This video will explain you that how the plastic injection molding works.
Plastic injection molding is the method which is mainly used to manufacture parts of thermosetting also thermoplastic materials. In this molding work, the scrap material is put into a box. temperature is given to that box so as to get a plastic design.
Plastic injection molding is generally used to manufacture car parts, and can be utilized so as to get large car parts as well as small parts.
The essential difference is that thermoplastics remain permanently fusible so that they will soften and eventually melt when heat is applied, whereas cured thermoset polymers do not soften, and will only char and break down at high temperatures. This allows thermoplastic materials to be reclaimed and recycled.
The reason for this is that thermoplastics have relatively weak forces of attraction between the chains, which are overcome when the material is heated, unlike thermosets, where the cross-linking of the molecules is by strong chemical bonds. Effectively the thermoset is one large molecule, with no crystalline structure.
Compared with thermoplastics, thermosets are generally harder, more rigid and more brittle, and their mechanical properties are not heat sensitive. They are also less soluble in organic solvents.