A method, apparatus, and system are provided to monitor and characterize the dynamics of a phase change region (PCR) created during laser welding, specifically keyhole welding, and other material modification processes, using low-coherence interferometry. By directing a measurement beam to multiple locations within and overlapping with the PCR, the system, apparatus, and method are used to determine, in real time, spatial and temporal characteristics of the weld such as keyhole depth, length, width, shape and whether the keyhole is unstable, closes or collapses. This information is important in determining the quality and material properties of a completed finished weld. It can also be used with feedback to modify the material modification process in real time.

A method, apparatus, and system are provided to monitor and characterize the dynamics of a phase change region (PCR) created during laser welding, specifically keyhole welding, and other material modification processes, using low-coherence interferometry. By directing a measurement beam to multiple locations within and overlapping with the PCR, the system, apparatus, and method are used to determine, in real time, spatial and temporal characteristics of the weld such as keyhole depth, length, width, shape and whether the keyhole is unstable, closes or collapses. This information is important in determining the quality and material properties of a completed finished weld. It can also be used with feedback to modify the material modification process in real time.

A hydro-formed film includes a polymeric web having a first substantially planar surface and a second substantially planar surface opposite the first substantially planar surface, and a plurality of three-dimensional micro-apertures extending from the first substantially planar surface. The plurality of three-dimensional micro-apertures have a mesh count in a range of about 40 to about 75 apertures per linear inch. The hydro-formed film has a Compression Sensor Point (CSP) count of at least about 80.

A hydro-formed film includes a polymeric web having a first substantially planar surface and a second substantially planar surface opposite the first substantially planar surface, and a plurality of three-dimensional micro-apertures extending from the first substantially planar surface. The plurality of three-dimensional micro-apertures have a mesh count in a range of about 40 to about 75 apertures per linear inch. The hydro-formed film has a Compression Sensor Point (CSP) count of at least about 80.

A method of processing a polymeric web includes providing a forming screen configured for supporting and moving with the web in a machine direction. The forming screen has a plurality of elliptical screen openings, each having a major axis perpendicular to the machine direction and a minor axis parallel to the machine direction. The method includes continuously depositing the web onto the forming screen and passing the web and forming screen through a water stream having a pressure level sufficient to cause the web to be forced into the screen openings, thereby forming protrusions extending from the planar surface of the web. Each protrusion has an apex, an opening at the apex, and an elliptical cross-section parallel to the planar surface of the web. The elliptical cross-section has a protrusion axis ratio that may be selected so as to produce a desired protrusion axis ratio.

A method of processing a polymeric web includes providing a forming screen configured for supporting and moving with the web in a machine direction. The forming screen has a plurality of elliptical screen openings, each having a major axis perpendicular to the machine direction and a minor axis parallel to the machine direction. The method includes continuously depositing the web onto the forming screen and passing the web and forming screen through a water stream having a pressure level sufficient to cause the web to be forced into the screen openings, thereby forming protrusions extending from the planar surface of the web. Each protrusion has an apex, an opening at the apex, and an elliptical cross-section parallel to the planar surface of the web. The elliptical cross-section has a protrusion axis ratio that may be selected so as to produce a desired protrusion axis ratio.

An absorbent foam having a first surface and a second surface is disclosed. The foam has one or more etched voids. The one or more etched voids have an irregular inner surface.

A method of etching an absorbent foam. The method includes providing an absorbent foam; providing a fluid etching process having one or more fluid jets, a carrier belt, and a stencil having one or more open apertures, wherein the carrier belt carries an absorbent foam under the one or more fluid jets, wherein the stencil is between the fluid jets and the absorbent foam; expelling a fluid from the fluid jets through the open apertures of the stencil; and etching the absorbent foam to create an etched foam having voids and one or more pieces of voided foam.

A method for fabricating an airfoil includes forming a diffuser section in an exterior surface of the airfoil. The diffuser section is defined by at least an outer surface and an inner surface that converge at a stop surface. The method also includes positioning a drilling element of a drilling device on the stop surface. The method further includes orienting the drilling element at a first angle relative to the exterior surface. The method also includes forming, using the drilling element, a cooling channel extending through the airfoil from the stop surface to an interior surface, thereby forming the cooling channel at substantially the first angle.

A method for fabricating an airfoil includes forming a diffuser section in an exterior surface of the airfoil. The diffuser section is defined by at least an outer surface and an inner surface that converge at a stop surface. The method also includes positioning a drilling element of a drilling device on the stop surface. The method further includes orienting the drilling element at a first angle relative to the exterior surface. The method also includes forming, using the drilling element, a cooling channel extending through the airfoil from the stop surface to an interior surface, thereby forming the cooling channel at substantially the first angle.