| 摘要 |
Computer-controlled method and apparatus for automatic melt index testing, including a housing with a base carrying a heater block having a bore therein for receiving a metal cartridge. A cartridge carousel is rotatably carried on the base, and carries a plurality of such cartridges, each cartridge having a plug at the bottom end thereof with a orifice through the plug, and each cartridge having a bore therein for receiving a sample of a test substance and for receiving a piston on top of the pellets. A lift arm grasps the cartridges, one at a time, and places each cartridge into the heater block, under the control of a microcomputer, by both lifting and rotating the transfer arm. The transfer arm includes a solenoid-operated grip for grasping the cartridges. The test unit carries a lift mechanism with a weight mounted atop a tamping rod, and an optical sensor for determining the height of the weight relative to the lift machinism. The weight is lowered by the lifting mechanism until it bears down upon the pellets, and then the cartridge is heated until the test substance melts. The weight is then used to extrude the melted substance through the plug orifice until it has fallen a certain distance, which operation is automatically timed by the computer. The time is then used in determining the melt index value for the substance. This operation is automatically repeated for all of the cartridges in the carousel. An automatic cut-off mechanism is used to cut off excess extrudate, and an extrudate carousel is automatically advanced to collect separate samples of the used extrudate. Optical sensors are provided to determine the motions of the components of the apparatus. |
