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.

A connector is formed by fixing two or more connector parts each made from a resin to each other by press fitting or with an adhesive. At least one weld part regulating thermal deformation between the connector parts is formed in a boundary portion between the adjoining connector parts.

The present invention relates to a process for laminating a first substrate, which comprises a thermoplastic polymer material surface, and wherein the first substrate preferably is a thermoplastic polymer film, to a second substrate, wherein the second substrate preferably is a non-woven or woven fabric, wherein the thermoplastic polymer material surface is activated by irradiation with a laser beam prior to laminating the two substrates to each other as well as a device for carrying out such a process.

A laser welding method and system for joining portions of first and second workpieces of thermoplastic material that is partially permeable to a laser beam but absorbs radiation from the laser beam. The first and second workpieces, which are made of material that absorbs radiation from a laser beam, are clamped together. A mask is placed on a first surface of the first workpiece, the first surface being opposite the surface engaging the second workpiece. The mask is impermeable to a laser beam and forms a slot for passing a laser beam to the portion of the first surface of the upper workpiece exposed by the slot, so that heating and melting of the material of the workpieces is limited to the width of the slot. A laser beam is directed onto the slot and moved in a manner to illuminate the slot to melt and join the workpieces.

A machine and method for making bags is described and includes a web traveling from an input section to a rotary drum, to an output section. The rotary drum includes at least one seal bar, having a single sealing zone, and a weakening zone disposed within the single sealing zone. The single sealing zone may be a heated perforator, includes a heating wire. The heating wire may be an NiCr wire stitched into the heater, and be disposed on a cap or on the seal bar. The weakening zone may create a line of weakness that is uniform or varies in intensity. The sealing zone may include temperature zones, cartridge heaters, cooling air, or heated air, or a source of ultrasonic, microwave or radiative energy.