The method of plastic injection molding is an exceptional industrialized system. The material of injection molding is used to formulate parts from plastic materials. The processes of molded pieces are contrived from thermosetting plastics and thermoplastics. It is consisting of three main parts including the injection units, the mold plus and the clamping. A basic procedure of injection molding is heat-softened plastic material and forced from a cylinder to a cool cavity. It is typically used for manufacturing technique. The mold is made from precision-machined, a metal, aluminum and either steel materials. Nowadays, the part of plastic injection molding is widely used for different kind of parts including the smallest component to entire body panels of cars. There are number of advantages provided for injection molding such as running cost may be high, little need to finish parts after molding, expensive equipment molding, low labor costs, high tolerance are repeatable and even minimal scrap losses. The industries of plastic molding have been producing an array of products for different kind of industries like plumbing, medical, construction and aerospace. The plastic injection molding is sometimes called as CNC plastic machining. It is very reliability as well as durability. It is often referred to be several processes of fabrication. The fabricating plastic parts are commonly operated by CNC machining. They are controlled by technology like via computer software controls. The use of CNC machining is typically useful in many applications within medical or fluid handling and error free. It was first established by 1930s. It is only producing mass products that we use every day. Another good example of sunglass accessories are used to create mold injection. It is only created for frames and lenses. It is an expensive material. In recent years, the plastic molding injection comes to a close with assembly taking place in India and Mexico.