The economics of plastics processing is determined by the type of process. Plastics can be processed with the following methods: machining, compression molding , transfer molding , injection molding , extrusion , rotational molding , blow molding , thermoforming , casting, forging, and foam molding . Processing methods are selected based on equipment cost, production rate, tooling cost, and build volume. High equipment and tooling cost methods are typically used for large production volumes whereas low - medium equipment cost and tooling cost methods are used for low production volumes. Compression molding, transfer molding, injection molding, forging, and foam molding have high equipment and tooling cost. Lower cost processes are machining, extruding, rotational molding, blow molding, thermoforming, and casting. Aspect of Plastic Processing Degradable plastics Oxo-degradable plastics: these are petroleum-based plastics with additives such as transition metal