Possible causes of failures in the extrusion welding In Arístegui Maquinaria we know that at the moment of performing a welding, it must be taken into account many aspects. Nobody wants to perform a welding that soon will break or will not be as it was expected. To you obtain a welding without failures it is not a matter of lucky, because first you must perform a series of steps to avoid the causes which produce these failures. Well, which causes can produce failures in the extrusion welding? There are 5 main causes which you must avoid under any circumstances: Bad collocation or wrong setting of the pieces to be welded. Not scratching or wrong scratching of the area that you are going to weld. Not keeping a proper speed of the welding. To mistake the election of the nozzle. To have worn-out Teflon. Before starting, we want to do a brief section and remember you that the extrusion welding of rod has many applications within the sector of the plastic welding and if you are interested, you can discover them through the following link: (http://bit.ly/ZxZ1La) And now: Which causes produce failures in the extrusion welding? Bad collocation or wrong setting of the pieces to be welded When we are going to weld with rod, the pieces that we want to weld must be well-placed. We can’t have, for example, two plates to do a corner and which don’t have the correct angle or which aren’t well-adjusted and there are cracks. To avoid this problem, we have two options: To adjust the pieces with force by using tools… or a worker who keeps them joined while another one welds with the extruder. This method requires a higher work, as it is needs two workers. To use a manual welder and tap the pieces where we are going to weld them, so in this way we make sure that they are kept together while we are welding with the extruder. For cases in which the plates are of a higher thickness, it is recommended to weld first with a rod of 3 or 4mm with a manual welder, as tapping the so large plates maybe it has no the effect we want. If you want more information about the manual welders, you can find it in our website: http://bit.ly/1r8Ci1v Not scratching or wrong scratching the area you are going to weld This is a common problem as many people think that it is little datum without any importance and it is wrong. The plastic during the process of fabrication acquires an external layer of oxidation (that’s why the plastic bights). When it is welded plastic plates, pipes… it must be scratched the area where you are going to join to make sure that there is no oxidation and so the materials will be well-welded. To scratch the layer, in Arístegui Maquinaria we have some tools indicated for that (fittings for welding with rod and extrusion). Not keeping a proper speed of welding Here there are two problems: that you go too slow or too fast. If you go slower than the normal speed, you will probably burn the plate which you are going to weld and so you will not correctly weld the rod and the plate. If the speed that you take is faster than the necessary one, you will not hit properly the material you want to join and therefore, neither you will get the pieces welded. Which is the solution? You must watch that the paste (melted plastic) never goes out in the front side of the nozzle, as if it happens it means that you are going too slowly and you must hurry up. And if you go too fast you will realise that you are not filling completely the hole where you are placing the rod and you must go slower. To mistake with the election of the nozzle There are 4 main different ways of extrusion welding. The Film Weld, V Weld, Fillet Weld, external Corner Weld and the X Weld. For each type of welding, there is a different nozzle (except the welding in V and X shape that it is the same); it is essential to use the indicated one because in that way we will never place the rod in the necessary place. To have worn-out Teflon The Teflon is a soft material that with the daily use starts to worn out and to lose its original shape and therefore, its efficiency. A nozzle with the worn-out Teflon is very likely to produce malformations in the welding and it will not have the necessary quality. To avoid this kind of problem, you must only check that the nozzle is in good condition and if it isn’t, you must change for another one. To finish, you will have to check the quality of the welding and if it has failures. For that, you can use destructive methods and non-destructive methods (igniter). And you must also remember that the plastic can be only welded each other, the different plastic repel each other so for extrusion welding you will need the rod of the same material like the piece you want to weld. By nuevoaristegui|2017-05-07T03:28:24+00:00October 15th, 2014|Recent news, Technical information, Aristegui Maquinaria news, Extrusion and rod welding, Sector news|0 Comments Share if you liked! FacebookTwitterLinkedInGoogle+Email Related Posts Leer articulo Why the hot air welding is the most indicated to repair a tauliner? Why the hot air welding is the most indicated to repair a tauliner? Leer articulo The use of PVC pipes for wastewatertreatment The use of PVC pipes for wastewatertreatment Leer articulo Benefits of the use of TPO roofs for waterproofing Benefits of the use of TPO roofs for waterproofing Leer articulo Which are the steps of the socket welding? Which are the steps of the socket welding? 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