Two-Shot Injection Molding

Quick comparison

	Regular Over-molding	2K Injection Molding
Tooling Quantity	2 sets	1 set
Tooling Cost	Low	High
Tooling Lead Time	Fast (generally in 20-30 days)	Slow (generally 35-45 days)
Production Quantity	50-100,000pcs	10,000pcs or more
Mini. Batch Quantity	No MOQ	5000 pcs/batch
Production Cycle Time	Long and low efficient	Short and efficient
Unit Price	Medium-high	Low

‌Distinguishing Between Double Injection Molding and Regular Overmolding

‌A. 2K Injection Molding:
This refers to a mold where two plastic materials are injected on the same injection molding machine, undergoing two separate molding processes but resulting in a single product ejection.
Commonly, this molding technique is also known as dual-material injection molding, and it is typically accomplished using a single set of molds. A specialized 2K injection molding machine is required for this process. ‌

B. Regular Overmolding Molding (Two-Stage Molding)‌:
This mold involves two plastic materials that may not necessarily be injected on the same injection molding machine. The process is divided into two stages; after the product is ejected from one set of molds, it is placed into another set of molds for the second injection molding stage.
Therefore, this molding technique generally requires two sets of molds and does not necessitate a specialized two-color injection molding machine.

2K/Double Injection Molding

Double Injection Molding, also known as 2K injection molding. 2K injection molding is a versatile process extensively employed for overmolding two components or achieving a dual-color effect.
This technique not only yields premium products with a soft-touch feel or vibrant dual-color appearance but also ensures cost-effectiveness through automated production. In our daily lives, we encounter numerous consumer products that utilize this process, such as brush handles and tool case handles, serving as testament to its widespread application.
JY Pretech typically uses the following thermoplastic materials for 2 component molding(2K molding / 2K injection) :
1. Styrene Block Copolymers (TPE-S)
2. Thermoplastic Polyurethane Block Copolymers (TPE-U)
3. Copolyesters (TPE-E)
4. Copolyamides (TPE-A)
5. Olefinic Thermoplastic rubbers (TPE-O)
JY Pretech typically uses the following plastic materials for 2 Shot moulding(2K molding / 2K injection) :
1. Polyamide (PA/Nylon)
2. Polybutylene Terephtalate (PBT)
3. Polycarbonates (PC)
4. Polypropylene (PP)
The two-shot molding process enables us to design and manufacture complex, multi-material parts that perform sealing functions for our customers.
Additionally, the multi-shot molding process can be used as a cost-effective method to bond materials in different colors for cosmetic purposes.

2K Injection Molding Design Guide

Remember that 2K molding is rarely used to cover the entire base substrate. Instead, apply 2K molding in sections.

For each of these, keep the following useful design tips in mind:
- Work with your manufacturing partner to ensure compatibility between the substrate and the TPE or TPU.
- Use a TPE or TPU with a melt temperature lower than that of the base plastic.
- Apply an overmold that is slightly thinner than the substrate it supports.
- Design the overmold to sit just below the surface of the substrate.
- If you need more holding power, incorporate undercuts, keyways, or other mechanical features to lock the materials together.

2K injection molding, double injection molding, and precision manufacturing expertise by JY Pretech.

The Capacity of 2K Injection Molding at JY Pretech:

1. 400T MULTIPLAS Double Injection Molding Machine X1
2. 268T Chen Hsong Double Injection Machine X1
3. 250T HAITIAN Double Injection Machin X3

Disadvantage

When utilizing 2K injection molding, certain challenges arise in tooling for injection molding:
1. For large-scale production, the 2K injection molding tool must exhibit high precision to ensure smooth tooling movements, including opening/closing and 180-degree rotation.
2. Additionally, the tooling must possess reliable strength and a stable lifespan to facilitate high-efficiency and consistent injection molding production.
3. Consequently, the cost of injection molding tooling tends to be high, and the lead time for tooling fabrication can be lengthy.

However, by partnering with a dependable injection molding manufacturer and implementing appropriate project management for scheduling, it becomes evident that 2K injection molding offers substantial advantages for high-volume injection molding applications.

Advantage

‌Advantages of the Production Process‌:
1. ‌Cost Reduction‌:
    a. ‌Super low part price‌: Produced by 2-component molding without post-processing. ‌
     b. Engineering cost savings‌: Efficient process design. ‌
    c. Lower management effort‌: Streamlined injection molding operations. ‌
2. Product Quality and Efficiency‌: ‌
    a. Cosmetic & tidy parts‌: High precision tooling eliminates post-trimming/cleaning. ‌
    b. Time and cost savings‌: Reduced assembly/secondary operations. ‌
    c. Stable production schedule‌: Predictable and reliable manufacturing timeline. ‌
3. Market Enhancement‌ ‌
    a. Increased product value‌: Enhanced quality and appearance.
    b. ‌Improved marketability‌: Attractive and competitive products.

This process offers significant benefits in cost efficiency, product quality, and market appeal.

Enhanced Design and Aesthetics

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Capabilities: High Heat Material Processing; Two-Shot Injection Molding; LSR-Liquid Silicone Injection Molding; Metal 3D Printing + Post Machining; Export Tooling + Mold Components; Sheet Metal Forming; Compression Molding; Rapid Prototype Injection Tooling and Molding

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Contact Us

info@jypretech.com

+86 137 2602 0720

WeChat & Address: JY Pretech Co., Limited

No.5 Factory, Daliao Road,
East District, Zhongshan City, Guangdong Province, China, 528437

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