Injection Molding Glossary
Purging Compound / Purging Pellet
A purge agent is a compound used for cleaning injection molding machines, typically during color or material changes. It helps to facilitate smooth transitions between different types of plastics, reducing downtime and improving production efficiency.
Compression Molding
Compression molding is a process distinct from injection molding, where plastic is heated and softened, then compressed within a mold to form parts of a specific shape and size. This method is commonly used for certain materials, such as thermosetting resins.
Injection Pressure
Injection pressure is the pressure used to inject molten plastic into the mold. If the pressure is too low, cavities may form in the part. Conversely, if it is too high, it can cause part deformation or mold damage.
Injection Molding
Injection molding is a manufacturing process where molten plastic is injected into a mold, cooled, and solidified. It is used across various industries, including automotive parts and household goods. By melting plastic and injecting it into the mold cavity, complex-shaped parts can be efficiently mass-produced.
Injection Molding Machine
An injection molding machine is a device used to perform the injection molding process. It includes various components such as heaters, nozzles, barrels, and clamping units, and is selected based on the specific requirements of the part being produced.
Injection Speed
Injection speed is the rate at which plastic fills the mold. If it is too fast, shear stress within the plastic increases, potentially causing part deformation or cracking. If it is too slow, cooling may begin prematurely, making proper filling difficult. This speed is a critical parameter for controlling the quality of molded products.
Insert Molding
Insert molding is a process where metal or other plastic components are incorporated into a plastic molded part. This enhances the strength and functionality of the component.
Weld Line
A weld line is a linear molding defect seen on the surface of a molded part, formed at the point where plastic flows converge from multiple directions. It can affect the strength and appearance of the part.
Ejector
The ejector is a device used to remove the finished part from the mold after molding is complete. The design and placement of the ejector affect the handling of the molded part and production efficiency.
Gas Assist Molding
Gas-assisted molding is a technique where gas (usually nitrogen) is introduced into the injection molding process. This allows for hollowing out parts, reducing weight, and lowering manufacturing costs.
Cavity
A cavity is the hollow section of an injection mold that shapes the exterior of the part. The dimensions and shape of the cavity determine the final dimensions and shape of the molded part.
Gate
A gate is the entry point where molten plastic flows into the cavity of the mold. The type and position of the gate significantly affect the appearance and properties of the part, so it must be carefully selected.
Core
The core is the part of the mold that shapes the internal features of the molded part.
Sprue
The sprue is the initial entry point where molten plastic enters the mold, connecting the nozzle to the runner. The design of the sprue is crucial as it affects the overall flow and efficiency of the injection molding process.
Molding Temperature
Molding temperature is the temperature at which plastic flows properly and fills the mold during the injection molding process. If the molding temperature is incorrect, it can lead to reduced part quality and production efficiency.
Two-Color Molding
Two-shot molding is a process where two different colored plastics are molded simultaneously. This allows for multi-colored designs, enhancing the appearance of the product.
Valve Gate
A valve gate is a specific type of gate that opens and closes through a valve, allowing precise control. It is used for manufacturing high-quality parts and processing specific plastic materials.
Barrel
The barrel is the part of the injection molding machine that melts, compresses, and injects the plastic into the mold. Proper control of the temperature and pressure within the barrel affects both the quality of the plastic and the efficiency of the molding process.
Family Mold
A family mold is designed to mold different parts at the same time using the same mold. This increases efficiency and reduces production costs.
Feeder
The feeder is a device that supplies plastic pellets to the barrel of the injection molding machine. Continuous and even feeding is crucial for the efficiency and consistency of the production process.
Runner
The runner is part of the injection mold, serving as a channel that directs molten plastic to different parts of the mold.