In modern manufacturing, ontology provides a standardized and structured way of organizing and sharing information. It enables better communication and collaboration between different entities involved in the manufacturing process. Acknowledging these benefits, we establish an ontology for manufacturing plastic components using the Industrial Ontology Foundry (IOF) framework. The IOF framework, derived from the Basic Formal Ontology (BFO), is an essential component of smart manufacturing. It facilitates semantic integration, enabling data exchange and reuse between different systems and organizations in the existing IOF framework. Our research employs a case study approach to develop the ontology for plastic manufacturing, which involves two main operations: sheet extrusion, and thermal forming operation, each with specific sequences of processes that must be followed to produce the desired final products. Our goal is to integrate the necessary process steps into the existing IOF framework in plastic manufacturing. To achieve this, we utilized Protégé software version 5.5 and used ontographs to visually depict the relationships between different categories and subclasses. By doing so, we aim to showcase how ontology reasoning can be applied effectively in the manufacturing sector. This will demonstrate the practical use of logical inference and computational techniques, ultimately improving the overall manufacturing process.