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Advanced Two-Color (2K) Injection Molding Services
Two-Color Injection Molding (also known as 2K or Two-Shot Molding) is the sophisticated manufacturing process of molding two different plastic materials into a single part within one machine cycle. Unlike traditional overmolding which requires two separate molds and manual handling, 2K molding utilizes a specialized press with two injection units and a rotary mold system.
At JUCHENG, we leverage this technology to produce complex multi-material components with unmatched precision and efficiency. Whether you need to bond a soft TPE grip onto a rigid ABS power tool handle, or create backlit automotive buttons with clear and opaque sections, our 2K molding service delivers a permanent chemical bond and a flash-free Class-A finish, scaling seamlessly from pilot runs to mass production.
Two-Color Injection Molding

JUCHENG’s Multi-Material Molding Capacities

We configure our 2K department to handle diverse material combinations and complex part geometries:
  • Rotary Platen Technology: Our presses feature rotary tables that spin the mold 180° between shots, allowing for simultaneous molding of the substrate and the overmold. This ensures perfect alignment and reduces cycle time.
  • Material Combinations: We specialize in Hard-Soft combinations (e.g., TPE over PP) for ergonomic grips and seals, as well as Hard-Hard combinations (e.g., Clear PC + Colored PC) for aesthetic windows and displays.
  • Core-Back Tooling: For specific geometries, we utilize core-back (sliding core) technology to expand the mold cavity for the second shot without rotating the tool, saving tooling costs.
  • Chemical Bonding: Our engineers select compatible material pairs to ensure a molecular bond, eliminating the need for mechanical interlocks or adhesives.
2K injection molding machine

Product Gallery Categories

Soft-Touch Grips (Hard + Soft)
Soft Grips
Integrated Seals & Gaskets
Integrated Seals
Multi-Color Aesthetics
Multi-Color
Backlit Buttons (Day/Night Design)
Backlit Buttons
Vibration Dampeners
Medical 2K

Materials Available

2K Material Compatibility
Successful 2K molding relies on the chemical compatibility (adhesion) between the two materials. We guide you in selecting the right pairs:
Substrate (1st Shot) Overmold (2nd Shot) Application Example
PP (Polypropylene) TPE (Thermoplastic Elastomer) Toothbrushes, food containers, disposable razors.
ABS / PC-ABS TPU (Thermoplastic Polyurethane) Power tool handles, rugged phone cases, industrial grips.
PC (Polycarbonate) TPU / TPE Waterproof electronics, wearable devices.
PC (Clear) PC (Black/Colored) Automotive lenses, display windows with bezels.
Nylon (PA) Modified TPE Specialized automotive components (Chemical bonding is difficult, often requires mechanical locks)

Comparison

Comparison: 2K Molding vs. Insert Overmolding
Which multi-material process fits your project?
Feature Two-Shot (2K) Molding Insert Overmolding
Process One machine, one cycle, automated transfer. Two machines (or two molds), manual/robot transfer.
Cycle Time Fast (Parallel processing). Slow (Handling time required).
Tooling Cost High (Complex rotary mold). Medium (Two simpler molds).
Part Quality Superior (Perfect alignment, no flash). Good (Risk of placement error).
Ideal Volume High Volume (>10k). Low to Medium Volume.
Bonding Optimal (Substrate is still hot). Good (Substrate is cold).

Why Choose Us

The JUCHENG 2K Advantage
  • Tooling Expertise: Designing 2K molds is exponentially more difficult than standard molds. Our in-house engineering team uses Moldflow simulation to balance the filling of both shots and prevent "shoot-through" or warping.
  • Cost Efficiency: For high-volume production, our automated 2K process eliminates assembly labor and reduces defective rates, offering the lowest total cost per part.
  • Visual Perfection: We ensure clean shut-offs between colors/materials, delivering a premium look without bleed or flash.
  • Turnkey Solution: From material selection to mold building and mass production, we manage the entire complexity of multi-material manufacturing.

Advantages

Benefits of Two-Shot Technology
  • Eliminate Assembly: Combines multiple functions (structure + seal + grip) into one part, removing the need for gluing or screwing.
  • Enhanced Quality: Chemical bonding creates a seamless, watertight interface that is stronger than mechanical assembly.
  • Aesthetics: Allows for complex multi-color designs and soft-touch surfaces that increase the perceived value of the product.
  • Ergonomics: Adds non-slip, comfortable surfaces to handheld devices.

Industries Served

Industries Using 2K Components
  • Automotive: Interior buttons, AC vents, steering wheel controls, integrated seals.
  • Consumer Goods: Toothbrushes, razors, baby products, kitchen utensil handles.
  • Electronics: Waterproof smartphone cases, wearable bands, ruggedized tablet housings.
  • Medical: Syringe plungers, soft-touch surgical instruments, respiratory masks.
  • Power Tools: Drills, saws, and sanders featuring the iconic "soft grip" design.
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    Factory Address :
    Shenzhen: Fourth Industrial Zone, Xisha Road, Shajing Street, Baoan District, Shenzhen.
    Dongguan: Building 5 and 4, No. 198, Chang'an Section, Guanchang Road, Chang'an Town, Dongguan.
     
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    unit 1, Enterprise City,Durham DL16 6JF, united Kindom
     
     
    +86 - 186 - 8005 - 3076

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