500 chain plates, the length of the chain plates is 20cm, and there are inevitably gaps between the chain plates. During the curing and molding process, the polyurethane foam will be extruded, resulting in mold marks, and the extruded foam Difficult to clean up, serious waste of raw materials

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