Leister Process Technologies

Leister Technologies Ag

Jie-Wei Chen

Adolf Markus Niederberger

Alexander Greber

Christiane Leister

Albert Hirt

A method and device allows dynamic mask welding with online position adjustment in the high-speed welding of structured and endless plastic films. By a transparent driven mask roller provided with masks being arranged in a passive pressure roller surrounding the mask roller, detection can take place optically, and the mask roller and consequently the mask are synchronized with the film speed. Adjustment is detached from a film transport mechanism and does not influence the welding process and in this case, above all, the speed. High film transport speeds in the range of up to 1000 mm per second can be employed.

Method and device for the mask welding of moving plastic films by lasers

A method and apparatus for simultaneously heating materials, in particular for welding plastic components, having an arbitrary shape of a flat heating contour by laser radiation is provided. The apparatus has, an appropriate optical arrangement that is used to convert a laser beam into an annular laser beam and focus it onto the end wall of a light-guiding tube and couple it in. At an exit end, the tube is deformed in accordance with the desired heating contour such that the emerging laser beam has this heating contour.

Method and apparatus for simultaneously heating materials

A method for joining workpieces by welding with laser light, in which a plurality of workpieces are arranged between a lower pressure plate and a translucent upper pressure plate on a multiplicity of supporting segments movable in a vertical direction, whereby the workpieces are subsequently exposed through the upper pressure plate to a laser beam. The workpieces on the supporting are pressed together and towards the upper plate with a prescribed contact pressure, the spacing of the supporting segments from the upper pressure plate being set variably and independently from each other. A device for joining workpieces by welding with laser light, comprises at least one upper pressure plate of transparent material and a lower pressure plate with multiplicity supporting segments for the workpieces. The supporting segments are arranged side by side on the lower plate and are movable in a vertical direction by compressed air and can be set independently from each other.

Method and apparatus for processing articles with a laser beam

A method for joining workpieces made from plastic, the upper workpiece, facing a laser source, consisting of a material transparent to the laser beam, and the lower workpiece consisting of a material absorbent to the laser beam, such that the mutually bordering contact surfaces for the two workpieces melt and are joined to one another under pressure during a subsequent cooling, the guiding of the laser beam onto the site to be joined, and the mechanical compression of the workpieces being carried out simultaneously by a machining head. The corresponding device comprises a machining head with focussing devices for the laser beam onto the contact surface, and pressure-exerting devices for compressing the workpieces. A rotatably mounted glass ball or roller is particularly suitable as pressure-exerting device. The invention permits welding quality to be assured in conjunction with flexibility of the welding operation without expensive and complicated damping balls.

Method and device for joining workpieces made from plastic in three-dimensional form by means of a laser beam

Process and apparatus for joining endless polymer materials by means of the transillumination technique. According to the invention, in order to be joined, the endless materials are guided through two contrarotating rollers that press against each other. The first roller consists of a material that is transparent to laser beams and is tubular. The second roller is formed from a material that can be deformed easily at the surface, so that its surface can adapt to the shape of the first roller. Devices for producing a laser beam at the contact surface between the materials to be joined are arranged in the first roller. In this case, the beam is formed as a linear laser beam longitudinally with respect to the direction of movement of the materials so that during the passage, continuous heating of the material up to the melting point is achieved, without an excessively high laser output having to be provided. By means of the process and the apparatus, continuous joining is possible at high speed.

Process and apparatus for joining polymer materials at a high welding speed

A process and a device for joining or separating various workpieces, in particular made of plastic or plastic and other materials, by means of curtain-like laser beams. To join workpieces in a particular joining area of the contact surface, a mask, made of a laser-impermeable material, is arranged between the laser source and the workpieces to be joined. The laser beam and the mask are moved relative to each other. To generate high energy density in the joining area, laser beams of at least two diode lasers are brought together, and subsequently, differing laser line lengths are generated by means of a zoom optics arrangement.

device for heating at least two elements by means of laser beams of high energy density

A method and a device for laser joining of plastics or for joining plastics to other materials, which are brought into contact with pressure, with the workpiece closest to the laser beam source being largely transparent for the laser beam, and the second workpiece being as absorbent as possible. By producing a laser beam shaped in the form of a line on the contact surface between the workpieces and by a relative movement of the laser beam relative to the workpieces, designed according to the desired joint seam structure, the workpieces are bonded together accurately only in the desired joining areas. This permits a highly accurate bonding with the smallest possible joint seam distances, so that even parts for micro-systems engineering can also be produced with a short cycle time.

Laser joining method and a device for joining different workpieces made of plastic or joining plastic to other materials

A process and a device for joining or separating various workpieces, in particular made of plastic or plastic and other materials, by means of curtain-like laser beams. To join workpieces in a particular joining area of the contact surface, a mask, made of a laser-impermeable material, is arranged between the laser source and the workpieces to be joined. The laser beam and the mask are moved relative to each other. To generate high energy density in the joining area, laser beams of at least two diode lasers are brought together, and subsequently, differing laser line lengths are generated by means of a zoom optics arrangement. Via a beam splitter, a first laser beam aligned perpendicularly to the surface of the mask, is joined by at least one secondary laser beam arranged perpendicularly to the first laser beam, and the resulting laser beam is directed onto the mask.

Growing community of inventors

Alpnach Dorf, Switzerland

Jie-Wei Chen