Two‐Step Fabrication of Hybrid Composite Using Direct Additively Manufactured PETG Mold/Inner Layer and Vacuum Bag‐Assisted UV ‐Cured PLA ‐Like‐Glass Fiber Composites as an Over‐Mold for PPE Applications

A hybrid manufacturing strategy for protective equipment applications is presented, combining fused deposition modeling (FDM) of polyethylene terephthalate glycol (PETG) with vacuum bag‐assisted UV‐curing of glass fiber‐reinforced, PLA‐like photopolymer over‐molds. X‐ray diffraction confirmed FDM‐induced crystallinity increase in PETG from 23.1% to 28.7%, enhancing substrate rigidity. Flexural modulus increased 38.8% (31.4 ± 0.8 MPa to 42.9 ± 1.9 MPa) with glass fiber reinforcement, though strength decreased from 89.6 ± 4.5 MPa to 65.1 ± 5.9 MPa due to modulus mismatch. Interlaminar shear strength (5.77 ± 1.76 MPa) revealed the PETG/photopolymer interface as the critical weakness, with predominant adhesive failure. This tool‐less, digitally‐driven approach enables rapid customization of geometrically complex composite structures while eliminating energy‐intensive metal molds, establishing a scalable pathway for small‐batch protective component manufacturing.