Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE SLS-printed PA12 specimens (untreated or VaporFuse Surface–treated) were evaluated by PAA sanitization (400 ppm; L. monocytogenes, E. coli, S. aureus) and ISO 3452–based penetrant testing, showing > 99.999% bacterial reduction on both surfaces and improved surface continuity after VFS.

ABSTRACT
This study investigates the surface quality and hygienic suitability of nylon 12 3D-printed components for food industry applications. The research aimed to determine whether surface treatment influences cleanability and disinfection efficiency. Samples of food-grade nylon 12 (PA12) were produced via Selective Laser Sintering (SLS). Half of the samples received VaporFuse Surface (VFS) posttreatment to reduce surface roughness while the other ones did not. Microbiological tests assessed the sanitization efficiency of peracetic acid (PAA) at 400 ppm against Listeria monocytogenes, Staphylococcus aureus, and Escherichia coli on both surfaces. Comparable log reductions (~6.5–6.8) were achieved for both untreated and treated samples, indicating that PAA performance was not affected by surface condition under the tested parameters. To complement these results, a nondestructive surface inspection adapted from ISO 3452 series evaluated pigment retention and surface continuity as indirect indicators of cleanability. The results showed treated samples exhibited smoother surfaces and reduced roughness, improving cleanability and indicating a higher potential for hygienic use. These findings suggest that microbiological results alone may not fully capture cleanability performance, and that surface quality assessment provides critical complementary insight when evaluating 3D-printed components for food-contact applications.