A 3D printing nozzle calibration system, comprising a heated chamber; a printing base plate mounted inside the heated chamber; printing base moving means configured to move the printing base plate; a moving carriage; at least one rail on which the moving carriage is configured to slide up and down; a printing nozzle partially mounted inside the heated chamber; the printing nozzle is connected to the moving carriage; a hard stop connected to the moving carriage; a fixed part on which the hard stop is resting; and a printer controller; wherein the printing base plate is configured to move up, up to a point where the printing base plate touches the printing nozzle in a determined point of the printing base plate, thereby causing the hard stop to disconnect from the fixed part; and wherein the printer controller is configured to store a height of the printing base plate upon the disconnection.

The present disclosure provides a thermal insulation apparatus and a crucible production device. The thermal insulation apparatus is configured for supporting a mold, and includes: a housing, a first flange, a second flange and a plurality of reinforcing members, and the housing, the first flange and the second flange are coaxially arranged. An inner wall of the housing is enclosed to form an accommodating cavity, and the accommodating cavity is configured for accommodating the mold; a water-cooling cavity is enclosed between the inner wall and an outer wall of the housing; the first flange is connected to a top portion of the housing, so as to fix an upper edge of the mold to the top portion of the housing; the second flange is connected to a bottom portion of the housing; and the plurality of reinforcing members are arranged between the bottom portion of housing and second flange.

The present disclosure provides a thermal insulation apparatus and a crucible production device. The thermal insulation apparatus is configured for supporting a mold, and includes: a housing, a first flange, a second flange and a plurality of reinforcing members, and the housing, the first flange and the second flange are coaxially arranged. An inner wall of the housing is enclosed to form an accommodating cavity, and the accommodating cavity is configured for accommodating the mold; a water-cooling cavity is enclosed between the inner wall and an outer wall of the housing; the first flange is connected to a top portion of the housing, so as to fix an upper edge of the mold to the top portion of the housing; the second flange is connected to a bottom portion of the housing; and the plurality of reinforcing members are arranged between the bottom portion of housing and second flange.

Lithium silicate materials are described which can be easily processed by machining to dental products without undue wear of the tools.

Lithium silicate materials are described which can be easily processed by machining to dental products without undue wear of the tools.

The present disclosure relates to glass manufacturing, a glass composition, glass with a low inclusion content and a preparation method therefor and use thereof. The composition comprises 50-64 wt. % SiO.sub.2, 14-24 wt. % Al.sub.2O.sub.3, 0-7 wt. % B.sub.2O.sub.3+P.sub.2O.sub.5, 0.5-7 wt. % MgO, 1-10 wt. % CaO, 0-9 wt. % SrO, 0.1-14 wt. % BaO, 0.1-5 wt. % ZnO, 0.1-4 wt. % TiO.sub.2, 0.1-7 wt. % Y.sub.2O.sub.3+La.sub.2O.sub.3+Nd.sub.2O.sub.3, and <0.05 wt. % R.sub.2O, wherein R.sub.2O is a sum of the content of Li.sub.2O, Na.sub.2O and K.sub.2O, and the composition satisfies the following conditions: (1) a temperature T.sub.100 corresponding to a viscosity of 100 P is 1730° C. or higher; (2) a surface tension at 1300° C. is less than 420 mN/m. The glass prepared by the glass composition and the glass with a low inclusion content preparation method has the advantages of having low inclusion content, having a simple preparation process, being low in cost and so on.

The present disclosure relates to glass manufacturing, a glass composition, glass with a low inclusion content and a preparation method therefor and use thereof. The composition comprises 50-64 wt. % SiO.sub.2, 14-24 wt. % Al.sub.2O.sub.3, 0-7 wt. % B.sub.2O.sub.3+P.sub.2O.sub.5, 0.5-7 wt. % MgO, 1-10 wt. % CaO, 0-9 wt. % SrO, 0.1-14 wt. % BaO, 0.1-5 wt. % ZnO, 0.1-4 wt. % TiO.sub.2, 0.1-7 wt. % Y.sub.2O.sub.3+La.sub.2O.sub.3+Nd.sub.2O.sub.3, and <0.05 wt. % R.sub.2O, wherein R.sub.2O is a sum of the content of Li.sub.2O, Na.sub.2O and K.sub.2O, and the composition satisfies the following conditions: (1) a temperature T.sub.100 corresponding to a viscosity of 100 P is 1730° C. or higher; (2) a surface tension at 1300° C. is less than 420 mN/m. The glass prepared by the glass composition and the glass with a low inclusion content preparation method has the advantages of having low inclusion content, having a simple preparation process, being low in cost and so on.

A screw smelting machine melts raw materials with a different chemical ratio in a mixing funnel in a feeding order to prevent the long-range diffusion of a melt, and controls outflow at a suitable speed. A centrifugal casting machine solidifies the melt with the ingredients gradient varying into a radial ingredient gradient material by a centrifugal casting style. A temperature sensor monitors temperature of an outer surface of a centrifuge cavity of the centrifugal casting machine during centrifugal casting, and transmits the temperature to a control platform. The control platform determines an optimal flow rate of the melt at an end of screw rod according to ingredient gradient of ingredient radial-gradient pipe materials and a thickness of each component gradient material required with preparation, in combination with a real-time data fed back from the temperature sensor, and feeds back to a feeding end.

A screw smelting machine melts raw materials with a different chemical ratio in a mixing funnel in a feeding order to prevent the long-range diffusion of a melt, and controls outflow at a suitable speed. A centrifugal casting machine solidifies the melt with the ingredients gradient varying into a radial ingredient gradient material by a centrifugal casting style. A temperature sensor monitors temperature of an outer surface of a centrifuge cavity of the centrifugal casting machine during centrifugal casting, and transmits the temperature to a control platform. The control platform determines an optimal flow rate of the melt at an end of screw rod according to ingredient gradient of ingredient radial-gradient pipe materials and a thickness of each component gradient material required with preparation, in combination with a real-time data fed back from the temperature sensor, and feeds back to a feeding end.

A method of manufacturing a heat exchanger core from glass ceramic matrix composite includes placing one or more reinforcing fibers around one or more mandrels into a mold cavity. A glass matrix material infiltrates the one or more reinforcing fibers to produce an infiltrated core and the one or more mandrels is removed to create one or more passages passing through the infiltrated core.