A new sandwich structure synthetic sleeper and its continuous pultrusion molding process

Abstract

A novel sandwich structure composite sleeper and a continuous pultrusion molding process thereof aim at the defects of larger density and smaller die cavity size of a composite sleeper. For solving the technical problems, the composite sleeper is realized by adopting the following technical scheme: the novel sandwich structure composite sleeper is characterized that the composite sleeper has a sandwich structure; the outer layer of the composite sleeper is of a continuous fiber-enhanced polyurethane foam layer with the thickness of 10-50mm; the interior of the composite sleeper is of a foam core material; the cross section of the foam core material is square or rectangle with round angels chamfered at four corners; the material of the foam core material is one from polyurethane foam, polyvinyl chloride foam and phenolic foam, and the density of the material is 100-500kg/m<3>. The continuous molding process for the composite sleeper comprises six procedures of yarn guiding, conveying of the foam core material, glue injecting of a foaming machine, uniform dipping, molding and cutting. The technology has the advantages of small density, large bearing strength, simple and convenient procedures, high cost performance and the like.

Description

technical field [0001] The invention relates to the technical field of composite materials, in particular to a novel composite sleeper structure with a sandwich structure and a manufacturing method thereof. Background technique [0002] Railway is one of the main means of transportation in my country. Railway sleepers usually use wooden sleepers and reinforced concrete sleepers. As traditional wooden sleepers, they are easy to process and transport, have high insulation performance, and excellent vibration reduction performance. However, because their materials are biological materials, although After anti-corrosion and waterproof treatment, its service life is still relatively short, generally no more than 15 years, and its maintenance cost is relatively high. As a replacement material for wooden sleepers, reinforced concrete sleepers are increasingly difficult to meet the development needs of railway construction due to their shortcomings such as heavy weight, high brittlen...

AI Technical Summary

Problems solved by technology

The above patents are all long-fiber reinforced polyurethane homogeneous foam materials. Some patents form a flame-retardant layer on the surface crust during the molding process of synthetic sleepers. The main molding process adopts continuous pultrusion molding process, but the above synthetic sleepers all use Homogeneous material, the density of the product is relatively high, usually greater than 750kg / m3. At the same time, in order to facilitate the arrangement and infiltration of yarn bundles, and to prevent core burning caused by high internal heat release, the maximum molding cavity size is usually controlled at 210mm×80mm. When making sleepers, block-to-block bonding is required, which virtually increases the production cost of synthetic sleepers

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