Hyundai Motor Company

Young-Ho Choi

Chi-Hoon Choi

Do Suck Han

Disclosed is a continuous carbon fiber/thermoplastic resin fiber composite yarn and a method for manufacturing the same, wherein the carbon fiber composite yarn provides excellent mechanical properties, is light in weight, moldable, and has excellent impregnating ability. In particular, the composite yarn is provided with these superior properties by including a continuous carbon fiber having excellent mechanical properties, a thermoplastic resin fiber, and the like, and by using a false twist processing machine or a solution bath, and the like in order to manufacture the composite yarn.

Continuous carbon fiber/thermoplastic resin fiber composite yarn and method for manufacturing the same

Disclosed is a method for preparing hollow carbon fibers having an empty space in the cross section thereof. More specifically, the disclosed method includes preparing a spinning solution of an acrylonitrile-based polymer having a viscosity ranging from 2000 to 5000 poise at room temperature; spinning the prepared spinning solution using a spinneret designed for spinning hollow fibers; super-drawing and drawing spun fibers to prepare hollow precursor fibers; and stabilizing and carbonizing the hollow precursor fibers to prepare the hollow carbon fibers. The hollow carbon fibers obtained by the disclosed method have a lower specific gravity by 10 to 50% than conventional hollow carbon fibers (solid), but have similar mechanical properties to the conventional fibers. Furthermore, in the method, the diameter of carbon fibers can be adjusted. Thus, it is possible to widen the application of hollow carbon fibers.

Preparation method for hollow carbon fiber

Disclosed is a method for preparing hollow carbon fibers having an empty space in the cross section thereof. More specifically, the disclosed method includes melt-spinning an acrylonitrile-based polymer by using a supercritical fluid as a plasticizer; drawing spun fibers to prepare hollow precursor fibers; and stabilizing and carbonizing the hollow precursor fibers to prepare the hollow carbon fibers. The hollow carbon fibers obtained by the disclosed method have at least a 10 to 50% lower specific gravity than conventional hollow carbon fibers (solid), but have similar mechanical properties to the conventional fibers. Furthermore, the diameter of carbon fibers can be adjusted, thereby making it possible to widen the application of hollow carbon fibers.

Preparation method for hollow carbon fiber using supercritical fluid

The warning apparatus includes magnetic force generating units, each oppositely arranged about a timing belt to generate a mutually opposite polarity of a magnetic force. A voltage inducing unit is disposed at one lateral surface of the timing belt to induce a voltage in response to the magnetic force generated from the magnetic force generating units. A voltage detecting unit detects the voltage induced by the voltage inducing unit. A controller outputs a control signal for generating a warning signal when the voltage detected by the voltage detecting means is less than an established level. A warning generating unit generates an alarm that a replacement time of a timing belt has arrived in response to the control signal from the controller, such that when a timing belt is worn to a degree of breakage, a warning signal is given by a detection thereof so that a healthy timing belt should not be changed periodically.

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Gyeonggi-do, South Korea

Young-Ho Choi