What are the Characteristics of Polyvinyl Chloride (PVC)?
Some of the most significant properties of Polyvinyl Chloride (PVC) are:
1.Density: PVC is very dense compared to most plastics (specific gravity around 1.4)
2.Economics: PVC is readily available and cheap.
3.Hardness: Rigid PVC is very hard.
4.Strength: Rigid PVC has extremely good tensile strength.
Polyvinyl Chloride is a “thermoplastic” (as opposed to “thermoset”) material which has to do with the way the plastic responds to heat. Thermoplastic materials become liquid at their melting point (a range for PVC between the very low 100 degrees Celsius and higher values like 260 degrees Celsius depending on the additives). A major useful attribute about thermoplastics is that they can be heated to their melting point, cooled, and reheated again without significant degradation. Instead of burning, thermoplastics like polypropylene liquefy, which allows them to be easily injection molded and then subsequently recycled. By contrast, thermoset plastics can only be heated once (typically during the injection molding process). The first heating causes thermoset materials to set (similar to a 2-part epoxy) resulting in a chemical change that cannot be reversed. If you tried to heat a thermoset plastic to a high temperature a second time it would simply burn. This characteristic makes thermoset materials poor candidates for recycling.