Plastic molding is the process of making various forms (powders, pellets, solutions and dispersions) of plastics into articles or blanks of desired shapes. There are as many as thirty kinds of molding methods.
The choice of plastic molding is mainly determined by the type of plastic (thermoplastic or thermoset), the starting form, and the shape and size of the product. Commonly used methods for processing thermoplastics include extrusion, injection molding, calendering, blow molding and thermoforming. Thermosetting plastics are generally processed by molding, transfer molding, and injection molding. Lamination, molding and thermoforming are the shaping of plastics on a flat surface. The above plastic processing methods can be used for rubber processing. In addition, there are castings using liquid monomers or polymers as raw materials. Among these methods, extrusion and injection molding are the most used and the most basic molding methods.