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Series welding processes for plastic components Process description In the case of hot gas butt welding, the heat is input by means of convection and heat conduction. In this respect, the joining faces are plastified by a hot gas jet which emerges from a hot gas nozzle system adapted to the joining part. The process gas can be chosen freely but is selected depending on the oxidation susceptibility of the plastic to be welded. The gas temperature substantially above the melting temperature may lead to thermal or thermal- oxidative damage to the plastic. As in the case of heated tool and infrared welding, the heating and joining phases are carried out separately from each other. After the desired melt layer has been produced, the hot gas tool is removed from between the components which are welded under pressure. The characteristic process parameters are the gas temperature, the volumetric gas flow, the distance between the nozzles and the component surface, the heating time, the joining pressure and the cooling time. The joining process can be carried out with displacement control or force regulation. Areas of application Hot gas butt welding is a fully automatable welding procedure which is basically suitable for all thermoplastic mouldings. It offers the possibility of reliably welding three-dimensional joining faces. Above all, automobile construction components with which complete freedom from particles is demanded are regarded as examples of applications. It is possible to join not only intake and charge air pipes and fuel and hydraulic oil tanks but also headlights. top component hot gas tool bottom component Advantages Disadvantages contactless heating thermal / thermal- oxidative damage to the plastic possible homogeneous welding bead (particle-free) energy input outside the joining zone possible suitability for complex component geometries few scientific foundations suitability for high- temperature plastics high operating costs medium to long process times needed Hot gas butt welding Process description In the case of ultrasonic welding, the high-frequency energy produced in a generator is transformed into high- frequency mechanical oscillations by a sound transducer (converter) and is transmitted to the component by the welding tool (sonotrode). In this respect, the entire oscillation system (consisting of the converter, the transformation piece and the sonotrode) works in resonance. In the case of ultrasonic welding, the working frequency is typically between 20,000 Hz and 40,000 Hz. The heat needed for the welding is produced by the dissipation of the mechanical oscillation energy in the joining zone. In this respect, the high-frequency oscillations are absorbed and lead to molecular and interfacial friction and, as a consequence of this, to the plastification of the plastic. In the case of ultrasonic welding, a special joining zone geometry in the form of an energy director (ED) is necessary for targeted energy input and for weld formation appropriate for the application. The parameters which are particularly relevant to the process are the working frequency of the ultrasonic welding machine, the oscillation amplitude, the joining pressure or the joining pressure profile and the hold time. The welding process can be carried out with displacement control, time control or energy regulation. Areas of application Typical areas of application are the automobile, packaging and electronics industries as well as medical technology. Because of the very short process times, ultrasonic welding is outstandingly suitable for utilisation in series production. As a consequence of the size restriction on the welding tool, the procedure is suitable particularly for small to medium-sized components made of thermoplastics as well as for the welding of films and non-woven materials. Ultrasonic welding Advantages Disadvantages very short process times special joining face design (ED) high degree of automation possible high material and geometry dependence energy-efficient and resource-conserving oscillation input into the component low investment costs particle abrasion shortest process times needed converter sonotrode amplitude transformer(booster) Vibration welding Process description In the case of vibration welding, the plastic is heated by the dissipation of friction. With the effect of a joining force, the joining parts are moved relative to each other with an amplitude in the horizontal direction. In this respect, electromagnetic spring systems initiate horizontal oscillations in the top table. The interface between the joining parts is plastified by the transformation of friction energy into heat. This results in a melt layer which is exposed to alternating shear loads by the vibration movement. This gives rise to an additional energy input. Due to the applied joining pressure, melt is pressed into the bead at the same time. Consequently, this constitutes a single- stage welding procedure. With regard to the process management in the case of vibration welding, a distinction is made between the linear/longitudinal and linear/transverse oscillation directions (longitudinal and transverse to the main expansion direction of the joining parts respectively). The characteristic process variables are the oscillation frequency, the oscillation amplitude, the joining force, the joining path and the cooling time. The welding process can be carried out with time or displacement control. In addition, there is the possibility of another substantial reduction in the process time in the case of vibration welding using the process management strategy of the so- called high-pressure approach. Areas of application Vibration welding is suitable for the welding of injection-moulded, extruded or blow-moulded components in series fabrication. It is also possible to weld different materials with each other (e.g. plastic with elastomers, textile fibres or wood materials). The main areas of application are the automobile and household appliance industries. Advantages Disadvantages short cycle times plane weld contours required high weld quality limited suitability for components with integrated electronic components robust installation technology particle abrasion (fluffing) tolerant to contaminations limited suitability for flexible components short process times needed top component bottom component joining path joining force joining force amplitude Laser transmission welding Process description The joining zone is heated and plastified because the electromagnetic energy of the infrared laser radiation is absorbed by the plastic. In the case of laser transmission welding, the joining parts are brought into contact before the welding and the laser beam penetrates the joining part transparent for it and is transformed into heat in the absorbing joining part. The laser-beam-transparent joining part is also heated by heat conduction. Thus, the weld is manufactured by applying a joining pressure. In the case of laser transmission welding, it is possible to bridge only very small moulding tolerances since a gap prevents the heat conduction into the transparent component. A distinction is made between contour welding, simultaneous welding, quasi-simultaneous welding as well as mask welding. The relevant process parameters include the type of laser beam source, the wavelength, the energy per unit length as well as the properties of the spot. Areas of application The main utilisation fields can be found in the electronics industry, medical technology and the automobile industry. Apart from identical plastics, different plastic types can also be welded with each other in so far as their melting temperature ranges coincide sufficiently and both materials are chemically and physically compatible. Advantages Disadvantages small, easily controllable heat- affected zone limited possibililty of gap bridging in order to compensate for fabrication tolerances optically high-quality welds (no squeeze flow in the case of contour welding) cost-intensive installation technology short cycle times complicated protective measures usable for very small and precise components as a rule, the laser beam must be able to pass through one joining member short process times needed hl hl l weld seam laser beam heat-affected zone absorbing material transmitting material Process description In the case of hot tool welding, the joining faces of the mouldings or the semi-finished products are heated by the direct contact to the tempered heated tool and are subsequently welded under pressure. Because the heating and joining operations are carried out at different times, heated tool welding constitutes a multistage procedure. The process is divided into five process phases: alignment, heating, changeover, joining and cooling. During the alignment, the joining faces come into complete contact with the heated tool. Subsequently, a melt layer forms with nearly pressureless heating. Thereafter, the heated tool is removed (changeover) and the components are welded under pressure. After the needed joining path has been covered and the melt has thus been pressed out, the cooling operation takes place under pressure and the melt solidifies. The welding process can be carried out with pressure regulation or displacement control. The characteristic process parameters include the heated tool temperature, the heating time, the joining pressure and the cooling time. Areas of application Heated tool welding is one of the dominant joining technologies in the series fabrication of semi-finished products and mouldings made of thermoplastics. This procedure is characterised by the particular suitability for complex three-dimensional joining faces and the applicability to a large number of plastics. The heated tool butt and socket welding procedures are extremely significant for welding in the pipe and apparatus construction sectors. top component heated tool bottom component Advantages Disadvantages high degree of automation possible complicated tools for 3D structures high degree of maturity long cycle times homogeneous welding bead (particle-free) material adhesion to the heated tool possible tolerant in the case of material differences high running costs (energy) medium to long process times needed Heated tool welding Process description In the case of infrared welding, the heat is input by means of heat radiation. The radiation emitted by the infrared radiator is absorbed by the plastic to be welded. As a rule, the short-wave (0.78 - 1.4 µm) and medium-wave (1.4 - 3 µm) infrared radiation ranges of the light spectrum are applied in this respect. In order to achieve a high efficiency, the emission spectrum of the radiator should be coordinated with the absorption spectrum of the plastic. It must be borne in mind that any filler materials (e.g. carbon black or colour pigments) alter the absorption capacity. A distinction must be made between volume and surface absorption. When short-wave infrared radiators with mostly higher area capacities are used, attention must be paid to any possible thermal damage to the component surface. The process management in the case of infrared welding is similar to that in the case of heated tool welding. After the contactless heating, the infrared radiator is removed from between the components which are subsequently welded under pressure. The parameters characteristic of the process include the radiator type and power, the radiation exposure duration, the radiator distance and the cooling time. The welding process can be carried out with pressure regulation or displacement control. Areas of application Infrared welding is utilised across different sectors. Typical applications are the welding of pipes and large-volume tanks as well as series fabrication in automobile construction. Infrared welding is extremely suitable not only for applications with stringent purity requirements but also for the joining of high-temperature thermoplastics with and without fibre reinforcement (no danger of adhesion or abrasion). Depending on the utilised radiator system, it is possible to weld complex 3D geometries too. Moreover, the infrared technology can be combined with other welding procedures. One typical application is vibration welding in combination with infrared preheating in order to reduce the particle formation. top component infrared lamp bottom component Advantages Disadvantages contactless heating complex radiator/ material dependence high design freedom of the joining faces and the infrared radiator coordination of the emission and absorption behaviour homogeneous welding bead (particle-free) energy input outside the joining zone possible low-stress joints possibly complex radiator construction medium to long process times needed Infrared welding Your competent Partner in Ultrasonic Joining Technology www.telsonic.com www.leister.com www.paneltim.com KLN Ultraschall AG Odenwaldstraße 8 D-64646 Heppenheim Tel.: +49 6252 14-0 Fax: +49 6252 14-277 Email: [email protected] www.kln.de Plastics Welding Technology in Perfection www.wegenerwelding.de © DVS Media GmbH, Düsseldorf The poster contents were compiled by employees of the Professorship of Plastics of the Technical University Chemnitz and employees of the KTP (Kunststofftechnik Paderborn) of the University Paderborn. JOINING PLASTICS – FÜGEN VON KUNSTSTOFFEN Technical Journals, Books, Newsletter & Online Your first choice: Reach TOP decision-makers internationally, directly & precisely! www.joining-plastics.info FÜGEN VON KUNSTSTOFFEN 74999 3-4/2018 Topics of the Peer-reviewed Papers Quality monitoring of laser-beam-welded tapes made of fibre-reinforced plastics by means of ther- mography Laser transmission welding of transparent plastics Quantification of the material damping properties using the mandrel melting-in test Laser beam microwelding of transparent plastics www.fuegen-von-kunststoffen.de www.joining-plastics.info JOINING PLASTICS JOINING PLASTICS - FÜGEN VON KUNSTSTOFFEN 3-4/18 Supported by Themen der Fachbeiträge Qualitätsüberwachung laserstrahlgeschweißter Tapes aus faserverstärkten Kunststoffen mittels Thermografie Laserdurchstrahlschweißen transparenter Kunststoffe zierung der Werkstoff-Dämpfungseigenschaf- inschmelzversuch von transparenten VON DER PROJEKTIDEE ZUM PROTOTYPEN? CHWEIS V S TI EFFEK ER EFFIZI EB I L SEN? CHWEIS ER D ENT O ER EFFIZI O T ZUM PRO ER PRO N D VO YPEN? T TY O EE D TI JEK ER PRO TEN? ERA GUT B ÜG ER F N D I TEN? K I TECHN E ÜG Kunststoffschweißtechnik in Perfektion Plastics Welding Technology in Perfection www.wegenerwelding.de [email protected] Besuchen Sie uns: Halle 11, Stand A40 Visit us: Hall 11, Stand A40 Warmgasschweißgeräte Extrusionsschweißgeräte Stumpfschweißmaschinen Biegemaschinen Sondermaschinen Hot Air Welding Tools Extrusion Welders Butt Welding Machines Bending Machines Custom Designed Machines joining_plastics210x150_Layout 1 25.01.2019 13:59 Seite 1 1⁄2019 Themen der Fachbeiträge Fügetechnologien in der Luftfahrt Untersuchungen zur Dimensionierung der statischen Auszugsfestigkeit des Schraub- blindniets Hybridfügen von Metall und Kunststoff belastung von Ultraschallschweißver- zyklischer Lasten Topics of the Peer-reviewed Papers Joining technologies in aviation Investigations into the dimensioning of the static pull-out strength of the screwed blind rivet Hybrid joining of metal and plastic Long-term exposure of ultrasonic welded joints - Influence of cyclic loads www.fuegen-von-kunststoffen.de ww.joining-plastics.info JOINING PLASTICS FÜGEN VON KUNSTSTOFFEN Supported by 74999 HSK Kunststoff Schweisstechnik GmbH Kunststoff Schweißtechnik plastic welding technology E-mail: [email protected] Internet: www.hsk-kunststoff.de Tel.: +49 2224 90175 01 Fax: +49 2224 90175 03 HSK Kunststoff Schweisstechnik GmbH Zilzkreuz 1 D-53604 Bad Honnef Germany Anz_210x150_Layout 1 20.04.2015 18:37 Seite 1 2⁄2019 Themen der Fachbeiträge Evaluierung von Strahloszillationsmustern beim quasi-simultanen Laserdurchstrahlschweißen Reaktive Multischichtsysteme zum Fügen von Kunststoff- und Hybridverbindungen Inline-Überwachung der Klebstoffaushärtung mit berührungslosem Ultraschall Laserdurchstrahlschweißen transparenter Kunststoffe – Teil 2 Topics of the Peer-reviewed Papers Evaluation of beam oscillation patterns during quasi-simultaneous laser transmission welding Reactive multilayer systems for plastic and hybrid joints Inline monitoring of the adhesive curing with contactless ultrasound Laser transmission welding of transparent plastics – Part 2 www.fuegen-von-kunststoffen.de www.joining-plastics.info JOINING PLASTICS FÜGEN VON KUNSTSTOFFEN Supported by 74999 FÜGEN VON KUNSTSTOFFEN 74999 3-4/2018 Topics of the Peer-reviewed Papers Quality monitoring of laser-beam-welded tapes made of fibre-reinforced plastics by means of ther- mography Laser transmission welding of transparent plastics Quantification of the material damping properties using the mandrel melting-in test Laser beam microwelding of transparent plastics www.fuegen-von-kunststoffen.de www.joining-plastics.info JOINING PLASTICS JOINING PLASTICS - FÜGEN VON KUNSTSTOFFEN 3-4/18 Supported by Themen der Fachbeiträge Qualitätsüberwachung laserstrahlgeschweißter Tapes aus faserverstärkten Kunststoffen mittels Thermografie Laserdurchstrahlschweißen transparenter Kunststoffe zierung der Werkstoff-Dämpfungseigenschaf- inschmelzversuch von transparenten VON DER PROJEKTIDEE ZUM PROTOTYPEN? CHWEIS V S TI EFFEK ER EFFIZI EB I L SEN? CHWEIS ER D ENT O ER EFFIZI O T ZUM PRO ER PRO N D VO YPEN? T TY O EE D TI JEK ER PRO TEN? ERA GUT B ÜG ER F N D I TEN? K I TECHN E ÜG Kunststoffschweißtechnik in Perfektion Plastics Welding Technology in Perfection www.wegenerwelding.de [email protected] Besuchen Sie uns: Halle 11, Stand A40 Visit us: Hall 11, Stand A40 Warmgasschweißgeräte Extrusionsschweißgeräte Stumpfschweißmaschinen Biegemaschinen Sondermaschinen Hot Air Welding Tools Extrusion Welders Butt Welding Machines Bending Machines Custom Designed Machines joining_plastics210x150_Layout 1 25.01.2019 13:59 Seite 1 1⁄2019 Themen der Fachbeiträge Fügetechnologien in der Luftfahrt Untersuchungen zur Dimensionierung der statischen Auszugsfestigkeit des Schraub- blindniets Hybridfügen von Metall und Kunststoff belastung von Ultraschallschweißver- zyklischer Lasten Topics of the Peer-reviewed Papers Joining technologies in aviation Investigations into the dimensioning of the static pull-out strength of the screwed blind rivet Hybrid joining of metal and plastic Long-term exposure of ultrasonic welded joints - Influence of cyclic loads www.fuegen-von-kunststoffen.de ww.joining-plastics.info JOINING PLASTICS FÜGEN VON KUNSTSTOFFEN Supported by 74999 HSK Kunststoff Schweisstechnik GmbH Kunststoff Schweißtechnik plastic welding technology E-mail: [email protected] Internet: www.hsk-kunststoff.de Tel.: +49 2224 90175 01 Fax: +49 2224 90175 03 HSK Kunststoff Schweisstechnik GmbH Zilzkreuz 1 D-53604 Bad Honnef Germany Anz_210x150_Layout 1 20.04.2015 18:37 Seite 1 2⁄2019 Themen der Fachbeiträge Evaluierung von Strahloszillationsmustern beim quasi-simultanen Laserdurchstrahlschweißen Reaktive Multischichtsysteme zum Fügen von Kunststoff- und Hybridverbindungen Inline-Überwachung der Klebstoffaushärtung mit berührungslosem Ultraschall Laserdurchstrahlschweißen transparenter Kunststoffe – Teil 2 Topics of the Peer-reviewed Papers Evaluation of beam oscillation patterns during quasi-simultaneous laser transmission welding Reactive multilayer systems for plastic and hybrid joints Inline monitoring of the adhesive curing with contactless ultrasound Laser transmission welding of transparent plastics – Part 2 www.fuegen-von-kunststoffen.de www.joining-plastics.info JOINING PLASTICS FÜGEN VON KUNSTSTOFFEN Supported by 74999
