Slitting process optimization

• Main Author: Willy Perdana Tanuwijaya
• Other Authors: Lee Ka Man, Carman
• Format: Theses and Dissertations
• Language: English
• Published: 2014
• Subjects: DRNTU::Engineering::Manufacturing
• Online Access: http://hdl.handle.net/10356/60684
• Institution: Nanyang Technological University

The incorrect slitting is the defect waste in slitting process which does not meet the single pack width and crease-to-edge width requirements. It is the highest contributor to the overall defect waste in slitting process at Company X Jurong (CXJ). To address this problem, the key input and output variables were identified. The inputs are the tension settings (both at main pull-unit and re-winder), line speed and knives’ positioning, and the output is crease-to-edge width. The objectives are to optimize the inputs and to achieve a centered process by a proper calibration of knives’ positioning. The Design of Experiments (DoE) was conducted to study the significance of tension and line speed towards crease-to-edge width variance for 200 mL slim pack size. The experiments were conducted for two fixed re-winder tension settings, i.e. 55% and 85%. The optimum point is found at pull-unit web tension of 1600 N and line speed of 700 m/min. This results in standard deviation of σ55%, min = 0.081 mm and σ85%, min = 0.09 mm, which is about half of each maximum variation values obtained within the specified range. However, the process is currently off-centered. Therefore, a proper training for detecting any mean shift happening in the process to the operators utilizing the digital camera measurement system is recommended.