Two-color overmolding injection mold

Core Product: Custom Two-Color Overmolding Injection Molds

We specialize in the customized design and manufacturing of high-precision two-color overmolding injection molds, which are core production equipment for realizing integral forming of multi-material components by combining two different plastics (e.g., hard plastic + soft plastic, different color plastics). Our core function is to provide durable, high-precision two-color molds that ensure tight bonding between two materials, consistent dimensional accuracy, and excellent surface finish of the molded products—critical for components requiring both structural rigidity and tactile comfort, or color differentiation. Backed by a professional technical team of 35+ engineers and technicians, we leverage advanced CAD/CAM/CAE software (UG, AutoCAD, SolidWorks) to conduct in-depth simulation of the two-color overmolding process, optimizing mold cavity structure, gate design, and rotational positioning mechanism to avoid defects such as material delamination, color mixing, and poor bonding. Our molds are tailored to match the compatibility of different plastic materials (e.g., ABS+TPR, PC+Silicone, PP+TPE) and mass production needs, featuring stable rotational positioning, short molding cycles, and long service lives.

Production Process & Supporting Technologies

The production of our two-color overmolding injection molds follows a strict standardized workflow that focuses on precision and material compatibility: 1. Demand Analysis & Design (confirm client’s component specifications, two-material combination requirements, and production capacity; conduct 3D mold modeling and two-color overmolding process simulation to verify material flow and bonding feasibility); 2. Raw Material Preparation (select high-quality mold steel (S136, H13, P20) with excellent wear resistance and thermal stability; implement precision cutting via CNC flame cutting equipment); 3. Precision Machining (carry out CNC milling, grinding, EDM, wire cutting, and high-speed machining to ensure the machining accuracy of mold cores, cavities, and rotational mechanisms, with key positioning dimensions controlled within ±0.005mm); 4. Assembly & Debugging (skilled technicians perform manual assembly, install precision rotational positioning components, and conduct multiple rounds of debugging and trial injection on two-color injection molding machines to optimize molding parameters and ensure stable material bonding); 5. Quality Inspection & Delivery (use coordinate measuring machines (CMM) and tensile testing equipment to inspect mold dimensions and material bonding strength; conduct trial injection tests to verify product appearance and performance, and provide test reports). In addition to specialized two-color overmolding injection molds, we also provide supporting processes such as surface treatment (painting, laser engraving), finished product assembly, and packaging, achieving full-chain service for clients.

Common Problems & Solutions in Two-Color Overmolding Injection Mold Production

• Problem 1: Poor bonding between two materials (delamination) - Solution: Conduct material compatibility testing in advance to select matching material combinations; optimize the mold design to increase the bonding area between two materials (e.g., add grooves or serrations); adjust injection parameters (injection temperature, pressure, and holding time) to enhance material fusion; pre-heat the first-color component before the second injection to improve bonding strength.

• Problem 2: Color mixing or contamination between two materials - Solution: Optimize the mold runner and gate design to separate the two material flows; use dedicated nozzles and barrels for each material on the two-color injection molding machine; clean the mold and injection system thoroughly before production; select materials with good thermal stability to avoid material degradation and color migration.

• Problem 3: Positioning deviation of the two-color components - Solution: Enhance the precision of the mold’s rotational positioning mechanism (e.g., use high-precision linear guides and servo motors); optimize the mold’s guiding structure to ensure stable movement during rotation; strictly control the machining accuracy of mold components to reduce assembly errors; adjust the injection pressure and speed to avoid component deformation during molding.

Frequently Asked Questions (FAQ)

• Q1: What types of two-color overmolding components can your molds produce? - A1: Our molds can produce various two-color overmolding components, including automotive interior buttons (hard plastic + soft rubber), electronic device casings (different color plastics), medical device handles (rigid plastic + soft grip), and household appliance knobs (ABS+TPR). We support customization based on client-specific drawings and material combination requirements.

• Q2: What is the lead time for custom two-color overmolding injection molds? - A2: The lead time varies by mold complexity: sample molds take 10-20 working days, mass production molds take 25-50 working days, and urgent orders can be completed in 7-15 working days with an additional fee. The longer lead time compared to single-color molds is due to the complex rotational structure design and precision debugging requirements. We will provide a detailed production schedule after confirming the order.

• Q3: Do you provide quality assurance for your two-color overmolding injection molds? - A3: Yes, we provide a 12-month quality guarantee for all injection molds. During the guarantee period, if there are quality problems caused by mold design or manufacturing (e.g., material bonding failure, positioning deviation), we will provide free repair or replacement services. We also offer lifelong technical support for mold maintenance and parameter optimization.

• Q4: Can you provide two-color overmolding production services for finished components? - A4: Yes, we are equipped with 15+ high-precision two-color injection molding machines (80-500 tons) that can meet the production needs of different sizes of two-color components. We can provide one-stop services from mold design, fabrication to finished product two-color overmolding and assembly, which can effectively reduce your communication costs and shorten the production cycle.

• Q5: What certifications do your two-color molds and finished products have? - A5: Our factory is certified by IATF16949 (automotive industry quality management system) and ISO9001:2015. The plastic materials we use comply with RoHS, REACH, and food grade (FDA) certifications (if applicable). We can provide relevant certification documents and material bonding strength test reports according to client requirements.

Product Classification & Technical Specifications

1. Product Classification by Industry, Material & Part Type

2. Technical Specification Parameters

Our Core Competitiveness

• 10+ Years of Two-Color Overmolding Expertise: Founded in 2012, we have focused on two-color overmolding injection mold manufacturing, serving more than 200 clients from over 40 countries, including leading manufacturers in the automotive, electronics, and medical industries. Our rich experience enables us to accurately grasp the technical difficulties of two-color overmolding and provide targeted solutions.

• Professional Technical Team: A team of 100+ engineers and technicians with an average of 8+ years of industry experience, proficient in the design and optimization of two-color overmolding injection molds. They are skilled in handling technical difficulties such as material compatibility matching, precision rotational positioning, and bonding strength optimization.

• Strong Production Capacity: Our factory covers an area of 12,000 square meters, equipped with 100+ sets of advanced production and testing equipment (CNC milling machines, EDM machines, wire cutting machines, CMM, high-precision two-color injection molding machines, tensile testing machines, etc.), with an annual production capacity of 200+ sets of injection molds and 8 million+ finished two-color components.

• Strict Quality Management System: Certified by IATF16949 and ISO9001:2015, we implement full-process quality control from raw material incoming inspection to finished product delivery. We have established a professional quality inspection team and equipped with complete testing equipment to conduct strict inspections on mold precision, material bonding strength, and product appearance, ensuring compliance with international standards.

• Improved Supply Chain: Cooperate with reliable domestic raw material suppliers to ensure stable supply and consistent quality of mold steel and plastic materials (including special two-color combinations); integrate upstream and downstream resources to realize cost optimization and timely delivery.

• Global Service Capabilities: Cooperate with well-known international logistics companies (Maersk, COSCO) to provide efficient and safe global shipping services, leveraging the geographical advantage of Qingdao Port to shorten delivery time. We offer 24-hour online technical support and a 12-month quality guarantee to solve after-sales problems promptly for clients around the world.

Customer Case: Two-Color Overmolding Injection Mold Project for North American Automotive Client

Our client is a leading automotive interior parts manufacturer in the United States, specializing in the production of high-end automotive interior components. They encountered problems with their original two-color overmolding molds for automotive interior buttons (ABS+TPR), including poor bonding between ABS and TPR (delamination rate exceeding 8%) and serious positioning deviation (±0.05mm) which led to uneven soft rubber edges, affecting product aesthetics and performance. In 2023, they partnered with us to customize a set of high-precision two-color overmolding injection molds for their new model’s interior buttons.

Our technical team first conducted a detailed analysis of the client’s interior button drawings and performance requirements (bonding strength, positioning accuracy, tactile feel). We conducted material compatibility testing on ABS and TPR to confirm the optimal matching ratio, then used UG software to build a 3D model of the two-color overmolding mold and simulated the injection process. We optimized the mold’s rotational positioning mechanism by adopting high-precision servo motors and linear guides to ensure positioning accuracy within ±0.01mm; we also designed a special groove structure on the ABS substrate to increase the bonding area with TPR. During the debugging stage, we adjusted the injection parameters (temperature, pressure, and holding time) for both materials and conducted multiple rounds of bonding strength tests to optimize the molding process.

The final delivered injection molds achieved excellent results: the delamination rate of the automotive interior buttons was reduced to less than 0.3%, the positioning accuracy of the two colors was controlled within ±0.01mm, and the soft rubber edges were smooth and uniform. The buttons also met the client’s strict requirements for tactile feel and wear resistance. The client highly recognized our product quality and technical service, and signed a long-term cooperation agreement with us, covering multiple models of automotive two-color interior components.

Why Choose Qingdao Xinlongji?

1. Professional Customization for Two-Color Overmolding: We focus on the R&D and manufacturing of two-color overmolding injection molds, with in-depth understanding of material compatibility and precision positioning technology, ensuring that we can provide high-quality solutions for complex two-color components.

2. One-Stop Integrated Service: From mold design, fabrication to finished product two-color overmolding and assembly, we provide a full range of services, helping you simplify the supply chain and reduce communication and management costs.

3. Proven Technical Strength: Our professional technical team and advanced simulation technology can effectively solve various complex problems in two-color overmolding, ensuring product quality and production efficiency.

4. Reliable Quality Assurance: International quality system certification and full-process quality control ensure that our products comply with global industry standards, minimizing your production risks and helping you enter the international market smoothly.

5. Efficient Global Support: We have rich experience in international trade and perfect global logistics channels, ensuring timely delivery of products to your designated location. Our 24-hour technical support team provides professional after-sales services to solve your worries during the production process.

Qingdao Xinlongji Metal Manufacturing Co., Ltd. is committed to becoming a trusted partner in the global two-color overmolding injection mold industry. We look forward to cooperating with you to create greater value! For more information about our products and services, please feel free to contact us.