摘要:
The present invention relates to a polyethylene terephthalate nanocomposite fiber with enhanced modulus, and specifically to a technique for preparing a PET nanocomposite fiber with excellent initial and high-temperature modulus, which comprises adding 1 to 4% by weight of a compound selected from the group consisting of C 56 H 122 O 12 Si 7 , C 31 H 71 NO 12 Si 8n , C 59 H 127 NO 12 Si 8 , and C 33 H 76 N 2 O 12 Si 8 , each of which is an organic/inorganic hybrid nanocompound, based on the total weight of the polymers, to prepare a polyethylene terephthalate nanocomposite chip having 85 mol% or more of the ethylene terephthalate units and an intrinsic viscosity in the range of 0.50 to 1.20, and then melt-spinning and stretching the composite chip.
摘要翻译:本发明涉及具有增强的模量的聚对苯二甲酸乙二醇酯纳米复合纤维,具体涉及一种具有优异的初始和高温模量的PET纳米复合纤维的制备方法,该技术包括加入1至4重量%的选自 由C 56 H 122 O 12 Si 7,C 31 H 71 NO 12 Si 8n,C 59 H 127 NO 12 Si 8和C 33 H 76 N 2 O 12 Si 8组成,各自为有机/无机杂化物 纳米复合材料,基于聚合物的总重量,制备具有85摩尔%以上对苯二甲酸乙二醇酯单元的聚对苯二甲酸乙二醇酯纳米复合材料芯片,特性粘度在0.50〜1.20的范围内,然后熔融纺丝和拉伸复合材料 芯片。
摘要:
Disclosed herein are a process for the refinement of nitrogen trifluoride gas and an adsorbent used therein. A nitrogen trifluoride (NF3) gas including carbon tetrafluoride (CF4) as an impurity is permeated into a bed of the zeolite 3 A, 4A or 5 A which is ion exchanged with alkali earth metal and is thermally treated at 150 to 600°C for 0.5 to 100 hours so as to selectively adsorb nitrogen trifluoride onto the bed, followed by the desorption of the nitrogen trifluoride therefrom.
摘要:
There is provided with a cellulose fiber suitable for industrial material which is produced by a process comprising following steps: producing NMMO solution made in a manner to dissolve 0.1wt% to 10 wt% of salt and polyvinyl alcohol in concentrated N-Methyl Morpholine N-oxide (NMMO) in liquid state; producing cellulose solution in a manner that said NMMO solution is mixed with cellulose powder and then said cellulose powder is swelled to produce cellulose solution; obtaining multifilament by solidifying said cellulose solution reached at a coagulation bath through air layer after extruded-sprayed with spraying nozzle having orifices of 500 to 2000; and winding said multifilament for storing after in turn washing, drying and treating with organic solvent, and the cellulose fiber according to the present invention is suitable for industrial materials due to excellent mechanical strength. In addition, it is possible to obtain cellulose fiber by adding salts to concentrated NMMO in liquid state, in which micro-fibril is well oriented in direction of the fiber-axis making cellulose multifilament have excellent mechanical strength and excellent stability of morphology with lower shrinkage at high temperature. Furthermore, the cellulose fiber according to the present invention has a good fibrillation-resistance and excellent adhesion to rubber by using polyvinyl alcohol when used for tire-cord.
摘要:
The present invention relates to a high tenacity polyethylene naphthalate fiber containing a silica compound. This fiber is produced by a method comprising the steps of: (A) melt-spinning a solid phase-polymerized polyethylene-2,6-naphthalate chip containing ethylene-2,6-naphthalate units at more than 85 mole% and a silica compound and having an intrinsic viscosity of 0.70-1.20, to produce a melt-spun yarn; (B) passing the melt-spun yarn through a retarded cooling zone and a cooling zone to solidify the yarn; (C) withdrawing the yarn at such a speed that the undrawn yarn has a birefringence of 0.001-0.1; and (D) subjecting the undrawn yarn to multi-stage drawing at a total draw ratio of at least 1.5 and a drawing temperature of 50-250 °C. The polyethylene naphthalate fiber has improved physical properties, such as high tenacity, and a dipped cord produced from this fiber has excellent dimensional stability and tenacity such that it can be advantageously employed as a reinforcement material of rubber products.
摘要:
Disclosed are industrial polyester fibers and preparation thereof. The industrial polyester fibers are prepared from polyester chips ranging, in intrinsic viscosity, from 1.00 to 1.15 with a moisture content of 30 ppm or less. The chips are produced through the solid-polymerization of polyester low chips comprising an antimony compound at a residual content of 200-400 ppm as calculated by antimony metal. The polyester chips are melt-spun through a nozzle contained within a pack. In the pack, the polyester chips were melted at 290-300 °C and extruded to conduits of polymer dispersing plates, each conduit having a static mixer composed of at least three units. The filaments released from the nozzle, are oiled at an O.P.U. of 0.3-0.8% with a 10-30%, aqueous emulsion oiling agent prepared from a raw solution which comprises dialkyl-thio-diester, and fatty acid monoester or alkyl alkylate at an amount of 50 weight % or greater with the dialkyl-thio-diester amounting to at least 30 weight % of the raw solution. The multifilament yarn is taken up at a speed of 2,000-3,300 m/min to obtain undrawn yarn ranging, in intrinsic viscosity, from 0.95 to 1.02 and, in orientation degree, from 40x10 -3 to 90x10 -3. The undrawn yarns are subjected to multi-step drawing to give drawn yarns which are of high tenacity and low shrinkage.
摘要:
The present invention relates to a power supply apparatus for sub-modules of a Modular Multilevel Converter (MMC), which stably supplies power to the sub-modules of the MMC in connection with an HVDC system. The power supply apparatus for sub-modules of an MMC according to the present invention includes a charging unit in which an input voltage between P and N busses of the MMC is stored, a relay unit connected in parallel with the charging unit, a resistor connected in series with the relay unit, a TVS diode connected in series with the resistor, a Zener diode connected in series with the TVS diode, a transformer for delivering the input voltage (in a primary winding) to a secondary winding thereof, a switch for switching the flow of current supplied to the transformer, a controller for enabling current to flow to the transformer by turning on the switch upon receiving a clamping voltage of the Zener diode, and a relay operation unit for operating the relay unit when the voltage output from the secondary winding of the transformer is input.
摘要:
The present invention provides a Modular Multilevel Converter (MMC) in which M redundant sub-modules are additionally arranged in addition to the N sub-modules that are needed for operation, and the N+M sub-modules are controlled so as to participate in switching in turn. The MMC according to an embodiment of the present invention includes multiple sub-modules connected in series with each other and a controller for controlling on/off switching of the sub-modules. Here, the multiple sub-modules include N sub-modules that participate in the operation of the MMC and M redundant sub-modules for replacing a failing sub-module when at least one of the N sub-modules fails, and the controller switches on the sub-module if the carrier signal assigned thereto is higher than a preset reference signal, and switches off the sub-module if the carrier signal assigned thereto is lower than the reference signal.
摘要:
The present invention provides a method for operating dual controller which monitors the state of a dual controller to determine whether the dual controller is faulty and enables operation thereof with a controller in a normal state. An operation method of a dual controller according to the present invention dq-converts control command output values of first and second controllers to calculate rates of change in dq conversion values and dq-converts feedback input values, fed back to the first and second controllers, to calculate average rates of change in dq conversion values. When the average rates of change in the dq conversion values for the control command output values and the average rates of change in the dq conversion values for the feedback input values for the respective first and second controllers are identical, the corresponding controller is determined to be in a normal state, and to be in a faulty state otherwise. According to the results of the determination, the controller in the faulty state is set to a standby state and the controller in the normal state is set to an active state.
摘要:
The present invention relates to a polyketone resin composition and to a production method therefor; and relates to a polyketone copolymer having outstanding water resistance, moisture-absorption rate and shock resistance, characterised in that the polyketone copolymer comprises repeat units represented by general formulae (1) and (2) and has an intrinsic viscosity of between 1.0 and 2.0 dl/g. Because of the outstanding moisture-absorption rate and shock resistance, the present invention can be used in, inter alia, marine bolts, clips and holders, connectors, switches, bobbins, sludge-treatment chains, cable ties, automotive fuel injection ports, green juicer screws, office partition frames and box frames.
摘要:
The present invention relates to a high-voltage direct current (DC) circuit breaker which interrupts a fault current flowing in a power transmission or power distribution DC line when a fault occurs in the DC line. The high-voltage DC circuit breaker according to the present invention comprises: a main switch, installed in the DC line, for interrupting a current in the DC line by being opened when a fault occurs in one side or the other side of the DC line; a nonlinear resistor, connected in parallel to the main switch, for consuming overvoltage; an LC circuit connected in parallel to the main switch and comprising a capacitor and an inductor that are connected to each other in series to generate LC resonance; a first switching element, connected in parallel to the LC circuit, for switching in such a manner that the polarity of a positive voltage (+VC) or a negative voltage (-VC) charged at the capacitor by the resonance of the LC circuit can be changed and charged; and a second switching element, connected between the LC circuit and the DC line so as to be connected in series to the LC circuit, for switching in such a manner that the current pulse, generated by -VC voltage or +VC voltage charged at the capacitor, can be supplied to the main switch.