Mechanical modification of softwood pulp fibers using a novel lightweight vertical bar plate

Refiner plates made using sand casting have a draft angle, which results in a trapezoidal bar shape. These trapezoidal bar plates have a limited throughput compared to the vertical bar plates, and eventually the edges of the bars become dull, resulting in longer time to reach the target freeness and shorter service life. The new light-weight refiner plate with a bar insertion method into a plate base was developed by selecting an aluminium-based alloy as the plate base material and a stainless steel alloy with high wear resistance as the bar material. The light-weight plate with sharp bar edges was very effective in reducing refining energy by reaching the target freeness faster than the sand-cast bar plate. Finally, the lightweight sharp bar plate, which weighed only about half the weight of the cast bar plate, was expected to significantly contribute to easy replacement, improved paper quality, and larger throughput without excessive loss of fiber length.

Experiment and Simulation Research on the Fatigue Wear of Aircraft Tire Tread Rubber

The road surface and the tread pattern structures directly affect the wear performance of aircraft tire, especially for lateral sliding conditions. In this paper, wear tests of tread block with different draft angles and root radiuses, different interfaces, and different slip angles were carried out, and combined with the simulation, the effects of tread groove structure and slip angle on the wear mechanism were analyzed. Results indicated that the influences of draft angle were greater than the root radius; the wear geometry of the tread block decreased when the draft angle increased in the range of 0° to 15°, but for the root radius, the wear geometry of each sample was similar to a strip shape. A considerable material loss occurred at the front edge when the slip angle increased, and the slip angle was larger in the range of 0° to 45°. Combined with the simulation and wear test, fatigue wear and abrasive wear of the slide surface are dominant factors when considering the effects of tread groove structure and slip angle, and both front edges of the tread blocks roll up repeatedly; the coefficient decreases with the increase in load when the cement concrete pavement interface is dry, but for a wet interface, the coefficient decreases softly.

Fabrication of aluminum bipolar plates with Archimedes' screw-shaped channels: a rubber pad forming process assessment

Bipolar plates are one of the most important components of polymer membrane fuel cells. In this manuscript, the rubber pad forming of aluminum bipolar plates with Archimedes' screw-shaped channels and draft angle of 90$$^\circ$$ ∘ has been investigated. Hence, all possible combinations of the process parameters were determined and corresponding experimentations performed in order to investigate the effects of the rubber hardness, punch speed and the hydraulic press force. In this regard, three rubber pads including polyurethane, silicone and natural rubber were used. Channel depth and thinning percentage in the corner of the channel are measured and the effect of each parameter is analyzed. Based on the results, the maximum channel depth was achieved using a silicone pad with a hardness of 60 Shore A. Using a rubber pad with a very high and low hardness number, both, reduces the depth of channel. Furthermore, as the punch speed increases, the channel depth increases and the thinning percentage, as well.

New technology for developing a lightweight refiner plate for hardwood kraft pulp fibers

Sand casting makes it difficult to manufacture a fine bar plate for low intensity refining. This study introduced a novel technology for manufacturing lightweight fine bar plates and compared the effects to traditional bar plates. The lightweight fine bar plate base was manufactured using a lightweight aluminum alloy and stainless-steel. Because the bars were inserted into the plate vertically without the draft angle, the stock throughput was improved by approximately 27% compared to the sand-casted bar plates. Additionally, the lightweight fine bar plate maximized internal and external fibrillation while minimizing fiber length loss. In conclusion, the lightweight fine bar plate was shown to be more effective in improving the strength properties of paper and reducing energy consumption.

Investigation of Bipolar Plate Forming with Various Die Configurations by Magnetic Pulse Method

Bipolar plates are a major part of fuel cells, which are a clean and recyclable energy source. This study was carried out with two dies for a bipolar plate forming investigation with the magnetic pulse method: a bipolar plate die and a 10-channel die. With the bipolar plate die, the forming of bipolar plates with a Cu110 sheet and a Grade 2 Ti sheet indicated that the bipolar plate die needed optimization for a full replication. The obtained maximum average depth percentage was 86% for a Cu110 sheet, while it was 54% for a Grade 2 Ti sheet in this study. A further increase of the depth percentage is possible but requires a much higher capacitor bank energy. The increase of the capacitor bank energy would result in severe tearing, while the depth percentage increase was little. The primary current and flyer velocity were measured at various capacitor bank energies. With the 10-channel die, the die parameters’ effect on metal sheet forming was investigated with a Cu110 sheet and an SS201 sheet. The draft angle had a significant effect on the replication of the die surface. The full replication was achieved for channels with proper parameters with both a Cu110 sheet and an SS201 sheet. Therefore, the bipolar plate die could be optimized based on the 10-channel die results.

Optimization of geometrical design of clinching tools in flat-clinching

Owing to the importance of geometrical design of clinching tools, the flat-clinching were investigated numerically and experimentally to determine the optimal geometrical parameters in this study. The geometrical parameters in flat-clinching, including punch corner radius, draft angle of the punch, blank holder corner radius, blank holder radius, and punch velocity, were optimized using the orthogonal experimental design simulation method based on the evaluation of interlocking. The simulation results show that the punch corner radius and the blank holder radius have a significant impact on the clinched joint, whereas the draft angle of the punch and blank holder corner radius have little influence on the clinched joint. The simulation results were validated through an experimental setup testing on material aluminum alloy Al5052. The experimental results have a good agreement with the orthogonal experimental design simulation.