Custom 2-Shot Injection Molding & Double Color Plastic Parts

Technical Specifications

Key Benefits & Advantages

1. Enhanced Ergonomics & Grip: The secondary TPE/TPU layer provides a non-slip, comfortable surface, making it the industry standard for hand tool grips, button arrays, and wearable electronics.

2. Superior Aesthetic Contrast: Perfect for creating vibrant, high-contrast parts (like the black and orange components shown) with permanent color boundaries that will never peel or wear off.

3. Reduced Assembly Costs: By molding two materials in one cycle, we eliminate labor-intensive secondary assembly, adhesive application, and sonic welding, significantly lowering your total cost per part.

4. Functional Sealing: 2-shot molding is highly effective for integrated gaskets and seals, providing IP67-rated water and dust protection for electronic enclosures.

Typical Applications

Power Tools: Overmolded handles and vibration-dampening housings.

Consumer Electronics: Soft-touch remote controls, smartphone cases, and buttons.

Medical Devices: Ergonomic surgical handles and medical-grade instrument grips.

Automotive Interiors: Multi-color buttons, soft-touch knobs, and switchgear.

How the 2-Shot Process Works (Step-by-Step)

Unlike traditional overmolding, our 2-shot process is performed in a single, continuous cycle using specialized machines with two independent injection units:

Step 1 - Primary Injection: The first material (usually a rigid substrate like PC or ABS) is injected into the primary cavity to form the structural skeleton of the part.

Step 2 - Mold Rotation / Indexing: The mold automatically rotates 180° (Index Plate) or a sliding core moves to open a secondary cavity, while the first shot remains in the mold.

Step 3 - Secondary Injection: The second material (usually a soft TPE/TPU or a different colored resin) is injected over the first shot, creating a permanent, seamless bond.

Step 4 - Ejection: The finished multi-material part is ejected, and the cycle repeats instantly.

FAQ

Q1: What is the difference between 2-Shot and Overmolding?

 A: 2-shot molding occurs in a single cycle using a specialized machine with two injection units and a rotating mold. Overmolding is a two-step process where a pre-molded substrate is manually placed into a second mold. 2-shot is better for high-volume, precision parts, while overmolding is more cost-effective for lower volumes.

Q2: Will the soft rubber layer peel off over time? 

A: No. We select chemically compatible resins (e.g., ABS and TPE) that create a permanent chemical bond during the molding process, ensuring the materials will never separate.

Q3: How do I choose the right TPE/TPU hardness?

 A: Material "softness" is measured on the Shore A scale. We offer a range from Shore 30A (very soft/gel-like) to Shore 90A (hard/rubber-like). Our engineers can recommend the best hardness based on your tactile requirements.

Packaging & Delivery

• Packaging: Neutral cartons with EPE foam protection, or custom branded packaging as required, to prevent damage during transit.

• Lead Time: Mold development: 15-25 working days; Mass production: 7-15 working days (adjustable based on order quantity).

• Payment Terms: T/T, L/C, and other standard international trade terms supported.

• Logistics Options: DHL, FedEx, sea freight, air freight, and other global shipping solutions available.