What are thermoplastics?
Thermoplastics are plastic materials that become pliable or moldable when heated above a specific temperature and harden upon cooling.
What are the benefits of using thermoplastics?
- Light weight
- High strength
- Low processing costs
- Better fatigue properties than metals
What is plastic welding?
Several different methods of welding have been developed for thermoplastics. There are three factors to consider when welding thermoplastics:
Heat: Each thermoplastic melts within a certain temperature range. To begin welding, the surface of the thermoplastic material is heated to its melting point. For an optimum weld, it is important to stay between the minimum and maximum weld temperatures for the thermoplastic you’re using.
Pressure: After two thermoplastic materials are heated to their melting point, they are pressed together until they cool. The pressure applied to the material allows molecules in the two materials to mix, or reposition themselves. For an optimum weld, it is important to find the right balance of pressure.
Time: Different types of thermoplastics take a certain amount of time to melt and to cool. For an optimum weld, it is important to be knowledgeable about the properties of the material(s) you are working with.
What are the most commonly welded thermoplastics?
Polypropylene (PP). Industries like ducting and packaging use polypropylene coated fabrics for a variety of applications.
Polyethylene (PE). Agriculture and geomembrane industries have been welding polyethylene for years, but the sign industry has started to adopt this type of welding as well.
Polyvinylchloride (PVC). The awning, sign, banner, tent and ducting industries commonly use PVC laminated fabric.