Understanding the Differences Between Injection Molding and Transfer Molding
Injection molding and transfer molding are some of our core manufacturing services here at HLH Prototypes. Both processes are popular for plastic manufacturing, but they have distinct differences that could influence your choice of method for a project.
The process
In transfer molding, a screw feeds the material into a heated chamber before a plunger forces it into the mold cavity. Meanwhile, injection molding melts and injects the material with a reciprocating screw into the mold cavity.
Applications
Transfer molding is often the preferred manufacturing option for low-volume simple molds and encasements. Meanwhile, injection molding is best for larger parts with thin walls, usually cubic, cylindrical, or three-dimensional, with complex features. This is because it is more precise and has higher production rates, while transfer molding is known for having low tooling complexity.
Manufacturers typically prefer injection molding over prototype machining for producing plastic housings, consumer electronics, household appliances, automotive interiors, and power tools. This manufacturing technology is also ideal for producing open vessels (e.g., buckets), household products (e.g., toothbrushes), medical devices (e.g., valves and syringes), and plastic toys.
Meanwhile, transfer molding is usually used to encase electronic components with plastic or rubber. The process allows inserts like ceramics, semiconductor chips, or metal prongs to be placed in the mold before injecting the material, allowing it to float within the resin during curing. It’s also practical for making connectors, molded terminals, studs, and pins.
Speed and cost
In transfer molding, the raw material needs to be prepared before being introduced into the mold. This means extra labor, processing times, and additional costs. Injection molding is more straightforward because it instantly mixes and prepares the material for immediate use.
What should you use?
Learn more about prototype machining, injection molding, and transfer molding by talking to our experts here at HLH Prototypes. We can also review your project at no cost and give tips and suggestions to help you pick an appropriate manufacturing method.