Performance Evaluation of Bar Plates without a Draft Angle to Improve Refining Efficiency

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

“…The sharp corners of the patterns have led to local structural weaknesses such as shrinkage, cracks, tears, and draws (Kay 2002). Refiner plates with the draft angle are considered to minimize the open area of the stock flow zone between bars, stock throughput, and plate life (J&L Fiber Services 2006; AFT catalog 2017; Lee et al 2019). In contrast, refiner plates with zero-degree draft angles can maximize the area of the stock flow path, plate life, hydraulic capacity, and bar edge sharpness (Ratnieks 2007;Robinson et al 2010).…”

“…The most used technology for manufacturing refiner plates is the original sand casting technology. This technology must give a draft angle of 3 to 5° to protect the patterns in the manufacturing process, thereby limiting the hydraulic capacity on low intensity pattern designs (J&L Fiber Services 2006;Lee et al 2019). A lost-wax casting technology could be used to manufacture bar plates with no draft angle (Lee et al 2019).…”

“…This technology must give a draft angle of 3 to 5° to protect the patterns in the manufacturing process, thereby limiting the hydraulic capacity on low intensity pattern designs (J&L Fiber Services 2006;Lee et al 2019). A lost-wax casting technology could be used to manufacture bar plates with no draft angle (Lee et al 2019). However, it is not easy to reduce the plate weight because there are limitations to the selection of the metal alloy to be used (J&L Fiber Services 2006).…”