Welding is a technique of joining widely associated with steel and other metals. However, is it restricted to metals or is it possible to apply this technique to other types of materials? The question is very common: is it possible to weld a plastic material? A short answer is to say that a plastic material is weldable. On the other hand, there are factors that need to be considered to determine which types of plastic materials are weldable. First of all, there are three different types of plastic materials:
Thermoplastics:
Is the term used for plastics that, when exposed to heat, will soften and eventually melt depending on the heating temperature. On the other hand, when cooling down, they will harden again and be back to their initial state and solidity. This is why they are defined as thermoplastics: they have the ability to be melted and shaped several times without changing their molecular structure. When the plastic material is softened by heating, it will melt and then, once cooled, take on a new solid shape and keep its mechanical and structural properties. This capability increases the possibilities in terms of plastic projects. Thermoplastics can often be reprocessed because they can be melted and shaped repeatedly.
Commonly Used Thermoplastics:
- Polypropylene
- PTFE (polytetrafluoroethylene)
- Nylon
- Polycarbonate
Thermosets:
Unlike a thermoplastic material, once a thermoset is melted and shaped, it can’t be reprocessed. Thus, once the thermosetting material gets its final shaped, it will no longer be possible to change its shape by heating it. Compared to thermoplastics, thermosets will not melt when heated at high temperatures, but rather achieve irreversible stiffness.
Commonly Used Thermosets:
- Phenolics
- Polyester
Elastomers:
These plastic materials are known for their elastic properties and their great ability of elongation. Therefore, they can be stretched significantly without being damaged, as they will be able to return to their original shape almost immediately. However, they have the disadvantage of being difficult to recycle.
Commonly Used Elastomers:
- Neoprene
- Rubber
Which Plastic Materials are Weldable?
As mentioned above, it is possible to weld a plastic material. On the other hand, only thermoplastics can be welded together. Thus, the thermoplastic materials include a wide variety of plastics that can actually be welded together.
To guarantee effectiveness and durability of plastic welding, it should also be noted that only two compatible plastics, i.e. two plastics from the same family, such as nylon with another nylon, could be welded together. A plastic welding made by following all the conditions will be durable and very resistant in addition to being aesthetic. The thermoplastics ability to soften will allow the cross-linkage between two pieces of plastics from the same family.
