What Are The Types of Injection Molding?

Conventional Injection Molding

This is the most widely used form of injection molding. It involves injecting molten plastic material into a mold cavity under high pressure, allowing it to cool and solidify before the mold opens and the part is ejected.

Insert Molding

Insert molding involves the addition of molten material into a finished product, often containing multiple components. This technique enhances product strength and reduces weight compared to other methods.

Overmolding

Overmolding involves applying an injection mold onto another substance to enhance product durability. By adding molten material, such as thermoplastic elastomer (TPE), on top of an existing material, the product's structure and quality are improved.

Two-Shot Molding

two-shot molding is a process where two different materials or colors are sequentially injected into the same mold to create a single part. This allows for the production of complex parts with multiple colors, materials, or textures without the need for additional assembly steps.

Liquid Silicone Injection Molding

Liquid silicone injection molding replaces thermoset plastics to produce desired molds. This technique involves subjecting liquid silicone to high temperatures, which then solidifies into a permanent mold. Once formed, the mold cannot be reverted back to a liquid state. Liquid silicone injection molding is commonly used for medical devices and other applications requiring high precision.

Thin Wall Molding

Thin wall molding is employed to create plastic products with extremely thin walls. However, the use of thin walls can sometimes result in cracks and compromises in the product's quality and performance. To ensure successful thin wall molding, meticulous attention to detail is required in mold design, part design, and overall process execution. This technique finds applications in the manufacturing of tubes, vessels, and electronics.

Gas-assisted Injection Molding

Gas-assisted injection molding is employed to prevent deformation and ensure the integrity of plastic products. By injecting gas into the mold, the plastic material is supported, allowing the exterior to remain smooth and free from deformities. The interior, however, is hollow as needed. This technique reduces material usage, resulting in cost savings during production.

Micro-Injection Molding

Micro-injection molding is used to produce extremely small and precise plastic parts, typically with tight tolerances. It requires specialized equipment and precise control of injection parameters to produce miniature components used in industries such as electronics, medical devices, and telecommunications.

3D Printing

3D printing plays a crucial role in the injection molding process, allowing businesses to create prototypes for client approval. By visualizing the injection mold through 3D printing, clients can assess the final product's appearance and make necessary adjustments. As prototype molding technology advances, the ability to print actual plastic and metal injection molds will become a reality.

Family Mold

Family mold injection involves attaching two or more mold cavities to a single base. This technique allows for simultaneous creation of multiple molds, streamlining production. Alternatively, one cavity can be used at a time to produce molds. Care must be taken to ensure proper separation of mold cavities if molds are created simultaneously. Consistent specifications are necessary when producing molds concurrently.

Hot Runner Molds

Hot runner molds optimize the mold cycle by utilizing a manifold with controlled temperature. By reducing scrap cycles and material wastage, hot runner molds offer cost savings during the molding process. Temperature control systems are essential to maximize the benefits of this technique.

Cold Runner Molds

Cold runner molds are a traditional method that utilizes sprues in the mold cycle. While this method results in longer molding cycles and more material waste, the wasted material can be recycled and mixed with future plastic pellets. Care must be taken to ensure the quality of the recycled material to maintain the finished product's integrity.

Unscrewing Molds

Unscrewing molds are ideal for creating threaded holes in plastic parts. This automated process incorporates drives and threading technology to achieve the desired look. Threads can be created both internally and externally, providing versatility in design.

Insulated Runner Molds

Insulated runner molds mimic the hot runner injection molding technique using tools similar to those found in cold runner molds. The use of cartridge heaters and heat production tools allows for insulation of the molten material, reducing costs compared to traditional hot runner molds. However, this technique may not be suitable for all materials.

Thermoplastic Injection Molding

Thermoplastic injection molding employs thermoplastic polymers that can be melted down and solidified repeatedly. This technique provides flexibility, allowing for multiple molding cycles.