Described herein is a process for producing a molded body which encloses a cavity, by welding two partial bodies. Also described herein is a die with which the process of producing the molded body can be carried out. Also described herein is a molded body which can be obtained by the process.

An ultrasonic sealing device including a sonotrode for sealing a packaging material, including a piezoelectric transducer to generate ultrasonic acoustic vibrations for the sealing, a housing, a power circuit connected to the piezoelectric transducer. The power circuit is enclosed in the housing, and an absorbent arranged in the housing to absorb moisture in an atmosphere therein to lower humidity. A method of controlling humidity in an ultrasonic sealing device is also described.

An ultrasonic sealing device including a sonotrode for sealing a packaging material, including a piezoelectric transducer to generate ultrasonic acoustic vibrations for the sealing, a housing, a power circuit connected to the piezoelectric transducer. The power circuit is enclosed in the housing, and an absorbent arranged in the housing to absorb moisture in an atmosphere therein to lower humidity. A method of controlling humidity in an ultrasonic sealing device is also described.

A device for thermally welding workpieces including a heating element and a shielding gas supply is provided. The device includes a heating plate consisting of a thermal insulating material in which a groove is formed, said groove includes a heating element, relative to which a surface of a workpiece to be welded is positioned in close proximity to the heating element. A feed channel for a shielding gas is formed in the heating plate and communicates with the groove via at least one through-channel, and the feed channel for supplying shielding gas can be connected to a shielding gas source via a feed line and a valve. The device may further include an assembly for welding a first and a second workpiece, said assembly includes a first and second movement device for moving the workpieces towards one another.

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 first sealing zone, and an adjacent weakening zone. The weakening zone may be a heated perforator, includes a heating wire, or be disposed to create an auxiliary sealed area. The heating wire can have connected thereto, a source of power that is an adjustable voltage or magnitude, and/or pulsed, and/or a feedback loop. The heating wire ay be an NiCr wire and make intermittent contact with the web and be disposed in an insert. The weakening zone may create a line of weakness that is uniform or varies in intensity, is a separating zone, or includes a heat film, a toothed blade, a row of pins, a source of air, or a source of vacuum. The sealing zones ma include temperature zones, cartridge heaters, cooling air, or hated air, or a source of ultrasonic, microwave or radiative energy.

A method of joining overlapping thermoplastic geomembrane components in which a first thermoplastic geomembrane component and a second thermoplastic geomembrane component are positioned in overlapping relationship between a pair of complementary molding surfaces, with one or more of the complementary molding surfaces being defined by an electrically conductive metal susceptor. Heat is generated in the metal susceptor and transferred by thermal conduction from the metal susceptor to overlapping portions of the first and second thermoplastic geomembrane components to locally melt and coalesce a portion or more of the thermoplastic material of the first thermoplastic geomembrane component and a portion or more of the thermoplastic material of the second thermoplastic geomembrane component. The molten thermoplastic material of the first and second thermoplastic geomembrane components forms a zone of coalesced thermoplastic material that, upon cooling, forms a solid weld joint.

A method of joining overlapping thermoplastic roofing membrane components in which a first thermoplastic roofing membrane component and a second roofing membrane component are positioned in overlapping relationship between a pair of complementary molding surfaces. Heat is generated in a metal substrate and transferred by thermal conduction from the metal substrate to overlapping portions of the first and second thermoplastic roofing membrane components to locally melt and coalesce a portion or more of the thermoplastic material of the first thermoplastic roofing membrane component and a portion or more of the thermoplastic material of the second thermoplastic roofing membrane component. The molten thermoplastic material of the first and second thermoplastic roofing membrane components forms a zone of coalesced thermoplastic material that, upon cooling, forms a solid weld joint.

A method of joining overlapping thermoplastic geomembrane components in which a first thermoplastic geomembrane component and a second thermoplastic geomembrane component are positioned in overlapping relationship between a pair of complementary molding surfaces, with one or more of the complementary molding surfaces being defined by an electrically conductive metal susceptor. Heat is generated in the metal susceptor and transferred by thermal conduction from the metal susceptor to overlapping portions of the first and second thermoplastic geomembrane components to locally melt and coalesce a portion or more of the thermoplastic material of the first thermoplastic geomembrane component and a portion or more of the thermoplastic material of the second thermoplastic geomembrane component. The molten thermoplastic material of the first and second thermoplastic geomembrane components forms a zone of coalesced thermoplastic material that, upon cooling, forms a solid weld joint.

Described is a heated gaseous welder system and associated methods of welding plastic with the heated gaseous welder system. The heated gaseous welder system includes a welding tool and a welder control unit. The welder control unit includes a gaseous control system and a heater control system. The gaseous control system is configured to selectively supply a gas to the welding tool and control at least one characteristic of the gas supplied to the welding tool. The heater control system is configured to selectively control power supplied to the welding tool.

An impulse welding bar (10) for welding plastics films is provided with a detachable non-stick coating (20) which is held on lateral flanks (24) of the impulse welding bar (10). In order to facilitate the replacement of a worn non-stick coating (20), retaining elements (22) are provided which are made of two or more parts and which act in a form-fitting manner in order to detachably fasten the non-stick coating (20) to both flanks (24) of the impulse welding bar (10), wherein first parts (26) of the retaining elements (22) are arranged on the flanks (24) of the impulse welding bar (10) and second parts (36) of the retaining elements (22) are arranged on the non-stick coating (20).