HSE吊装作业课件.ppt

* * * * * * * * * * * * * * * * * Fiber cores are ropes made from fibers formed into yarns, then into strands and finally into the finished core form. There are two general types of fiber: natural vegetable material, such as sisal, manila and cotton and synthetic filaments, such as polypropylene or polyethylene. Steel cores may be an independent wire rope (IWRC) or, in the case of small diameter ropes and some rotation-resistant ropes, a wire strand core (WSC). These steel cores provide more support than fiber cores to the outer strands during the rope’s operating life. Steel cores resist crushing, are more resistant to heat, reduce the amount of stretch, and increase the strength of the rope. * * Fiber cores are ropes made from fibers formed into yarns, then into strands and finally into the finished core form. There are two general types of fiber: natural vegetable material, such as sisal, manila and cotton and synthetic filaments, such as polypropylene or polyethylene. Steel cores may be an independent wire rope (IWRC) or, in the case of small diameter ropes and some rotation-resistant ropes, a wire strand core (WSC). These steel cores provide more support than fiber cores to the outer strands during the rope’s operating life. Steel cores resist crushing, are more resistant to heat, reduce the amount of stretch, and increase the strength of the rope. * In regular lay ropes, the wires in the strands are laid in one direction, while the strands in the rope are laid in the opposite direction. The result is that the wire crown runs approximately parallel to the longitudinal axis of the rope. These ropes have good resistance to kinking and twisting and are easy to handle. They are also able to withstand considerable crushing and distortion due to the short length of exposed wires. This type of rope has the widest range of applications. * Have the class members provide their thoughts of suitable allowances Write the student ‘guess’ on the board for future discuss