The present work investigated in detail the effects of stirring rate, temperature, and the feed flow rate of the reducing agent on the properties of functionalized silver nanoparticles produced in a semi-batch reactor. In addition, a specific formulation was tested in chemical reactors with different volumes to demonstrate the scalability of the process. The colloids were characterized using UV-Vis spectrophotometry, transmission electron microscopy, X-ray diffraction, and zeta potential. The scale up of the process was successfully performed, producing similar results at larger scales to those obtained in the small scale. Standardized antibacterial assays showed that fabric and polymer samples functionalized with the produced silver colloids presented outstanding antibacterial activity. These findings demonstrated that silver nanoparticles with specific properties and promising antibacterial applications can be rapidly produced through suitable tuning of the process parameters regardless the scale of production.