The molding process is used to shape a plastic in the desired shape. There are several processes to perform. Plastic is a synthetic material that gets semi-liquid on heating. To set it into a particular shape, it is firstly heated up and then placed in the mold. After cooling down it is taken out from the mold and it is in the desired shape.
Depending on the desired shape and other qualities, various molding processes are used to shape plastic.
Plastic Molding Using Casting
Plastic molding using casting is one of the simplest methods to get a desired shape of plastic without getting into any complexity. In this process, plastic is heated to turn it into a fluid state and then put it inside a mold. After some time when the plastic cools down, the mold is removed. This process is used to make complex shapes with much clarity.

Injection Molding of Plastic
Injection molding creates high-quality 3-D shapes that can be reproduced commercially. It starts melting the plastic in a hopper and then injecting it in a closely tight chilled mold. In this process, plastic instantly takes the shape of the mold. Once, the process is completed the mold is opened and the object is released. The mold can be used multiple times before there is any need to replace it. The most common objects that are created in this molding process is butter tubs, yogurt cups, plastic toys, bottle caps, etc.
Rotational Molding of Plastic
In this molding process, molten plastic is added from inside to create an object. Mold is held by two mechanical arms that rotate it constantly at the same level. The molten plastic is flown to form an inside layer of the object due to rotational force. The common example of this process is Toys, shipping drums, storage tanks, and consumer furniture.
Blow Molding Plastic Manufacturing
It is different from injection and casting molding. It is used to create objects that need to be hollow from inside. The common example of this process can be a water bottle. When molten plastic is put into the mold, there is an additional tube set inside the mold which gets particular shape when inflated. So, when molten plastic is fed into the mold, the tube inflates and plastic gets the shaped between the mold and the inflated tube. The plastic is left to cool down and then removed.

Compression Molding of Plastic
Compression molding is a complex manufacturing process. It is generally used for large scale production. It is a labor-intensive process where molten plastic is poured into the mold and the second mold is pressed against the first mold. The plastic gets into the desired shape between the molds and it left to cool down. This process is used for the manufacturing of tires, boat hulls, etc.