Production of aerogel thermal insulation sheet by central injection approach

A preparation method for mass-producing an aerogel-fiber thermal insulation sheet by a central injection approach, the preparation method comprising:

• a mixing and hydrolysis step in which:
• a siloxane precursor is added into an ethanol-based dispersion solvent to form a mixed solution, and an acidic catalyst is subsequently added into the mixed solution in order for hydrolysis to take place, wherein the siloxane precursor includes one or a combination of a hydrophobically modified siloxane compound whose original alkyl group is substituted by an alkyl group of a different alkyl chain length and a siloxane compound;
• a condensation and dispersion step in which:
• the mixed solution is added with a basic catalyst in order for condensation to take place, thereby producing a hydrolyzed mixed siloxane compound, and the hydrolyzed mixed siloxane compound is subsequently added with an azeotropic dispersion solvent and added with an organic material or an inorganic material and is stirred at high speed in order for the hydrolyzed mixed siloxane compound to form suspended and dispersed sol droplets, and for the suspended and dispersed sol droplets to be condensed in the azeotropic dispersion solvent to form a condensed dispersed sol solution;
• a central injection step in which:
• a pressure difference is created between two sides of a fiber substrate to allow the condensed dispersed sol solution to be rapidly injected through a central injection tube or a central injection plate into the fiber substrate from an inner portion thereof outward along a pressure decreasing direction of the pressure difference, thereby forming an aerogel-fiber composite material, wherein the pressure difference includes a pump pressure difference or a vacuum pressure difference, and wherein the fiber substrate includes a rolled fiber substrate or a multilayer sheet-like fiber substrate;
• a drying and solvent recycling step in which:
• a high-temperature dry airflow or a supercritical fluid is made to spread rapidly from the central injection tube or the central injection plate along the pressure decreasing direction and thus into the aerogel-fiber composite material from an inner portion thereof outward such that the azeotropic dispersion solvent in the aerogel-fiber composite material, which has a stable structure, is rapidly vaporized and dried at a solvent recycling temperature, wherein the solvent recycling temperature is between 30° C. and 180° C. or is at least 240° C.;
• a hot-pressing and solvent recycling step in which:
• the aerogel-fiber composite material is hot-pressed by a high-temperature high-pressure hot press or is hot-pressed by the high-temperature high-pressure hot press after the aerogel-fiber composite material and a fiber substrate-based protective layer are stacked up or after the aerogel-fiber composite material is spray-coated with a high-temperature-resistant adhesive-based protective layer, in order to form an aerogel-fiber composite fireproof/thermal insulation material having a single-layer, sandwiched, or multilayer structure;
• and
• an automatic cutting step in which:
• the aerogel-fiber composite fireproof/thermal insulation material is cut into one or a plurality of aerogel-fiber thermal insulation sheets by automatic cutting equipment.