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1. A soundproof door for use in reduction of sound transmitted from one side of the door to the other side, having a thickness of 30-70 mm as well as having an STC number greater than of STC 30 determined in accordance with ASTM E413-10 and E90-09, comprising
two door skins one formed as a front door skin and the other formed as a rear door skin for the soundproof door respectively, and a quadrilateral frame constituted by a top rail member, a bottom rail member, a left stile member and a right stile member to seal the perimeter of the door skins; wherein the improvement comprises: a multiple-layered core to form a concrete inner portion of the door, which comprising;
two spaced hard-soundproofing cores each formed as a single-layered soundproofing core having a thickness of 3-12 mm and made of wood plate, iron plate, calcium silicate board, gypsum board, magnesium oxide board, silicon magnesium board, glass fiber composite board or ceramic composite board; anda soft-soundproofing core interleaved in between the spaced hard-soundproofing cores to constitute with a sandwich structure, and the soft-soundproofing core is made of rock wool fiber board, ceramic fiber wool board, phenolic foaming board, glass fiber board, closed cell polyurethane foaming board, opened cell polyurethane foaming board, expandable polystyrene foaming board or expandable polyethylene foaming board. |
