Injection molding and CNC machining are processes that require careful planning and skill to make quality products. CNC machining is a subtractive process that removes layers of material from solid blocks following computer commands. Plastic injection molding is a pressure-driven process that forces liquid plastic into steel molds, which quickly cools and is ejected for production.
Drilling
Drilling is a subtractive process where a drill cuts materials into pieces. It can create holes, pockets, or curves in metal parts. It also produces chips that are often thrown away from the workpiece. CNC machining for injection molds offers benefits, but the cost per part will differ depending on the type of project you are working on and how quickly you need your custom parts. For example, injection molding lead times can be much longer than CNC machining due to the need for a mold. The critical difference is that CNC machines use a digitalized computer to automate, monitor, and control the movement of factory machinery. This helps to eliminate human error and reduce the time needed for production.
Milling
Milling is removing material from a solid block of material using computer-controlled cutting tools. The machining process is guided by a digital file that can be altered between production runs, similar to how injection molding works. The advantage of machining is that it can produce complex parts that would be impossible or very difficult to make with injection molding. This includes features like living hinges, deep holes, and square edges. CNC machining has significantly lower lead costs than plastic injection molding, which requires a significant upfront investment to fabricate a multi-cavity mold. This makes it an excellent option for high-volume production projects. Additionally, machining can produce tighter tolerances than injection molding. But that does come at a price — substantial material waste.
Grinding
CNC machining is often used to create custom parts requiring precision and tight tolerances. Using a CNC machine to complete the job requires a machinist to understand several critical aspects of the process, including feed, depth of cut, and spindle speed. A machinist can control all of these factors using the CNC machine’s software. The software also helps to create a 3D design of the product so that engineers can verify that the design will work as intended. Unlike injection molding, which uses thermoplastics, CNC can make parts from various materials, including metals. This allows for much more flexibility and versatility in the manufacturing process. However, it’s important to remember that CNC is only as good as the person operating it.
Sinker EDM
Electrical discharge machining (EDM) is non-traditional, subtractive manufacturing. It consists of an electrode and workpiece submerged in an insulating fluid such as oil or other dielectric liquids. As the electrode approaches the workpiece, an electric spark jumps between the two and cuts away material. Graphite, copper, brass, and copper-tungsten are common electrode materials for EDM. Graphite is easily machined and offers high wear resistance, but is expensive. Injection molding is a popular method of producing custom parts for various industries. It’s an ideal option for large-volume production with tight tolerances, and it can be used alongside CNC machining to produce the most precise part possible. This combination is also helpful for prototyping. It allows manufacturers to test and refine the design before committing to production.
Water Jets
Water jet cutting is a powerful, precise way to cut almost anything with extreme accuracy. It uses high-pressure tubing to get the water to a nozzle, which either sprays pure water or mixes in an abrasive to increase its cutting power and strength. Unlike injection molding, which uses heated and stretched plastic sheets to make parts, CNC machining does not require heat to shape the material. This means that complex parts with angled walls and various shapes can be easily created with this process. The product’s initial design is created using a CAD software program and then converted to a file that the CNC machine can understand. The machine then removes the material from a layer to create the part. Read more exciting articles on Tech new master
