In the plastics industry, the four broad areas of processing arepolymerization,conversion,finishing, andrecycling1.Polymerization is the process of creating plastic resins from monomers or pre-polymers, using chemical reactions such as addition, condensation, or ring-opening2.Conversion is the process of transforming plastic resins into plastic products, using various methods such as injection molding, blow molding, extrusion, rotational molding, and thermoforming3.Finishing is the process of adding value to plastic products, such as coating, printing, welding, or assembling4.Recycling is the process of recovering plastic waste and converting it into new plastic products or raw materials, using mechanical, chemical, or biological methods5. Therefore,manufacturingis not one of the four broad areas of processing in the plastics industry, as it is a general term that encompasses all the stages of producing plastic products from raw materials.References:
Plastics Manufacturing: Types of Plastic and Processes - Deskera
Plastics industry - Wikipedia
Methods of Processing Plastic - Plastics Industry
Plastic recycling - Wikipedia
Polymerization - an overview | ScienceDirect Topics