A waveguide for plastic welding has an entry end, an exit end as well as a first and a second inner face arranged between the entry end and the exit end, which are arranged opposite to each other and by means of which laser light can be reflected. A first distance between the entry end and the exit end defines a length of the waveguide and a second distance between the first and the second inner face defines a thickness of the waveguide. The exit end may be arranged opposite to the entry end and a central plane of the waveguide may extend centrally from the entry end to the exit end. The first inner face comprises a continuously curved, concave shape so that a third distance between the first inner face and the central plane varies continuously from the entry end in the direction of the exit end.

The invention relates to a method for welding a polyolefin plastic and a plastic using a primer, said primer containing at least one maleic anhydride containing polymer and at least one polyester. The invention also relates to correspondingly bonded products.

A method for sensing intensity of laser light in a simultaneous laser welding system includes placing a smart part in a weld area. The smart part includes at least a laser light intensity sensor for sensing laser light directed at it. Laser light intensity is sensed by the laser light intensity sensor of the smart part which provides an output signal indicative thereof to a controller.

A narrow waveguide homogenizes laser light traveling from a laser light source of a laser bank through a plurality of laser delivery bundles that include at least a fiber optic bundle leg to weld a plurality of work pieces along a weld line that is narrower than the width of the fiber optic bundle leg. The narrow waveguide has a portion associated with each fiber optic bundle leg that is narrower than the fiber optic bundle leg with which that portion of the waveguide is associated. A reflective bounce plane diverts laser light of the fiber optic bundle leg that does not travel through the narrow waveguide.

In order to provide a method for heating an object (102) that is simple to perform and makes it possible to heat an object (102) efficiently and reliably, it is proposed that the method should include the following: providing an object (102) to be heated; applying at least one energy beam (108, 109) to the object (102) to be heated, wherein at least one energy beam (108) is guided over the object (102) to be heated multiple times, along a predetermined intended heating path (114), and this heats the object (102) along the intended heating path (114); determining a temperature distribution over the intended heating path (114), for identifying one or more deviation points (120) at which an actual local temperature differs from an expected and/or calculated temperature; changing and/or supplementing the application of at least one energy beam (108, 109) in order to compensate for the temperature difference at one or more deviation points (120).

A welding process includes inserting two work pieces inside a sealable container. Placing the container with the two work pieces inside into a welding device and welding the two members together while inside the container.

A curved and one-sidedly open waveguide for plastic welding, especially for laser transmission welding, includes a first reflecting element having a reflecting surface by means of which laser light can be reflected. The reflecting surface defines a receiving end at which laser light from a laser light source, in particular a light guide or a plurality of light guides, is receivable, and an output end at which laser light is directable into a laser light transmitting work piece. The reflecting surface is defined by a curve between the receiving end and the output end so that the reflecting surface of the first reflecting element has a continuously curved concave shape when viewed in cross-section. Further, the first reflecting element is not opposed by a second reflecting element so that the waveguide is open in the direction normal to the reflecting surface.

Sensors incorporated within a laser channel detect laser light upconverted by a dopant. The dopant is located after a delivery end of a laser delivery optical fiber and upconverts laser light that has traveled from a laser light source from a laser bank through one of a plurality of laser channels through to a location after the delivery end of a laser delivery optical fiber. In some embodiments, the dopant is positioned at the delivery end of the laser delivery optical fiber. In other embodiments, the dopant is positioned within a dummy part or on a surface of at least a work piece.

A laser welding apparatus is provides that includes: a support member including a heat generation portion which has a size that is limited to correspond to a size of a welding area of a plurality of plastic components and is made from a material that absorbs a laser beam and generates heat, and which generates heat of a temperature that is equal to or greater than a melting temperature of the plastic components; a laser beam irradiation unit for converging a laser beam to be transmitted through the plurality of plastic components, and irradiating the laser beam toward the heat generation portion through the plurality of plastic components; and a welding controller for causing a laser beam to be irradiated at the heat generation portion using the laser beam irradiation unit to thereby cause the heat generation portion to generate heat, and welding abutting faces of a welding area of the plurality of plastic components with heat that is generated.

Sensors incorporated within a laser bank detect light emitted by light sources that is directed into and travels through a delivery end of an associated laser delivery optical fiber. The light sources may be positioned between downstream of the delivery end of the associated laser delivery optical fiber and a lower tooling. In some embodiments, the light source is incorporated within a waveguide. In other embodiments, the light source is positioned within a dummy part.