A laser joining method and device includes a pressure-applying clamping device, which presses a first and a second workpiece against one another at least after the workpieces have been locally plasticized, and a mask having mask structures, which allow laser light to pass only in the region of the bonding contact faces, wherein at least the workpiece facing the laser source is formed by a three-dimensional molded part, which is not planar at least on the first contour side facing the clamping element and/or on the second contour side facing the second workpiece, and wherein the clamping element, with the bearing side thereof for the first workpiece, is adapted to the first contour side of the first workpiece. The mask structures are created on the bearing side of the clamping element facing the first workpiece or on the second contour side of the first workpiece facing the second workpiece.

An assembly (1) for protecting an acoustic device comprises an expanded polytetrafluorethylene (ePTFE) membrane (3) and first and second polymeric substrates (2, 4) disposed on opposing sides (5, 6) of the membrane (3). The first substrate (2) is transmissive for laser light of a predetermined wavelength, and the membrane (3) is joined to the first and second substrates (2, 4) by first and second laser weld joints (9, 10) on the first side (5) of the membrane (3) and the second side (6) of the membrane (3), respectively, that are created in a single laser transmission welding step through the first polymeric substrate (2) towards the second polymeric substrate (4). The first side (5) of the membrane (3) may be at least partially absorbent for the laser light and the second side (6) may be at least partially transmissive for the laser light. This may be achieved by a color gradient from black to white from the first side (5) to the second side (6).

The invention relates to a method for forming a laser-welded connection, in which two parts to be joined (11; 11a, 12; 12a) are connected to one another under the effect of a laser beam (1) in a joining region (30; 30a) to form a weld (2), wherein one part to be joined (11; 11a) consists of a material transparent to laser radiation and the other part to be joined (12; 12a) consists of a material absorbent to laser radiation, and wherein the two parts to be joined (11; 11a, 12; 12a) form a receptacle (25; 25a; 25b) for a component (13; 13a; 13b; 14) separate from the parts to be joined (11; 11a, 12; 12a).

A method of connecting together two unit elements (4, 4) of a fluid transport pipe, each unit pipe element being covered in an outer insulating coating (6, 6) made of a thermoplastic material, with the exception of an end portion that does not have an outer insulating coating. The method includes: a step of welding together two abutting unit pipe elements; a step of positioning an annular sleeve (14) around a cut-back and in part around the outer insulating coatings of the two unit pipe elements, the sleeve being made of a thermoplastic material; a step of fastening the sleeve in sealed manner by weld bonding on the outer insulating coatings; and a step of applying an external pressure on the sleeve to enable it to be deformed elastically and match the shape of the respective end portions of the two unit pipe elements.

The invention provides a method of connecting together two unit elements (4, 4) of a fluid transport pipe, each unit pipe element being made of metal alloy and being covered in an outer insulating coating (6, 6) made of a thermoplastic material, with the exception of an end portion that does not have an outer insulating coating, the method comprising a step of butt-welding together two unit pipe elements at their end portions having no outer insulating coating, a step of mechanically assembling at least two rigid shells (14, 16) made of a thermoplastic material on the end portions of the unit pipe elements not having an outer insulating coating, and a step of keeping the shells sealed against the outer insulating coating of the two unit pipe elements.

Plastic parts are welded in a laser welding system. An infrared laser source in a laser chamber is controlled by a controller using closed-loop feedback control with a corrected feedback signal that is compensated for background infrared radiation in the laser chamber. Prior to the infrared laser source being turned on, the controller senses with the optical sensor an intensity of background infrared radiation in the laser chamber. Once the laser is on, the controller senses with the optical sensor an intensity of infrared laser radiation in the laser chamber. The controller calculates the corrected feedback signal by subtracting the intensity of the background infrared radiation sensed when the infrared laser source was off from the intensity of the infrared laser radiation sensed when the infrared laser source is on.

An example method includes providing a working stack having a first substrate layer, a second substrate layer, and a radiation-absorbing material disposed between the first and second substrate layers. The working stack includes a cavity therein having a designated liquid. A bonding interface is defined between the radiation-absorbing material and at least one of the first substrate layer or the second substrate layer. The bonding interface has a film of the designated liquid. The method also includes directing radiation onto the bonding interface to form a perimeter seal. The perimeter seal separates the cavity from an outer area of the bonding interface. The method also includes directing the radiation onto the outer area of the bonding interface to secure the first and second substrate layers together. The perimeter seal impedes an ingress of bubbles from the outer area into the cavity as the radiation is directed onto the outer area.

A rubber member for laser bonding of the present invention containing a rubber ingredient and silica, wherein the silica has an average particle size of more than 50 nm and 120 nm or less, and the amount of the silica is 10 parts by mass to 50 parts by mass based on 100 parts by mass of the rubber ingredient, the rubber member has a laser light transmittance of 30% or more, provided that the laser light transmittance is a transmittance when the rubber member has a thickness of 2 mm and is irradiated with laser light having a wavelength of 808 nm. The silica preferably includes silica having an average particle size of more than 50 nm and 120 nm or less and silica having an average particle size of 5 nm to 50 nm, and the amount of the silica having an average particle size of more than 50 nm and 120 nm or less is 10 parts by mass to 50 parts by mass based on 100 parts by mass of the rubber ingredient and the amount of the silica having an average particle size of 5 nm to 50 nm is 10 parts by mass to 50 parts by mass based on 100 parts by mass of the rubber ingredient.

A method for producing a filter element for filtering fluids, such as hydraulic fluids, lubricants or fuels, includes the following steps: a) providing at least one section of a filter mat web (14) made of one or more layers of at least one filter medium; b) connecting the ends of the at least one section to form an annular body (12) and placing that annular body onto a support pipe (16); c) wrapping at least one cutout of a film web (8) around the outside of the annular body (12) located on the support pipe (16) and d) placing end areas (24) of the at least one cutout of the film web (8) one on top of the other and connecting the overlapping end areas (24).

A laser welding system is directed to simultaneously joining respective layers of a first bag and a second bag. The system includes a first film layer adjacent to a second film layer for forming the first bag, and a third film layer adjacent to a fourth film layer for forming the second bag, each layer of the plurality of film layers being made of a thermoplastic material that absorbs laser radiation having a wavelength of about 2 microns. A non-absorbing carrier film layer is positioned between the second film layer and the third film layer, the non-absorbing carrier film layer being made of a material that transmits substantially all energy of the laser radiation. A laser source applies the laser radiation toward portions of the plurality of film layers to be joined, forming the first bag generally simultaneously with the second bag.