Insert molding is a form of injection molding that involves placing a preformed metal or nonplastic material inside a custom mold, which is then overmolded with molten plastic. This forms a single, bonded piece that can help reduce assembly costs and improve part reliability. It’s particularly useful for manufacturing complex parts that would be difficult or impossible to create using other production methods such as soldering, adhesives or fasteners.
Many different types of materials can be inserted into plastic through this process, but they are most commonly made from brass, stainless steel or aluminum, along with a variety of threaded components such as bushings and sleeves. The insert can be positioned anywhere in the finished product, from a threaded hole in the center of an electronic component case or medical instrument to a handle or dial screwed onto a threaded stud. It’s a common technique used in automotive and other industries to create products that require metal-to-plastic bonding, such as electrical sensors, gears, handles, knobs and fasteners.
The benefits of insert molding include the ability to make stronger and more durable plastic parts by combining them with metal. It also helps to minimize assembly costs, which can be expensive and lead to delays in shipping and assembling the final product. Using this process can reduce the size of the overall product, which can be beneficial for reducing weight or making it easier to transport or store.
Because the metal and plastic are bonded in one piece, insert molding can eliminate or greatly reduce the need for soldering or other types of joining methods. This can help reduce manufacturing costs, and it can also make the final product more reliable by averting loosening, improper terminations or misalignment of components. It can also increase the resistance to vibration and shock.
It’s important to note that a successful insert molding project requires careful planning, as any flaw in the design of the insert can lead to costly errors during the production process. It’s important to consult a skilled and experienced team of engineers and manufacturers who can help ensure that the proper materials and process are used to get the best results.
At Proto Labs, we use a variety of manufacturing processes, including CNC machining and 3D printing, to provide customers with fast, low-cost prototypes. For more information on how we can help with your next insert molding project, contact us. Our PolyJet 3D printer, which uses photopolymer for elastomeric and overmolded parts, can produce prototypes in days or even hours. Learn more about it here. You can also download our infographic on injection molding and rapid prototyping. It has all the basics you need to know about these two processes, including the most popular types of materials and designs that can be incorporated into your finished product. It’s a great resource for beginners who want to understand more about how these processes work together. insert molding