# 3D Printed Mask Frames Improve the Inward Protection Efficiency of a Cloth Mask

> Research article (ACS ES&T Engineering, 2021) · cited 12× · AI/ML

**Wikidata**: [openalex:W3158991372](https://www.wikidata.org/wiki/openalex:W3158991372)  
**Source**: https://4ort.xyz/entity/3d-printed-mask-frames-improve-the-inward-protection-efficiency-of-a-cloth-mask