TRIZ-Assisted Structural Design of a Polishing Machine for Aluminum Strip Straightening Rolls

Straightening rolls used in aluminum strip production are progressively contaminated by metal particles and fine debris that adhere to their surfaces. Periodic polishing is therefore required to restore the surface condition of the rolls while avoiding excessive material removal or surface damage. This study developed an automated polishing machine for aluminum strip straightening rolls using the Theory of Inventive Problem Solving (TRIZ) as a systematic engineering-design framework. Two engineering problems were considered: achieving effective contaminant removal without degrading the roll surface and improving loading and unloading productivity without introducing excessive device complexity. The problems were formalized using TRIZ engineering parameters and a contradiction matrix, after which candidate inventive principles were screened according to the physical requirements of the polishing process. The contradiction matrix was therefore used as a candidate-generation tool and engineering screening as the selection criterion. Based on the resulting design requirements, the machine was configured with an abrasive-belt feed mechanism, a lifting mechanism, and an automated loading and unloading mechanism. A programmable logic controller, servo and stepper drives, and an abrasive-belt system were integrated to coordinate workpiece positioning and polishing. A physical prototype was fabricated and evaluated using a two-group comparative test against manual polishing. Surface roughness was measured at three axial positions using a Surftest SJ-210 portable surface roughness tester. In this workshop-scale comparison of three rolls per method, machine-polished rolls exhibited lower mean Ra values and markedly smaller scatter than manually polished rolls, with 0.075 ± 0.004 μm compared with 0.951 ± 0.179 μm. Workshop records indicate an increase in polishing throughput from approximately 55 to 165 rolls/month. All nine machine-polished measurements satisfied the workshop acceptance criterion of Ra ≤ 0.6 μm, whereas all nine manually polished measurements exceeded it. These observations support the engineering feasibility of the proposed machine architecture under the investigated conditions.