Abstract: Various implementations include a fused filament fabrication print head system that includes a nozzle, a heating block, and a cooling element. The nozzle defines a nozzle opening and a filament flow path and is configured to deposit a filament through the nozzle opening. The heating block is coupled to the nozzle such that the filament flow path extends through the heating block. The heating block includes a heating element. The cooling element is spaced apart from the heating block along the filament flow path and is configured to provide localized cooling to a portion of the filament at a location along the filament flow path prior to the heating block. The localized cooling provided by the cooling element preserves the stiffness of the filament and ensures sufficient back pressure to push the filament through the heating block and nozzle opening.

Abstract: An article of manufacture for providing a mask fixer to prevent air leakage at the edges is disclosed. The mask fixer includes a face piece and one or more components coupled to the face piece. The face piece includes a central aperture, an exterior surface, and an interior surface. Features, such as a nasal reinforcer, a flange, and/or a sealing loop, may be added to different parts of the face piece to form different embodiments of the mask fixer for different applications. In some embodiments, the mask fixer is used by releasably wearing it outside or inside a surgical or cloth mask to reduce air leakage at the edges. In other embodiments, the mask fixer includes a flange around the central aperture of the face piece. A surgical mask, a cloth mask or a filter is wrapped and fixed around this flange using a band or a snapping mechanism. As such, the mask fixer is integrated with a filter or a surgical or cloth mask to form a new face mask. This new face mask would diminish air leakage at its edges.