Volume 06 - Welding, Brazing and Soldering Part 17 docx

transfers the vibratory motion to the workpiece. The converter, booster, and horn must be resonant at the operating frequency. FIG. 11 SCHEMATIC OF ULTRASONIC-WELDING COMPONENTS The weldability of any polymer depends on the damping capacity, or attenuation characteristics, and size of the component being joined. Depending on the distance between the sonotrode and the bond line, ultrasonic welding is classified as being either near-field (for distances under 6 mm, or 0.24 in.) or far-field (for distances over 6 mm, or 0.24 in.) welding. It follows that the component geometry has a crucial influence on energy transmission, heat generation, and polymer melting at the joint interface. The transmission of ultrasonic vibrations through the workpiece sets up standing-wave patterns and regions of maximum and minimum displacements (Ref 34). The material fuses in regions of maximum strain or stress. Amorphous thermoplastics are more readily weldable when an energy director is used. A triangular projection is molded onto one of the specimen surfaces, usually the one that contacts the sonotrode (Fig. 12a). Ultrasonic welds in semicrystalline resins are commonly produced using an interference, or shear joint, design (Fig. 12b). A novel technique that utilizes a tielayer at the interface has been developed recently (Fig. 12c) for use during the ultrasonic welding of flat contacting surfaces. FIG. 12 SCHEMATIC OF ULTRASONIC CONFIGURATION. (A) ENERGY DIRECTOR DESIGN. (B) SHEAR JO INT DESIGN. (C) TIE-LAYER DESIGN. SOURCE: REF 35 AND 36 Energy generation and welding-parameter optimization during the ultrasonic welding of polystyrene (PS), a blend of PC and polybutylene terephthalate, and a composite of polyetherether ketone (PEEK) and graphite APC-2 have been analyzed in detail by different authors (Ref 37, 38, 39). The joining process comprises four distinct phases when tie layers are employed (Fig. 13). The rapid increase in temperature up to the polymer melting point results from frictional heating at surface asperities and, to a much lesser extent, viscoelastic dissipation. In phase II of the ultrasonic-welding process, bulk melting of the interface region predominantly results from viscoelastic energy dissipation. Further heating is due to viscous dissipation during phase III. In phase IV, the joint cools under pressure. FIG. 13 TYPICAL PROCESS DATA TRACES-TIME GRAPH OF ULTRASONIC-WELDING PROCESS WHEN USING TIE LAYERS AT THE INTERFACE. SOURCE: REF 40 The weldability of a thermoplastic can be defined using the following relationships (Ref 3): 2 1 0,7 tan0.25 '1 2 T T x c dt P Ev P ρ φ δ π =      +−        (EQ 4) ∧ = πTAN δ (EQ 5) where φ is the energy index, T 1 is the ambient temperature, T 2 is the softening point or crystalline melting point of the polymer, ρ is the density, c is the specific heat, E' is the real component of the complex elastic modulus, tan δ is the mechanical loss factor, P and P x are the joining and critical joining pressure values, respectively, v is the coefficient of friction, and ∧ is the logarithmic damping decrement. When the φ value increases, more energy is required during the ultrasonic-welding process. When the logarithmic decrement factor ∧ has a low value, more energy arrives at the joint interface. The φ and ∧ indexes are plotted in Fig. 14. FIG. 14 DIAGRAM FOR ASSESSMENT OF WELDING CAPACITY OF THERMOPLASTIC S. ARROW DIRECTION SHOWS INCREASE IN WELDABILITY BY THE INDIRECT METHOD. LDPE, LOW-DENSITY POLYETHYL ENE; HDPE, HIGH-DENSITY POLYETHYLENE; PA, POLYAMIDE; POM, POLYOXYMETHYLENE. SOURCE: REF 34 The key joining parameters of ultrasonic welding are the: • AMPLITUDE OF VIBRATION DURING JOINING • PRESSURE APPLIED DURING THE WELDING OPERATION • JOINT GEOMETRY WHEN WELDING AMORPHOUS AND SEMICRYSTALLINE POLYMERS • WELDING TIME AND ENERGY APPLIED DURING THE WELDING PROCESS • TRIGGER PRESSURE/FORCE RELATIONSHIP (THE PRESSURE A T WHICH ULTRASONIC VIBRATIONS ARE INITIATED) Applications. The success of ultrasonic welding lies in the fact that the process is very fast (welding times are approximately 1 s), the equipment is compact, the process can be readily automated, and consistently acceptable weld quality can be produced. Ultrasonic welding is commonly used to join components in the automotive, toy, domestic appliance, and packaging industries. It is also the method of choice when welding many medical plastic components. The only limitation is that large parts cannot be welded using this method. References cited in this section 3. H. POTENTE AND P. MICHEL, THE STATE OF THE ART DEVELOPMENT T RENDS IN THE WELDING OF PLASTICS, PROC. 5TH ANNUAL NORTH AMERICAN WEL DING RESEARCH CONFERENCE, EWI AND AWS, 1989 10. A. BENATAR, MATERIAL CHARACTERISTICS FOR WELDING, PROC. 5TH ANNUAL NOR TH AMERICAN WELDING RESEARCH CONFERENCE, EWI AND AWS, 1989 26. V.K. STOKES, VIBRATION WELDING OF THERMOPLASTICS, PART I, POLYM. ENG. SCI., VOL 28, 1988, P 718-727 27. E. PECHA, D. CALINSKI, AND H. DIETER, PRODUCTION MACHINES AN D TECHNICAL APPLICATION FOR HOT PLATE AND VIBRATION WELDING, PROC. LNT. CONF. ADV ANCES IN JOINING PLASTICS AND COMPOSITES, THE WELDING INSTITUTE, CAMBRIDGE, 1991 28. V.K. STOKES, VIBRATION WELDING OF THERMOPLASTICS, PART II, POLYM. ENG. SCI., VOL 28, 1988, P 727-739 29. H. POTENTE AND H. KAISER, PROCESS VARIANT OF VIBRATION WELDI NG WITH VARIABLE WELDING PRESSURE, PROC. SPE 48TH ANTEC MEETING, SOCIETY OF PLASTICS EN GINEERS, 1990, P 1762-1765 30. H. POTENTE AND M. UEBBING, COMPUTER AIDED LAYOUT OF THE VIBR ATION WELDING PROCESS, PROC. SPE 50TH ANTEC MEETING, 1992, SOCIETY OF PLASTICS ENGINEERS, P 888 31. M. CAKMAK AND K. KEUCHEL, U.S. PATENT 4,998,663, MARCH 1991 32. K. KEUCHEL AND M. CAKMAK, SPIN WELDING OF POLYPROPYLENE: CHA RACTERIZATION OF HEAT AFFECTED ZONE BY MICRO-BEAM WAXS TECHNIQUE, PROC. SPE 49TH ANTEC MEETING, SOCIETY OF PLASTICS ENGINEERS, 1991, P 2477-2481 33. H. RAJARAMAN AND M. CAKMAK, THE EFFECT OF GLASS FIBER FILLERS ON THE WELDING BEHAVIOR OF POLY P-PHENYLENE SULFIDE, PROC. SPE 50TH ANTEC MEETING, SOCIETY OF PLASTICS ENGINEERS, 1992, P 896-899 34. H. POTENTE, ULTRASONIC WELDING PRINCIPLES AND THEORY, MAT. DES., VOL 5, 1984 35. T.B. ZACH, J. LEW, T.H. NORTH, AND R.T. WOODHAMS, "JOINING O F HIGH STRENGTH ORIENTED POLYPROPYLENE USING ELECTROMAGNETIC INDUCTION BONDI NG AND ULTRASONIC WELDING, MAT. SCI. TECH., VOL 5, 1989, P 281-287 36. J.S. WOLCOTT, DESIGNING PARTS FOR ULTRASONIC ASSEMBLY, PROC. SPE 48T H ANTEC MEETING, SOCIETY OF PLASTICS ENGINEERS, 1990, P 1829-1833 37. M.N. TOLUNAY, P.R. DAWSON, AND K.K. WANG, HEATING AND BONDIN G MECHANISMS IN ULTRASONIC WELDING OF THERMOPLASTICS, POLYM. ENG. SCI., VOL 23, 1983, P 726-733 38. G. HABERNICHT AND J. RITTER, ENERGY CONVERSION IN THE ULTRASONIC WELDING OF THERMOPLASTICS, KUNSTST. GER. PLAST., VOL 78, 1988, P 49-66 39. A. BENATAR AND T.G. GUTOWSKI, ULTRASONIC WELDING OF PEEK GRAPHITE APC- 2 COMPOSITES, POLYM. ENG. SCI., VOL 29 (NO. 23), 1989, P 1705-1721 40. N. TATEISHI, T.H. NORTH, AND R.T. WOODHAMS, ULTRASONIC WELDING USING TIE- LAYERS, PART I: ANALYSIS OF PROCESS OPERATION, POLYM. ENG. SCI., VOL 32, 1992, P 600- 611 Welding of Plastics Thomas H. North and Geetha Ramarathnam, University of Toronto Electromagnetic Welding The joining techniques described in this section include resistance, induction, dielectric, and microwave welding. Resistance or Implant Welding In this technique, a conducting wire or mesh is inserted at the interface between the parts being welded. This insert is resistively heated by the passage of electric current (Fig. 15a), which melts the thermoplastic surrounding the insert, forming a weld. It should be noted that the implant remains in the completed joint. Electrofusion is a technique whereby the two ends of the pipe to be welded are inserted into a fitting/collar/coupler, the inside of which constitutes the heating element (Ref 41, 42). The electric current that passes through the heating element promotes melting on the inside surface of the fitting. Figure 15(b) shows a typical rectangular cross section of an electrofusion weld. FIG. 15 (A) ELECTROFUSION (RESISTANCE) WELDING PROCESS. (B) ELECTROFUSION WELDING PROCESS. SOURCE: REF 42 The key joining parameters are the: • APPLIED VOLTAGE AND APPLIED CURRENT, WHICH CAN BE AS HIGH AS 150 A • CLAMPING PRESSURE DURING WELDING • HEATING TIME • AVOIDANCE OF CONTACTING SURFACE CONTAMINATION. BECAUSE MELT FLOW IS RESTRICTED DURING WELDING, IMPURITIES CAN BE TRAPPED AT THE JOINT INTERFACE, REDUCING THE STRENGTH OF THE WELD Applications. The principal advantage of this joining method is that the equipment is relatively simple and portable. Therefore, it can be used in on-site repair situations. The primary application area for electrofusion welding is the joining of PE pipes with diameters less than 180 mm (7 in.), which are used for water transportation and natural gas distribution (Ref 42). Induction Welding In this joining method, a layer of electromagnetic material in the form of a tape or a thin sheet is placed at the joint interface. This insert material is heated using a high-frequency (2 to 10 MHz) inductive supply (Ref 43, 44). The electromagnetic tapes contain conductive and ferromagnetic particles. The particle size, type, and concentration depend on the application desired. The welding equipment comprises a high-frequency induction generator, a water-cooled copper working coil, and press fixtures, which hold the polymer component so that it can be heated and loaded. Heating results from eddy currents that are induced in the thermoplastic tape containing the ferromagnetic particles (Fig. 16), and energy generation is proportional to I 2 R. Heat generation during electromagnetic welding has been modeled, particularly for cross-ply carbon fiber thermoplastic composites (Ref 45, 46). FIG. 16 INDUCTION-HEATING MECHANISM. SOURCE: REF 5 The key joining parameters of this technique are the: • COIL DESIGN, WHICH MUST BE CAREFULLY TAILORED TO SUIT THE END USE AND TO PRODUCE A UNIFORM RADIO-FREQUENCY (RF) FIELD. A RANGE OF COIL DESIGNS (SINGLE TURN, MULTITURN, HELICAL, BENT HAIRPIN, AND SO ON) ARE ALL POSSIBLE • FREQUENCY AND POWER OUTPUT OF THE INDUCTION GENERATOR • PARTICLE SIZE AND TYPE OF FILLER USED IN ELECTROMAGNETIC TAPE MANUFACTURE • DISTANCE BETWEEN THE INDUCTOR COILS AND THE BOND LINE Applications. The principal advantage of this joining method is that it can handle components of complex geometry. The process is also suitable for joining filled thermoplastic materials. The primary applications are in the automotive, packaging, and appliance industries. In the medical field, electromagnetic induction welding has been employed for joining PC blood oxygenators and arterial filter components. The principal disadvantages of this joining process are the high cost of the equipment, the recurring costs associated with the purchase of ferromagnetic-filled tapes, and the care that is required in the design and construction of the inductive heating coils. Dielectric Welding In dielectric welding, the joint interface is subjected to much higher RF electrical energy. The process utilizes these major components: • A GENERATOR THAT PRODUCES A FREQUENCY RANGING FROM 13 TO 100 MHZ (27.12 MHZ IS TYPICAL) OF ELECTRICAL ENERGY AT AN OUTPUT OF 1 TO 25 KW • A PRESS THAT CLAMPS THE SECTIONS TOGETHER DURING THE HEATING AND SUBSEQUENT COOLING CYCLES • A BRASS ELECTRODE OR DIE THAT IS MOUNTED ON AN ALUMINUM PLATE, WHICH APPLIES THE ELECTRICAL ENERGY DIRECTLY TO THE PLASTIC (REF 47) The key joining parameters of this process are the: • DIELECTRIC LOSS FACTOR OF THE POLYMER OR THE PRESENCE OF A DIPOLE, BECAUSE A HIGH DIELECTRIC LOSS FACTOR INCREASES THE EFFECTIV ENESS OF THE JOINING OPERATION • THICKNESS OF THE MATERIAL BEING JOINED • OUTPUT POWER AND FREQUENCY OF THE GENERATOR EMPLOYED DURING WELDING Applications. Dielectric welding is a fast, efficient joining method for sealing thin polymer films and sheet materials. The equipment can be readily automated. However, the process can only be used on materials that have a high dielectric loss factor, such as rigid or flexible PVC, ABS, and thermoplastic polyurethane materials. The principal application area is in the packaging industry, where the process is used to join medical components, such as blood-pressure cuffs, medical bags, rainwear, pool liners, and so on. The primary disadvantage of this joining technique is that the initial equipment cost is high. Microwave Joining This joining technique depends on the heat produced by microwave-frequency radiation. The parts being joined are held together under a slight pressure of 35 to 70 kPa (5 to 10 psi), and then the interface is irradiated by electromagnetic (EM) radiation using well-focused horn antennas. In order to absorb EM energy, the polymer must contain polar groups. To attain viable heating, either a nonconducting or a low-conductivity polymer may have to be doped with conducting polymer or, as an alternative, an adhesive film that contains polar and/or electron-withdrawing groups can be placed at the joint interface (Ref 48). This joining method is relatively new and is still in the experimental stage. The experimental equipment (Ref 48) consists of a magnetron tube that generates the microwave energy, a ferrite isolator that shields the magnetron and promotes the efficient transmission of power with very little attenuation, a forward/reflected-power indicator that monitors the whole system while it is in operation, a tuner that can be adjusted to minimize the reflected power and aid in the maximum transfer of power from the source to the workpiece, a variable-coupling iris that optimizes and adjusts the power coupled to the load, and, finally, an applicator that concentrates the microwave power at the joint region. The key joining parameters of this process are the: • MICROWAVE PROPERTIES OF THE MATERIAL, SUCH AS PERMITTIVITY A ND PERMEABILITY • FREQUENCY AND ENERGY OF THE MICROWAVE SUPPLY Applications. This welding technique is simple, fast, clean, and very efficient in terms of energy conversion. Consequently, short welding times are involved. Dissimilar materials can be joined, and the use of a microwave- absorbing adhesive will permit the repair of thermoset- or thermoplastic-based composite materials. This joining method can be very useful for in-situ repairs of structures, especially on space vehicles and other aircraft. References cited in this section 5. R.A. GRIMM, FUSION WELDING TECHNIQUES FOR PLASTICS, WELD. J., MARCH 1990, P 23-28 41. R.G. WILLIAMS, DEVELOPMENT OF A NOVEL ELECTROFUSION SYSTEM," GAS ENGINEERING AND MANAGEMENT, VOL 26, 1986, P 43-46 42. J.R. ATKINSON AND I.M. WARD, THE JOINING OF BIAXIALLY ORIENTED POLYETHYLENE PIPES, POLYM. ENG. SCI., VOL 29 (NO. 23), 1989, P 1638-1641 43. SM. CHOOKAZIAN, BONDING PLASTICS BY INDUCTION HEATING, SPE J., VOL 26, 1970, P 49- 53 44. A. LEATHERMAN, INDUCTION BONDING FINDS A NICHE IN AN EVOLVIN G PLASTICS INDUSTRY, PLAST. ENG., VOL 4, 1981, P 27-29 45. S.P. MOLNAR, CHARACTERIZATION AND CONTROL OF INDUCTION FUSIO N BONDING OF THERMOPLASTIC COMPOSITE,PROC. SPE 50TH ANTEC MEETING, SOCIETY OF PLASTICS ENGINEERS, 1992, P 2102-2105 46. B.K. FINK, R.L. MCCULLOUGH, AND J.W. GILLESPIE JR., A LOCAL THEORY OF HEATING IN CROSS-PLY CARBON FIBER THERMOPLASTIC COMPOSITES BY MAGNETIC INDUCT ION, POLYM. ENG. SCI., VOL 32, 1992, P 357-369 47. C.J. GIANNANDREA, RADIO FREQUENCY SEALING, MOD. PLAST., ENCYCLOPEDIA ISSUE, OCT 1990, P 386-388 48. V.K. VARADAN AND V.V. VARADAN, MICROWAVE JOINING AND REPAIR OF COMPOSITE MATERIALS, POLYM. ENG. SCI., VOL 31, 1992, P 470-486 Welding of Plastics Thomas H. North and Geetha Ramarathnam, University of Toronto Evaluation of Welds Because polymers are being used increasingly for semistructural and load-bearing applications, the testing of the welded joints is important. The mechanical properties of welded plastics can be evaluated by performing standard destructive tests, such as tensile, peel, wedge, and four-point bending. Of particular interest is the development of short-term tests (Ref 49), where a hole is notched in the weld area (to create multiaxial stress). These short-term tests are for quality- assurance purposes only. For long-term applications, creep tests are much more favored. The measurement of thermal and residual stress has been evaluated using the Moire interferometric method (Ref 50). The microstructure of the weld zone can be examined using light microscopy, scanning electron microscopy (SEM), or x- ray techniques (Ref 32, 51, 52). The microstructural examination of bonded regions is important because it allows: • MEASUREMENT OF THE WELD ZONE AND HEAT-AFFECTED ZONE DIMENSIONS AND THEIR UNIFORMITY ALONG THE WELD LINE • EVALUATION OF THE DEVELOPMENT OF CRYSTALLINITY, ESPECIALLY THE TRANSCRYSTALLINE REGION • EVALUATION OF THE CHAIN ORIENTATION, ESPECIALLY PARALLEL TO THE BOND- LINE REGION • ESTIMATION OF THE FAILURE MODES OF MECHANICALLY TESTED WELD SECTIONS • OPTIMIZATION OF WELDING CONDITIONS IN ORDER TO CONSISTENTLY PRODUCE JOINTS OF OPTIMUM STRENGTH Nondestructive evaluation (NDE) techniques for the detection of flaws in metal joints are well established. However, in the case of plastic joints, much work is still required to optimize the application of NDE techniques (Ref 53). References cited in this section 32. K. KEUCHEL AND M. CAKMAK, SPIN WELDING OF POLYPROPYLENE: CHA RACTERIZATION OF HEAT AFFECTED ZONE BY MICRO-BEAM WAXS TECHNIQUE, PROC. SPE 49TH ANTEC MEETING, SOCIETY OF PLASTICS ENGINEERS, 1991, P 2477-2481 49. G. MENGES, E. SCHMACHTENBERG, AND R. KRAUSENBERGER, EIN SCHN ELLER WEG ZUR ERMITTLUNG DES LANGZEITVERHALTENS VON SCHWEIßNAHTEN, DVS BER., VOL 84, P 62- 65 50. J.B. PARK AND A. BENATAR, MOIRE INTERFEROMETRY MEASUREMENT O F RESIDUAL STRAINS IN IMPLANT RESISTANCE WELDING, PROC. SPE 50TH ANTEC MEETING, SOCIETY OF PLASTICS ENGINEERS, 1992, P 353-358 51. L.C. SAWYER AND D.T. GRUBB, IN POLYMER MICROSCOPY, CHAPMAN AND HALL, 1987 52. M.J. DAY AND M.F. GITTOS, "THE APPLICATION OF LIGHT MICROSCO PY TO WELDED JOINTS IN THERMOPLASTICS," REPORT 390, THE WELDING INSTITUTE, 1989 53. G.R. EDWARDS, NONDESTRUCTIVE EVALUATION OF WELDS IN PLASTICS, PROC. 5TH ANNUAL NORTH AMERICAN WELDING RESEARCH CONFERENCE, EWI AND AWS, 1989 Welding of Plastics Thomas H. North and Geetha Ramarathnam, University of Toronto References General Review Articles on Joining and Welding of Polymers: 1. G. GEHARDSSON, THE WELDING OF PLASTICS, WELD. REV., FEB 1983, P 17-22 2. M.N. WATSON, R.M. RIVETT, AND K.I. JOHNSON, "PLASTICS AN INDUSTRIAL AND LITERATURE SURVEY OF JOINING TECHNIQUES," REPORT NO. 7846.01/ 85/471.3, THE WELDING INSTITUTE, ABINGTON, UK, 1986 3. H. POTENTE AND P. MICHEL, THE STATE OF THE ART DEVELOPMENT T RENDS IN THE WELDING OF PLASTICS, PROC. 5TH ANNUAL NORTH AMERICAN WELDING RESEAR CH CONFERENCE, EWI AND AWS, 1989 4. V.K. STOKES, JOINING METHODS FOR PLASTICS AND PLASTIC COMPOS ITES: AN OVERVIEW, POLYM. ENG. SCI., VOL 29 (NO. 19), 1989, P 1310-1324 5. R.A. GRIMM, FUSION WELDING TECHNIQUES FOR PLASTICS, WELD. J., MARCH 1990, P 23-28 6. G. MENGES, THE JOINING OF PLASTICS AND THEIR COMPOSITES, PROC. LNT. CONF. ADVANCES IN JOINING NEWER STRUCTURAL MATERIALS, IIW (MONTREAL), P 33-63 Adhesive Bonding: 7. A.J. KINLOCH, ADHESION AND ADHESIVES, CHAPMAN AND HALL, 1987, P 101 Mechanical Fastening: 8. D. CHANT, JOINING TECHNOLOGY FOR THERMOPLASTIC COMPOSITE STR UCTURES IN AEROSPACE APPLICATIONS, PROC. INT. CONF. ADVANCES IN JOINING PLA STICS AND COMPOSITES, THE WELDING INSTITUTE, CAMBRIDGE, 1991 Welding Mechanisms and Weldability of Thermoplastics: 9. S.S. VOYUTSKII, AUTOHESION AND ADHESION OF HIGH POLYMERS, WI LEY INTERSCIENCE, 1963 10. A. BENATAR, MATERIAL CHARACTERISTICS FOR WELDING, PROC. 5TH ANNUAL NOR TH AMERICAN WELDING RESEARCH CONFERENCE, EWI AND AWS, 1989 11. R.P. WOOL, B L. YUAN, AND O.J. MCGAREL, POLYM. ENG. SCI., VOL 29 (NO. 19), 19 89, P 1340-1367 Solvent Welding: 12. W.V. TITOW, CHAPTER 12, SOLVENT WELDING OF PLASTICS, APPLIED SCIENCE PUBLISHERS, LONDON, P 181-196 [...]... to the off-line planning system Standards In order for the real-time controller to communicate with the welding process systems and with the off-line planner, it is important that standards be established for the storage and communication of computerized welding information The AWS A9 and D16 Committees are developing such standards, and the reader is referred to AWS/ANSI A9. 1-9 2 and A9. 2-9 2, as well... Society (AWS) A9 Committee as part of a standard (A9.3) for such interfaces The JDF, JTF, PSF, WSF, WPF, RTF, PSF, JPF, and JNF are generated by the off-line planner and sent to the real-time controller The JIF and JRF store information retrieved during weld job execution from the real-time controller These files are then sent back to the off-line planner in order to update it and to provide additional...13 M LICATA AND E HAAG, SOLVENT WELDING WITH POLYCARBONATE, PROC SPE 44TH ANTEC MEETING, SOCIETY OF PLASTICS ENGINEERS, 1986, P 109 2-1 094 Heated-Tool Welding: 14 K GABLER AND H POTENTE, WELDABILITY OF DISSIMILAR THERMOPLASTICS-EXPERIMENTS IN HEATED TOOL WELDING, J ADHES., VOL 11, 1980, P 14 5-1 63 15 H POTENTE AND P TAPPE, SCALE-UP LAWS IN HEATED TOOL BUTT WELDING OF HDPE AND PP, POLYM ENG SCI.,... 25 W.W DULEY AND R.E MUELLER, CO2 LASER WELDING OF POLYMERS, POLYM ENG SCI., VOL 32 (NO 9), 1992, P 58 2-5 85 Vibration Welding: 26 V.K STOKES, VIBRATION WELDING OF THERMOPLASTICS, PART I, POLYM ENG SCI., VOL 28, 1988, P 71 8-7 27 27 E PECHA, D CALINSKI, AND H DIETER, PRODUCTION MACHINES AND TECHNICAL APPLICATION FOR HOT PLATE AND VIBRATION WELDING, PROC LNT CONF ADVANCES IN JOINING PLASTICS AND COMPOSITES,... ENG SCI., VOL 29 (NO 23), 1989, P 170 5-1 721 40 N TATEISHI, T.H NORTH, AND R.T WOODHAMS, ULTRASONIC WELDING USING TIELAYERS, PART I: ANALYSIS OF PROCESS OPERATION, POLYM ENG SCI., VOL 32, 1992, P 60 0-6 11 Electrofusion (Resistance) Welding: 41 R.G WILLIAMS, DEVELOPMENT OF A NOVEL ELECTROFUSION SYSTEM," GAS ENGINEERING AND MANAGEMENT, VOL 26, 1986, P 4 3-4 6 42 J.R ATKINSON AND I.M WARD, THE JOINING OF BIAXIALLY... Xu and Jerald E Jones, American Welding Institute Off-Line Planning System An intelligent off-line planning system comprises several modules WELDEXCELL, for example, contains four: the parts designer, path planner, welding schedule developer, and system integrator (Fig 2) FIG 2 SEQUENTIAL OPERATION OF AN OFF-LINE PLANNING SYSTEM Parts Designer The parts to be joined should first be drawn in a three-dimensional... PROCEDURE SPECIFICATION AND STRUCTURE INTEGRITY ANALYSIS, PROC 2ND INT CONF ON TRENDS IN WELDING RESEARCH, ASM INTERNATIONAL 1990, P 98 5-9 89 Intelligent Automation for Joining Technology Xiaoshu Xu and Jerald E Jones, American Welding Institute Interface Between Off-Line Planners and Real-Time Control Systems The interface is the communication link between the off-line planner and the real-time control system... POLYM ENG SCI., VOL 29 (NO 23), 1989, P 164 2-1 648 16 H POTENTE AND J NATROP, COMPUTER AIDED OPTIMIZATION OF THE PARAMETERS OF HEATED TOOL BUTT WELDING, POLYM ENG SCI., VOL 29 (NO 23), 1989, P 164 9-1 654 17 A.J POSLINSKI AND V.K STOKES, ANALYSIS OF THE HOT-TOOL WELDING PROCESS, PROC SPE 50TH ANTEC MEETING, 1992, SOCIETY OF PLASTICS ENGINEERS, P 122 8-1 233 Hot-Gas Welding: 18 H GUMBLETON, HOT GAS WELDING... P 21 5-2 18 19 "RECOMMENDED PRACTICES FOR JOINING PLASTIC PIPING," DOCUMENT XVI-32 2-7 8-E, IIW Extrusion Welding: 20 P MICHEL, "AN ANALYSIS OF THE EXTRUSION WELDING PROCESS," POLYM ENG SCI., VOL 29 (NO 19), 1989, P 137 6-1 382 21 M GEHDE AND G.W EHRENSTEIN, STRUCTURAL AND MECHANICAL PROPERTIES OF OPTIMIZED EXTRUSION WELDS, POLYM ENG SCI., VOL 31 (NO 7), 1991, P 49 5-5 01 Infrared Welding: 22 H SWARTZ AND J.L... soon to be published standards, such as AWS/ANSI A9.3 and A9.4, and ASTM E49 Committee standards Real-Time Control System The real-time control system comprises six major modules: • • • • • • THE INTERFACE TO A JOB DATA FILE OR AN OFF-LINE PLANNER THE JOB INTERPRETER THE JOB EDITOR AND USER INTERFACE THE HARDWARE CONTROLLER OF THE WELDING CELL THE HARDWARE OF THE WELDING CELL AND THE ASSOCIATED SENSORS . PEEK GRAPHITE APC- 2 COMPOSITES, POLYM. ENG. SCI., VOL 29 (NO. 23), 1989, P 170 5-1 721 40. N. TATEISHI, T.H. NORTH, AND R.T. WOODHAMS, ULTRASONIC WELDING USING TIE- LAYERS, PART I: ANALYSIS. PEEK GRAPHITE APC- 2 COMPOSITES, POLYM. ENG. SCI., VOL 29 (NO. 23), 1989, P 170 5-1 721 40. N. TATEISHI, T.H. NORTH, AND R.T. WOODHAMS, ULTRASONIC WELDING USING TIE- LAYERS, PART I: ANALYSIS. 1989, P 164 9-1 654 17. A.J. POSLINSKI AND V.K. STOKES, ANALYSIS OF THE HOT-TOOL WELDING PROCESS , PROC. SPE 50TH ANTEC MEETING, 1992, SOCIETY OF PLASTICS ENGINEERS, P 122 8-1 233 Hot-Gas Welding: