Design and Experimental Validation of a Programmable Pressure Pneumatic Knife CNC Platform for Flexible Sheet Cutting

This study presents a programmable pressure pneumatic knife CNC platform for the fabrication and experimental investigation of flexible sheet materials. The platform enables independent control of blade-loading pressure, feed rate, and toolpath motion, allowing pressure–feed rate operating windows for mechanical knife cutting to be established. Paper and vinyl sheets are evaluated using square and straight-line cutting patterns, with cutting quality classified into four regimes: clean cut, skimming, tearing, and crushing. The results demonstrate that insufficient pressure causes unstable blade–material contact, resulting in skimming or no-touch behavior, whereas excessive pressure promotes tearing. Paper attains a 99% clean cut rate at 1 bar and 9000 mm min−1 during square cutting, while vinyl exhibits 100% clean cuts across 3000 mm min−1 to 9000 mm min−1 at 3 bar. Straight-line cutting achieves clean cut rates of 98% for paper and 97% for vinyl at 2 bar and 7000 mm min−1. These findings support the effectiveness of programmable pressure mechanical knife cutting for repeatable fabrication of flexible sheet materials.