A method for joining two objects by anchoring an insert portion provided on one of the objects in an opening provided on the other one of the objects. The anchorage is achieved by liquefaction of a thermoplastic material and interpenetration of the liquefied material and a penetrable material, the two materials being arranged on opposite surfaces of the insert portion and the wall of the opening. Before such liquefaction and interpenetration, an interference fit is established in which such opposite surfaces are pressed against each other, and, for the anchoring, mechanical vibration energy and possibly a shearing force are applied, wherein the shearing force puts a shear stress on the interference fit.

In order, in the case of a strapping apparatus for strapping articles with a strapping band, having a base plate (4) which is provided for arranging on an article, having a tensioning device (6) with which a band tension can be applied to the strapping band, the tensioning device (6) being provided for this purpose with an actuable tensioning tool which can be brought into and out of contact with the band, having a sealing device with which, by contact with the band, two band layers can be permanently connected to each other by forming a seal between the two band layers, being provided with a clamping device which has at least one clamp with two interacting clamping elements for clamping the band between the clamping elements, and being provided with at least one actuating element with which a magnitude of a tensioning force which can be applied to the strapping band or a magnitude which is dependent on the tensioning force can be set, to improve the strength of friction-welded band strapping seals produced by the strapping apparatus, it is proposed that a cooling time period for the seal, during which the strapping apparatus does not release the strapping band after the end of a welding time, is variable depending on the variably adjustable tensioning force or a magnitude which is dependent thereon.

The present invention relates to an apparatus and method for joining a longitudinal seam in a tube, to an apparatus and method of joining a longitudinal seam in a tube in a borehole, to an apparatus and method of repairing a tube and to a pig. In an aspect an apparatus is provided for joining a longitudinal seam in a tube. The apparatus (200) includes a spool (202) for progressively unwinding a coiled member (10) into an extended form (12). The member (10) transitions from a flat form when coiled (11) to a slit tube form when extended (12), in which form the member is resiliently biased. A joining device (214) is positioned downstream of the spool arranged to provide energy to a portion of the member in its extended form to cause heating so as to progressively join together the longitudinal edges of the slit tube as the member passes the joining device. A longitudinal seam (20) is thereby formed in the tube.

A vibration welding groove system may include a first component having a joining surface with a groove region, where the groove region comprises a groove formed in the joining surface. The first component includes a base region lacking the groove in the joining surface and a transition region located between the groove region and the base region. The transition region has a tapering of the groove to provide a smooth transition from the groove region to the base region. The vibration welding groove system may further include a second component having a weld leg extending from a main body, where the groove of the first component comprises a shape configured to nudge the weld leg towards a center of the groove during joining of the first component with the second component.

The present invention relates to a method for welding two polyamide plastics using a primer, the primer containing at least one polymer synthesized from at least one maleic anhydride or maleic anhydride derivative. The invention also relates to correspondingly welded products.

The invention relates to a method for welding two different polyolefin plastics using a primer, said primer containing at least one maleic anhydride graft polyolefin polymer. The invention also relates to correspondingly welded products.

The invention relates to a method for welding a polyolefin plastic and a plastic consisting of a polymer with at least one aromatic unit in the polymer main chain, using a primer which contains at least one polymer built from at least one monomer with at least one double bond. The invention also relates to correspondingly welded products.

The invention relates to a method for bonding two different plastics using a primer. The two plastics which are to be joined to each other have a weighted quadratic distance between the Hansen parameter (R.sub.a).sup.2 of more 22 MPa and the primer contains a polymer which has a weighted quadratic distance between the Hansen parameter (R.sub.a).sup.2 of less than 22 MPa to both of the plastics which are to be joined. The invention also relates to correspondingly bonded products.

The invention relates to a method for welding a polyamide plastic and a poly(meth)acrylateparticularly a polymethyl methacrylateplastic using a primer, said primer containing at least one copolymer synthesised from at least one styrene or styrene derivative and at least one maleic anhydride or maleic anhydride derivative. The invention also relates to correspondingly welded products.

The invention relates to a method for welding a polyolefin plastic and a plastic based on at least one polymer containing carbonyl groups, using a primer which contains, in relation to the proportion of polymer in said primer, at least 20 wt. % of a polymer that comprises maleic anhydride or maleic anhydride derivative units. The invention also relates to correspondingly welded products.