The plastic extrusion blow molding machine is the tool used to make plastic botles. The tool involves a parison which is a hollow tube through which air is passed through and a mold in the shape of the plastic part you are making. Air is forced through the parison into the mold where there is molten plastic. The air then inflates the plastic. After the plastic hardens, the mold can be taken apart and the plastic piece can be taken out.
Injection blow molding is a process that is used in making smaller, mass produced parts --- for example, small mobile phone parts or buttons. The tool for injection blow molding involves nozzles, an extruder barrel and a mold. The extruder barrel melts the plastic before injecting it through the nozzles that lead to a mold. The tool for this process involves a lot of pressure as plastic is still quite thick in its molten state.
The stretch blow molding technique is essentially a continuation of the previous two molding processes but it involves a different tool. The point of a stretch blow molding tool is to harden the plastic so it can be used in highly pressurized situations, such as to hold carbonated drinks. The machine does this by heating up the plastic and stretching it with a tool called a core rod.