Welding

5 Pages 1165 Words

Plastic & Metal Welding Processes


“In plastics welding, films are fused together under action of heat and pressure, resulting in cross linking of their molecular chains.”(T.I.S.-Plastic welding processes) It is very similar to the way that metal is welded together. Instead of gas, metal and electricity the plastic processes use various types of heat and pressure.
In a process called Hot Gas Welding, hot air melts the plastic films and they are put together. When they are cool the hot air made the molecules mix-up and fuse together. A very low efficiency level and high losses of energy are major down falls in Hot Gas Welding.
Another process used to weld some plastics, is one called Contact Welding. In this process the films are heated, pressurized by pincers, resulting in a low efficiency weld, because only the outside of the films get heated and welded. This process can only make small welds.
Impulse welding isthe same as Contact Welding, only that in Impulse Welding you are able to adjust the heat that is imposed into the film.
High Frequency Welding is another form of a Plastic Welding Process. In High Frequency welding high frequency waves travel through the plastic. When this is done it make the electrons move really fast, thus making the plastic heat up. Then you pressurize the plastic and you have your weld. This process is very efficient; it can be welded in small precise areas or in large areas as well. “High frequencies excite the chemical structure of plastics with neutral or atoms containing both a negative and positive electrons.”(T.I.S.-Plastic Welding Processes)
Welding is a craft that can be preformed reasonably by amateurs. As always, good equipment is important for producing good work.”(Garnett, Roger - I.W.P.E.)
In metal welding a filler rod is melted by electricity, materials need to be similar, and a shield gas of some sort is usually used.


The MIG/MAG process is an easy method of...