When it comes to producing end-use parts and products, one material stands out the most: Plastic. There are thousands of polymer options, each with specific mechanical properties. They make almost everything and there is a variety of plastic manufacturing processes that convert plastics into products. But manufacturing options can be very limited and should be treated case by case. For example geometry and design require significant design for manufacturing (DFM) optimization.

1. Blow Molding: By inflating a heated plastic tube (called parison) inside a mold we can create a hollow plastic part. This type of manufacturing process operates at far lower pressure than injection molding. It has a lower tooling cost than injection molding. Blow molding is the most common process for creating plastic bottles, toys, automotive parts etc.

2. Extrusion: Machinery for this process is relatively cheap as less complex. Extrusion is almost a continuous process, which makes the price of products very low. Products that are most commonly made by extrusion are pipes, straws, hoses and window frames. Plastic is pushed through a heated chamber by a screw, then forced through a die that creates a final shape of the part. The extruded plastic is cooled then spooled or cut into desired lengths.

3. Injection Molding: Molds for this process are highly complex and due to the high temperature and pressure involved these molds are made from metals like hardened steel. The mold is closed by hydraulic press, then small plastic pellets are melted and extruded by a screw. The molten plastic is then injected into a mold. The part is then cooled into the mold to solidify enough to be ejected, and at the end sprues, runners, and flash are removed from the part.

4. Vacuum Forming: Vacuum formed plastic products are common: product packaging, shower trays, car door liners, boat hulls, etc. Tooling cost for this process is low compared to other olastic molding techniques. Molds are made from wood, plasters, and 3D printed resins, but for high production volumes metal tooling can be used as well. In this process plastic is stretched over the mold while vacuum is activated to suck the air out between the plastic and the mold.

5. Rotation Molding: Rotation molding is also called rotomolding, and it is used to produce mainly large hollow objects. Rotomolding creates parts with nearly uniform wall thickness. The cost of the parts are very low relative to the size of the part. It is ideal for short-run production or as an alternative to blow molding for lower volumes.

6. Polymer Casting: In this process, molds are made form latex rubber or room temperature vulcanized silicone rubber, but only a limited number of parts can be produced (usually, between 25 to 100). This molds can reproduce even the smallest of details. Polymer casting is typically used for prototyping and short productions.

7. CNC machining: Computer numerical control (CNC) machining is unique process where material is removed by a spinning tool from a fixed part. This is ideal for low volume plastic part applications that require geometries that are difficult to mold. The process can produce high-quality plastic components with short lead times. The cost per part increases with part complexity.

8. 3D Printing: Three-dimensional printing process is generally slower and for some printers it takes days to print complex parts. As this process keeps improving, the cost per part continues to drop. This type of production requires no tooling and only a minimal setup time for a each new design. It can create three-dimensional parts directly from CAD (computer- aided design) models by building material layer by layer until is complete.