The Blow Molding Process

THEORETICAL BACKGROUND Blow molding is a fabrication process to convert the raw materials (resin) into finished hollow containers (products). It is a manufacturing process by which hollow plastic parts are formed. Principle of the Most Basic Type of Blow Molding 1. Resin is melted by heaters and plasticized by an extruder. 2. Then it is extruded so that it forms a tube-shaped parison matching the size of the product as it passes through the die. 3. Air is then forced into the parison and press it against the inner walls of the mold. After the parison cools and become solid in the mold, the air is released. 4. Finally, the mold will open and the product is deflashed and ejected or taken out the machine. Higher Institute for Plastics Fabrication WORKBOOK for Extrusion Blow Molding Practical Course Prepared by Extrusion Blow Molding Department 1st Edition 2009