tailieunhanh - Conductive Polymers and Plastics in Industrial Applications Part 5

Tham khảo tài liệu 'conductive polymers and plastics in industrial applications part 5', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Creation of Electrically Conducting Plastics 79 long cylindrical glass tube of inner diameter Dị 36 mm was housed in an electrically heated oven. The tube was attached to a lower shaft which was rotated by a servo motor. A cylindrical steel rod of diameter D2 13 mm descended into the glass tube and was rotated by a separate servo motor via an upper shaft. The axes of the tube and the rod were parallel and offset by e mm. The servomotors were connected to the rod or tube via 100 1 speed reduction gear boxes and were controlled by a digital motion controller with a servo-amplifier. The controller was programmable through a personal computer. Prior to processing the mixture of filler-rich and filler-free pellets was melted to remove voids. Additional pellet mixture was placed into the cavity in order to replace the void volume. In this manner the mixing cavity was filled with a large vertical void-free span of pellets where two-dimensional mixing conditions could be induced. Prior to activating the servo motors the mixture was melted by heating the oven to 210 C and maintaining this temperature for 15 minutes. In order to instill chaotic advection each cylinder was rotated periodically and separately for a specified angular displacement 0 and then stopped. One complete set of rotations comprised one mixing period. Equal linear displacements at the surface of the two boundaries and equal times for rotation were imposed by setting the angular displacement and the angular velocity ratios equal to the diameter ratio 0 1 O 2 01 02 D2 D1 with 0 1 01 1 rpm. The geometry and mixing protocol were selected according to the results of Swanson and Ottino 12 such that chaotic mixing prevailed throughout the cavity. At the end of mixing the sample was solidified by discharging an air jet array onto the glass tube. After removal from the oven the glass tube was broken and the steel rod was dislodged so as to free the sample for subsequent examination and testing. A