 Hello friends, myself, Dr. N S. Katikar, Assistant Professor, Department of Mechanical Engineering, Valachandra Institute of Technology, Solapur. Today, we are going to see the presentation on Welding of Plastic Part 4. The learning outcome of this presentation. At the end of this session, the student will be able to understand the need and importance of welding of plastics. Student will be able to apply welding technique in real time. The content for this presentation, it flows likewise. Introduction, need of welding of plastics, classification of plastic welding, high-frequency induction welding. We will discuss one of the type high-frequency induction welding. In the introduction, let us see some of the points related to the plastic material, need of plastic material products, plastic part manufacturing categorization and so on. As we know, for particularly any product survival in their respective environmental condition, the many properties and characteristics are the important and critical one. One of the same is the material. The product is going to be efficiently handled and working out in the respective environmental condition and it can be optimized with the proper selection of material. In consideration with many characteristics, behavioral properties and many things, the material is going to select for the particular product. Nowadays, as the advanced kind of material, the hydrocarbon polymers rather plastic material is going to be used for product design. The plastic material products is the need of the time which delivers the many advantages which are the reflecting properties of plastics like non-conductor of electricity, non-corrosive properties, easily moldability and so on. Whenever the plastic part manufacturing is going to be considered, it can be produced by as a single part in visual singular element and further it is required to be assembled for the respective fulfillment of the requirement. Need of welding of plastic. As we seen over here summarizingly, it goes for the various applications like assembly, repair and maintenance, packaging, dissimilar material joining and to fulfill the many needs of the situations. Joining of the plastic goes with the various particularly technique, mechanical joining like using the fastness, nut, bolts, screws, pins, rivets. It goes with the adhesive bondings like particularly chemical adhesives are used for joining the two distinct plastic materials and the third one which is our topic that is welding. With the means of intentional addition of heat energy, pressure, filler material, the welding can be fulfilled for the plastic material. At this stage of this session, I am going to ask one of the question, are you able to recall share some of the application of welding of plastic joints which you had seen or come across earlier anywhere in real time environment. Just think about an enlist. Thank you. I suppose that you had enlisted the various applications you had come across regarding the welding of plastic. Let us go with the classification of plastic welding. Welding processes are classified by two distinct means, external heating, internal heating. External heating where the convection and conduction of heat energy is going to be applied as a concept over there for the fulfillment of welding. Whereas internal heating, the conversion of mechanical energy into the heat energy through the surface friction and so on where the internal electromagnetic heating, internal mechanical heating, ultrasonic friction, laser and so on types are there. Out of that, let us go with the discussion about the first one of the type, high-frequency induction welding. High-frequency welding also known as dielectric sealing or radio frequency. Heat sealing is a very mature technology that has been seen around since the 1940s. High-frequency electromagnetic waves in the range of radio frequencies can hit certain polymers up to soften the plastic for joining. Heated plastic under the pressure weld together, heat is generated within the polymer by the rapid reorientation of some chemical dipoles of the polymer which means that the heating can be localized and the process can be continuous. When an electrical insulator like a plastic is embedded with a material having a high electrical conductivity like metals or carbon fibers, induction welding can be performed. The welding apparatus containing an induction coil that is energized with the radio frequencies. Electric current, this generates an electromagnetic field that acts on either an electrically conductive or ferromagnetic workpiece. It is an electrically conductive workpiece. The main heating effect is resistive heating which is due to induced current called AD currents. Induction welding of carbon fiber reinforced thermoplastic material is a technology commonly used in for instance the aerospace industry. Let us see the various setups, conceptual diagrams for high-frequency induction welding. You can see over here how the particular tube can be manufactured with the high-frequency induction welding. Two pressure rollers are there. You can see to the cursor, pressure roller one, pressure roller two. Welding seam is to be likewise and the preformed bend of sheet metal is passed through the particularly pressure rollers. Here you can see that sliding contacts are there. For the fulfillment of particular requirement, V angle 4 to 7 degrees created over there. Tube is going to travel. It is feed to the pressure roller. You can see the tube travel. Impedre is there which is supporting for the particular welding process. Whenever the current is passed through the same electromagnetic field is going to form which is exerting the heat energy which cause for melting of adjacent area and due to the pressure the welding rather the seam welding is possible. You can see the another conceptual diagram or setup. In the previous setup we had seen the flat sliders are there. Here you can see that induction coil is there, induction coil where the induction coil is bound rather the preformed bend of sheet metal is passed through the induction coil and as it goes forward the particularly welding rather seam welding is possible as like in previous case. Some of the examples or conceptual figures for high-frequency induction welding. Tube butt seam welding. One is with the flat, another with the induction coil. Tube mash seam. You can see that at the top corner it is going to be lap. It is going to be lap. Here it is butt. Here it is a lap. A little bit lapping and high-frequency is applied over here and tube mash seam is there. Strip butt and T joints. Another examples. You can see that strips are also can be weld in a butt form. T joints, two distinct sheets can be joined at an right angle. Spiral tube. With the sheet metal you can make the tube by wounding its spiral direction. Another one is you can see that spiral tube fins. The fins can be applied over the tube. Fins can be applied over the tube. Another one projection seam. Here you can see the geometry how the welding can be done. Pipe butt. Two distinct pipes can be joined together with the induction coil placement over there. Bar butt. You can see here bar butt. Two distinct bars can be joined together in a butt joint form. How exactly the induction coils are looking like? The copper tubing or the bars are likewise. Normally these are water cooled surrounded one. You can see that the hollow particularly tubes are there through which water can be circulated. The advantages of high-frequency induction welding produce welds with very narrow heat affected zone, high welding speed and low power consumption, adaptable to many metals and high efficiency. Limitations. Few of the limitations are likewise. Hazardous of high frequency current is considerable limitation. Uneconomical products required in a small quantity. And special care to be taken to avoid the radiation interference in the plant vicinity. Applications are material commonly welded using technology or nylon, PET and so on. Some of the references for particular our presentations are as follows. Thank you. Thank you.