A method for welding at least two parts including a thermoplastic material and having respective surfaces to be welded, including: inserting an insert between the surfaces to be welded of the two parts; generating heat via the insert; wherein the insert moves in relation to the parts to be welded in a welding direction. Also, an installation adapted for implementation of this method.

A method of joining together liner sections within a polymer-lined pipe energises an induction coil inside the pipe to spot-heat part of a circumferential interface between the liner sections. This melts and fuses the polymer material locally. The induction coil is then moved along the interface to heat other parts of the interface successively above the melting temperature. An apparatus for performing the method has a power supply for energising the induction coil and a drive system for moving the energised induction coil relative to a body of the apparatus. The apparatus may be configured as a carriage that is movable along the pipe.

Applied power as a function of time is ramped up at the onset of an RF welding process in a manner that is predetermined to match source and load impedance as reflected by maximized forward power during at least the majority of the welding process. The ramp-up portion takes the form of a non-linear curve, such as an S-shaped curve, as opposed to one or more discrete steps. The applied power may then be maintained at or near that maximum required value at least a majority of the remainder of the heating portion of the welding process. The shape of the non-linear ramp-up portion of the applied power curve may be predetermined using, for example, virtual motor control using applied power as a virtual axis.

A process for packaging a product arranged on a support comprising unrolling a film, moving the film to a packaging assembly defining at its inside a packaging chamber, progressively moving a number of supports inside the packaging chamber of the packaging assembly, closing the packaging chamber with the film sheets held above the respective support, optionally causing one or both of: a gas withdrawal from the hermetically closed packaging chamber and gas injection of a gas mixture of controlled composition, heat sealing the film to said support, wherein the heat sealing uses one or more heaters having heating surfaces which are heated for discrete and short time periods only. An apparatus for performing the above process is also disclosed.

The invention first relates to a method for welding at least two parts comprising a thermoplastic material and having respective surfaces to be welded, comprising: inserting an insert between the surfaces to be welded of the two parts; generating heat via said insert; wherein the insert moves in relation to the parts to be welded in a welding direction. The invention also relates to an installation adapted for implementation of this method.

Systems and methods are provided for controlling welding. One embodiment is a method for controlling welding of a composite part. The method includes locating a linear fiber optic sensor along a composite part comprising a matrix of thermoplastic reinforced by fibers, measuring temperatures along the weld line via the linear fiber optic sensor, performing induction welding at the composite part along the weld line, determining a continuum of weld temperatures along the weld line, and controlling the induction welding based on the continuum of weld temperatures.

A sealing system (100) for sealing a packaging material is disclosed comprising an independently movable sealing device (101) being movably mounted on a track (102), a power generator (105) in communication with the sealing device (101) to supply a power signal (p1) at a frequency for said sealing over a power communication line (106), the sealing device (101) comprising a housing (107), a detection device (108) arranged in the housing (107) to register detection data of an environment therein and/or of sealing parameters associated with said sealing, and a transmitter (109) connected to the detection device (108), the transmitter comprising an encoder (110) to convert the detection data to at least one frequency pulse (p2), whereby the transmitter (109) communicates the at least one frequency pulse as a detection signal to a receiver (111) over the power communication line (106).

A method for producing a package comprising a formed part having at least one product cavity, and a lidding film covering the at least one product cavity, comprises the steps of: (a) defining a seam; (b) dividing the seam into a plurality of sections; (c) determining a pull-off force for pulling the lidding film from the formed part at least for a first section; and (d) sealing the lidding film to the formed part by means of a sealing device, wherein at least one first sealing temperature is selected for the first section based on the pull-off force determined according to step (c).

A method for producing and inspecting a package comprising at least one product cavity of a formed part sealed by a lidding film comprises the steps of: (a) sealing the lidding film to the formed part along a seam by means of a sealing device, which comprises a sealing contour with a plurality of segments; (b) detecting, by means of the sealing device, a parameter characteristic of the sealing quality of the seam in each segment; and (c) detecting a problem with the sealing according to step (a) based on the parameter detected according to step (b) in each segment.

A method for producing a package which has a formed part with a product cavity, and a lidding film covering the product cavity. According to the method, a seam is defined, the seam is divided into sections, a pull-off force for pulling the lidding film from the formed part at least for a first section is determined, and the lidding film is sealed to the formed part. The sealing temperature for the first section is selected based on the pull-off force.