What Are the Types of Plastic Injection Molds Used in Manufacturing?

What Are the Types of Plastic Injection Molds Used in Manufacturing?

Plastic injection molding is a versatile manufacturing process, and the type of mold used has a significant impact on product quality, production efficiency, and cost. The choice of mold depends on product design, material properties, and production volume. Below is an introduction to the common types of plastic injection molds used in manufacturing, their features, applications, product examples, and technical requirements.

Types of Plastic Injection Molds

1. Single-Cavity Plastic Injection Mold

• Definition: A single-cavity mold produces one product per injection cycle.
• Applications: Suitable for low-volume production or complex, high-precision products.
• Product Examples: Medical devices, electronic casings, precision components.
• Compatible Plastic Materials: ABS, PC, PA (Nylon).
• Mold Materials: P20, 718 steel, suitable for medium lifespan requirements.
• Injection Machine Choice: Standard injection machines are sufficient; high-viscosity materials may require high-pressure injection machines.

2. Multi-Cavity Plastic Injection Mold

• Definition: Multi-cavity molds contain multiple cavities to produce several identical products in one cycle.
• Applications: Ideal for high-volume production, such as packaging components, bottle caps, or medical syringes.
• Product Examples: Bottle caps, cutlery, medical syringes.
• Compatible Plastic Materials: PP, HDPE, LDPE.
• Mold Materials: H13 or S136 steel, ensuring durability for high-volume production.
• Injection Machine Choice: Requires high-pressure injection machines; servo-controlled systems are recommended for efficiency.

3. Family Plastic Injection Mold

• Definition: Family molds include multiple cavities for producing different parts simultaneously.
• Applications: Suitable for products requiring multiple components, such as toys or electronic casings.
• Product Examples: Electronic device casing components, toy parts, appliance buttons.
• Compatible Plastic Materials: ABS, PC, PP.
• Mold Materials: 718 or NAK80 steel, suitable for medium-to-high lifespan multi-component molds.
• Injection Machine Choice: Servo-driven injection machines ensure uniformity across cavities.

4. Two-Shot Plastic Injection Mold

• Definition: Two-shot molds inject two different materials or colors into the same mold.
• Applications: Commonly used for toothbrush handles, medical devices, and automotive interiors.
• Product Examples: Toothbrush handles, buttons, automotive interior parts.
• Compatible Plastic Materials: PC+ABS, TPE+PP, PA+GF.
• Mold Materials: S136 or 718 steel, designed for high-precision and wear-resistance.
• Injection Machine Choice: Dual-shot or multi-shot injection machines ensure precise molding of two materials.

5. Insert Plastic Injection Mold

• Definition: Insert molds place a pre-formed part (e.g., metal insert) into the mold before injecting plastic.
• Applications: Common in automotive parts, electronics, and medical devices.
• Product Examples: Plug connectors, smartphone casing inserts, medical equipment handles.
• Compatible Plastic Materials: ABS, PC, PPS.
• Mold Materials: H13 or S136 steel for wear resistance and long lifespan.
• Injection Machine Choice: Specialized injection machines with insert placement fixtures.

6. Hot Runner Plastic Injection Mold

• Definition: Hot runner molds use heated channels to keep the plastic in a molten state.
• Applications: Widely used in large-scale, high-production applications.
• Product Examples: Bottle caps, disposable cutlery, medical packaging.
• Compatible Plastic Materials: PP, PE, PC.
• Mold Materials: S136 or 2316 steel, suitable for high corrosion resistance.
• Injection Machine Choice: Servo-controlled injection machines paired with hot runner systems for efficiency.

7. Cold Runner Plastic Injection Mold

• Definition: Cold runner molds use unheated channels to direct plastic into cavities.
• Applications: Suitable for cost-sensitive projects and a wide range of applications.
• Product Examples: Industrial parts, standard packaging boxes, plastic toys.
• Compatible Plastic Materials: ABS, PP, PE.
• Mold Materials: P20 or 718 steel, suitable for low-cost production.
• Injection Machine Choice: Standard injection machines are sufficient for small-to-medium batch production.

8. Prototype Plastic Injection Mold

• Definition: Prototype molds are temporary molds used for testing product designs.
• Applications: Suitable for R&D projects, small-volume production, and validating new designs.
• Product Examples: Small appliance casing prototypes, electronic component prototypes.
• Compatible Plastic Materials: ABS, PP, PLA.
• Mold Materials: Aluminum, ideal for low-cost, short-term use.
• Injection Machine Choice: Small standard injection machines are sufficient.

9. Gas-Assisted Plastic Injection Mold

• Definition: Gas-assisted molds inject gas into the cavity to create hollow sections in the product.
• Applications: Common in automotive, furniture, and large structural components.
• Product Examples: Automotive door handles, chair frames, gym equipment supports.
• Compatible Plastic Materials: PC, ABS, PP.
• Mold Materials: H13 or S136 steel, designed for high-pressure environments.
• Injection Machine Choice: Requires specialized gas-assisted injection machines.

10. Stack Plastic Injection Mold

• Definition: Stack molds have multiple layers of cavities, allowing for more parts per cycle.
• Applications: Best suited for high-volume production, such as packaging, bottle caps, and closures.
• Product Examples: Beverage bottle caps, food packaging containers, cosmetic containers.
• Compatible Plastic Materials: PP, PE, PC.
• Mold Materials: S136 or 718 steel, designed for high-load production needs.
• Injection Machine Choice: High-pressure, high-tonnage injection machines paired with automation systems for efficiency.

Why Choose SSB for Plastic Injection Mold Solutions?

Steady Stream Business (SSB) provides expert services tailored to various types of molds, covering the entire process from design to production. Whether you need single-cavity molds, multi-cavity molds, gas-assisted, or stack molds, SSB's advanced technology ensures efficiency and quality.

Contact Us

If you're looking for customized plastic injection mold design and manufacturing solutions, contact SSB today! Our tailored services will help you enhance production efficiency and reduce costs.