Preparation method of nano-silica powder-based super composite thermal insulation material

Abstract

The invention provides a preparation method of a nano-silica powder-based super composite thermal insulation material. Nano-silica powder and a functional additive are taken as raw materials, the nano-silica powder accounts for over 60% of total weight of the raw materials and the functional additive at least comprises reinforced fibers; the preparation method comprises the steps of stirring and dispersing the reinforced fibers at a rotating speed of 400-1,000r/min for 0.5-1.5 minutes; mechanically fusing the dispersed reinforced fibers, the nano-silica powder and other functional additives to complete coating modification on the surface of the functional additive by the nano-silica powder; and making the fused materials in full contact with steam at 80-85 DEG C for 28-32 minutes, extruding air and carrying out pressing, molding and drying to obtain the high-performance nano-silica powder-based super composite thermal insulation material. According to the preparation method, the supercritical drying process with strict conditions in an existing preparation technology is abandoned; and the nano-silica powder-based super composite thermal insulation material with excellent performance is prepared through a simple dry process.

Description

technical field [0001] The invention belongs to the technical field of heat insulation materials, and relates to a preparation method of heat insulation materials, in particular to a preparation method of silicon dioxide powder-based super heat insulation materials. Background technique [0002] Super heat insulation material is a heat insulation material whose thermal coefficient is lower than that of "non-convective air". Molecules collide with each other. Since the mean free path of the main components of nitrogen and oxygen in the air is about 70nm, when the micropore size inside the material is smaller than this critical size, the convective heat transfer of gas molecules is suppressed, thus obtaining a ratio " No convective air" lower thermal conductivity. Therefore, super thermal insulation materials are also called nanoporous super thermal insulation materials, among which silica airgel thermal insulation materials are currently the most researched and most represen...

AI Technical Summary

Problems solved by technology

Although there are also a lot of research using atmospheric pressure drying technology, so far this technology is only for small volume materials, and it is still in the laboratory research stage

The industrial production of silica airgel insulation materials has the following problems: first, the process is cumbersome and the preparation cycle is long; second, the supercritical drying equipment is expensive, and it is a high-temperature and high-pressure equipment, and its safe use and maintenance requirements are strict; The third is that the drying process needs to consume a lot of energy and supercritical media, and there is a problem of recycling supercritical media at the same time

However, the preparation technology of these high-temperature aerogels is not mature enough, and is still in the stage of laboratory exploration so far.

[0007] In short, the preparation process of the existing silica airgel insulation materials is complex, the supercritical drying process requires high energy consumption and high risk, and it is difficult to implement large-scale industrial production, and the silica airgel itself has mechanical properties, temperature resistance Both performance and high temperature insulation performance need to be improved

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