Industrial Tools

Since plastic is easier to mould and form when it is sufficiently warm  and it melts when it is heated enough, this kind of materials is called thermoplastics.
this is the main difference with other materials, called thermosetting,  which, once moulded ,can’t melt anymore and can’t be remoulded.
There are thermoplastics which are more elastic and others which are less: for example, buttons of our keyboard,   are hard while plastic around a computer wires,  is usually softer.
This happens because all plastics have a precise temperature above which they become flexible and malleable   and under which they are rigid and fragile.
This temperature is called TG or glass transition temperature, and it is different for each kind of plastic.
At room temperature, some are under their TG, so they are rigid. Others are above their TG, therefore they are flexible.