Die Casting Versus Mold Manufacturing
There are many ways to manufacture parts for your business. Two of the most common are die casting and injection molding. Each process has advantages and disadvantages. Let’s have the experts at The Toolroom explain each process and help you decide what is best for your engineering needs.
Die casting’s process involves casting metal under extreme force. Metal is heated to its molten form and then remolded under high-pressure conditions. The process has been in use for almost three centuries. Non-ferrous metals such as aluminum, zinc or copper are the common raw materials used in die casting.
The four steps of die casting begin with die preparation when the mold cavity is sprayed with a lubricant and closed. Molten metal is then injected into the die under high pressure. This pressure is maintained until the liquid metal cools rapidly and takes the shape of the die. The die is then immersed in or sprayed with water to speed the cooling process. After cooling the die opens to eject and collect each shot. Note that shots and castings are not the same. A die can contain more than a single mold cavity. Each cavity has an individual casting. Each casting from a mold cavity is called a shot.
Die casting is most appropriate for manufacturing geometrically complex parts. Some advantages of die casting include its easy and quick production process and quality surface finishing that may eliminate the need for extra finishing. When precision and accuracy are important, die casting is a good choice, especially when there is a need for mass production of exact duplicates.
Die casting is not ideal for large parts, and is also entails expensive production costs for smaller scale jobs. Die casting is limited to using metals and alloys with a low melting point and is not ideal for alloys like steel that have high melting points. Finally, metal porosity might result from trapped air if a job is performed without necessary precautions.
Plastic injection molding is similar to die casting with the main difference being the medium utilized. Injection molding uses plastics and other polymers such as polyethylene, nylon, polypropylene and more. Plastic injection molding is the most common manufacturing process in use for fabricating plastics today.
Steps in plastic injection molding are virtually identical to those found in die casting. The mold is prepared by lubrication, as it allows for additional temperature regulation and allows for easier ejection of the part after the process is completed. The liquified plastic materials are injected into the mold at high pressure, and this pressure is maintained as the plastic cools and takes the form of the mold. A water spray or immersion in water speeds the cooling process. Once cooling is completed, the mold is opened and the part is ejected. The part can is then ready for any further processes such as finishing.
Plastic injection molding also has several benefits. It is a flexible process and can be used with a variety of plastics, resins and polymers in many colors. The process is fast, efficient and gives a smooth finish. It is better for the environment with almost zero waste of resources. Fillers can be added to the mold to increase the strength or other characteristics of your part. Parts resulting from plastic injection molding have excellent quality. Set up of plastic injection mold machines take time and expertise, but the end result is high quality and low-cost mass production of your parts. Plastic injection molding is utilized in the manufacturing of parts for electronics, automobiles, appliances and more.
The Toolroom is eager to educate our customers on the manufacturing processes available. For over 40 years, The Toolroom has provided the best in plastic injection molds, rubber injection molds, machining, and tool design. We work hard to be your partner in mold manufacturing. When its time to start your project, call us at (573) 437-4154 or send us an email.