Insert Molding / Overmolding

Leading of insert molding/ overmolding ... in the field of insert molding Ming-Li precision
Insert Molding / Overmolding

Application: Automotive Industry in global Automobile

Insert molding/Overmolding is one kinds of most effective molding technology which can combine metals and plastics material together into a molding part perfectly and firmly. Insert molding/Overmolding is widely used for many different applications. For example, automotive, connect, encapsulated electronic devices, threaded fasteners, medical, etc. Ming-Li company do focus on insert molding/ overmolding mold making and its injection parts mass production. Ming-Li offer one-stop insert molding/overmolding solutions, ranging from mold design to parts manufacturing. We specialize in every kinds of plastic injection molding products, not only for insert molding/overmolidng, but also for PEEK injection molding, micro injection molding, etc.
 
MING-LI is a ISO/IATF 16949 approved insert molding / overmolding company with core competence only severing consistent uncompromising quality insert molding / overmolding product to our customer. We edge over our business with investing in the state-of-the-art equipments and technology to provide the best quality of insert molding / overmolding parts. The insert molding / overmolding injection department is 100% In-House tooling which provides speed-to-market advantage. MING-LI supplies the best quality insert molding / overmolding auto parts to our valuable customers (including Automotive Tier One and Tier Two customers) all over the world. Furthermore, our insert molding / overmolding components are well-suited in coil and lamination insert molding/ Overmolding.
 
 

  • In-house CPK Rate :
    ≧ 1.33
  • Tolerance Range :
    Up to +/-0.01mm
  • Mold Size :
    600L*600W*600H ; up to 2,000kgs
  • Monthly Capacity :
    20 sets / Dies ; 25 million pcs / Overmolding & insert molding Injection parts

Material using for the insert molding / overmolding

  • Plastic Parts :
    PPS, PPA, PBT, PET, PEI, PC, POM, Nylon PA, PA6, PA66, PA9T, LCP, Derlin, Acrylic, etc.
  • Special Material :
    PEEK

Material using for the insert 

  • Metal Parts :
    Brass, Stainless steel, Aluminum, Stamping part, metal machining pins, bushing, metal coating, plating mterial, ect. 
  • Special Material :
    Ceramic, Glass, Chip, Wafer, Cable, PCB(printed circuit board), etc.                               

                                             

What is insert molding?

Insert molding mean put an insert in the mold and then process full molding process. So, you can get the part with its insert in one parts which is also a perfect combination of different material in insert molding process. The insert material usually be metal which include brass, stainless steel, stamping part, etc.

Ming-Li do have over 40 years’ experience on any kinds of insert molding molds and plastic injection parts production. Our insert molding parts are designed and manufactured for many different applications. We also have experience on IC insert molding, cable insert molding and glass insert.molding. Insert moulding is the plastic injection molding process in which a thermoplastic material is molded around an insert pieces, creating a strongly bonded, integrated assembly. We do have knowledge about metal inserts, and its coating, plating and molding expertise to reach customer request.  Any problems of insert molding process, it is very welcome to contact us for more understanding.

What is overmolding?

Overmolding is one kinds of injection molding process which make the production that is a perfect combination of different plastic material or plastice whth different component like metal, glass, rubber or silicone. Ussally, we will make the metal insert molding pre mold first and then process second injection for overmolding.
Ming-Li got the full experience on many kinds of materials for overmolding process. For example, PEEK, PPS, PEI, PBT, LCP,  PA Nylon, TPE, Silicone, etc. Ming-Li can offer customers more choices and better solution for overmolding project requirements. Our team are experts in the field of overmolding, and provide professional advice on any kinds of overmoding project at every step, from mold design, making and parts mass production.
 
 

Benefits and advantage of insert molding and overmolding

Metal inserts and bushings are commonly used for reinforcing the mechanical properties of the plastic parts or thermoplastic elastomer products that are created through the insert injection molding process. Insert molding provides a number of benefits that will improve your company’s processes all the way down to its bottom line. Some of the benefits of insert injection molding, include:

  • Improve strength & structure
  • Improve component reliability
  • Reduces the part weight and size
  • Reduces labor and assembly costs
  • Enhance design flexibility

 

Insert molding and Overmolding considerations

Our experienced staffs are expert at the insert molding and overmolding process. They have the capabilities to take insert injection materials and create plastic injection inserts from those materials. However, there are certain factors that should be considered before making a final decision regarding the insert molding process. The insert molding costs must be weighed, including the insert and tooling costs. The inserts themselves also need to be able to withstand the injection molding process, as some pressures and temperatures can damage them. Other considerations that should be factored, include:

  • Means to hold the insert during the molding process
  • Bosses or undercuts that provide additional retention strength within the molded part
  • Understanding which specific components and technologies are combined into a single component within the insert injection molding process

 

                    

Our typical insert moulded components

Many industries can benefit from incorporating insert moldings into their component design. Ming-Li precision insert moulding / overmolding cover a wide industry base including military, automotive, Inverter modules, converters, power control devices, electronics, electrical, medical, life sciences, banking equipment, aerospace, marine, furniture, building components.

The types of insert moulding / overmolding manufactured include :

 

  • Electrical and electronic pins
  • Electrical and electronic contacts and connectors
  • Inverter modules
  • Converters
  • Power control devices
  • Auto parts
  • Switches
  • Mechanical assemblies
  • Life science sensors
  • Overmolding Motor  Rotor Stator lamination stacks
  • Solenoid valve
  • Medical instruments
  • Fasteners
  • Gears

 

Insert Molding and Overmolding Mold Design Guidelines

The mold design guidelines for our basic insert moulding and overmuolding include important mold design consideration to help improve part manufacturability, increase cosmetic appearance and reduce overall production time.

Insert Molding / Overmolding is a complex endeavor, especially in light of the many variables that come into play and the possibility of reproducing mistakes in countless injection-molded copies. Ming-Li provide insert molding / overmolding services could be consulted in the early stages of part design as our expertise in the various processes can help avoid the many pitfalls that are ready and able to hamper the realization of a successful part.

In designing for insert molding / overmolding parts, a number of rules of thumb apply: overmold edges should not feather but should end abruptly and at full thickness against a stop or into an indentation. Surface texture on the overmold can significantly aid in releasing the part from the mold. It also gives the impression that the part feels softer than it actually is while disguising any flaws from the molding process. Ample draft angles help also in mold release. Mold designers need to give careful attention to gate and vent design. 

There are some unique engineering challenges that designers might face when using insert molding. The advantages of added strength and versatility must be weighed against the need for a more careful design for manufacturing review. Here are some useful guidelines to consider:

  • The single biggest concern is the shrinkage of the resin. This creates hoop stress around the fitting that can cause cracking over time, especially if the part is under mechanical tension. This is how you can counteract this:
    • Use resin material with a relatively low shrinkage rate.
    • Use resin material that has been strengthened with fillers.
    • Surround the insert with a larger area of plastic.
    • Support the insert with bosses and ribs.
    • Preheat the inserts before molding. This allows the resin and the insert to cool and shrink in tandem, thus relieving some of the stress between the materials.
  • Use pre-manufactured inserts that have knurled surfaces to help lock them in place.
  • Avoid sharp corners and use rounded profiles instead to reduce stress.
  • Design the inserts so that they’re slightly recessed. This helps to avoid damaging the tool.

 

inverter module

Our Insert Molding technology application for the next generation eco-friendly automotive

The insert molding part technology is widely using on inverter, converter and power module for EV car applications recently. Ming-Li insert molding tehnology is an injection molding process in which a thermoplastic material is molded around an insert piece or pieces, creating a strongly bonded, integrated assembly. We combine knowledge about metal inserts, plating and molding expertise to create high technique parts. Selected our insert molding technique for the inverter module controling HV motor, DCDC converter and automotive secondaly battery module.

 

Overmolding offers several advantages that make it a desirable manufacturing process in various industries:

Enhanced Product Performance: Overmolding allows for the combination of different materials with complementary properties. For example, a rigid substrate can be encapsulated with a soft, elastomeric material to improve grip, cushioning, or impact resistance. This combination of materials can enhance the overall performance and functionality of the product.

Improved Product Durability: By providing a protective layer over a substrate, overmolding can enhance the durability and longevity of a product. The overmolded material can protect the substrate from abrasion, impact, moisture, and other environmental factors, extending the product's lifespan.

Enhanced Ergonomics and Comfort: Overmolding can add ergonomic features to products, such as soft grips and contours, which improve user comfort and reduce fatigue during prolonged use. This can be particularly beneficial for handheld tools, handles, and other products where user comfort is essential.

Customized Aesthetics: Overmolding allows for the integration of different colors, textures, and finishes, enabling designers to create visually appealing and aesthetically pleasing products. This customization can enhance brand identity and market appeal.

Reduced Assembly and Labor Costs: Overmolding combines multiple manufacturing steps into a single process, reducing the need for assembly and labor-intensive operations. This can result in cost savings and increased efficiency in production.

Design Flexibility: Overmolding offers designers greater flexibility in product design, allowing for the creation of complex shapes and geometries that would be difficult or impossible to achieve with traditional manufacturing methods. This flexibility enables the development of innovative and unique products.

Improved Sealing and Waterproofing: Overmolding can create a hermetic seal around electronic components or other sensitive parts, protecting them from moisture, dust, and other contaminants. This is particularly important in applications where waterproofing and environmental sealing are required.

Noise and Vibration Damping: Overmolding can dampen vibration and reduce noise by providing a cushioning layer between moving parts or components. This is beneficial in applications where noise reduction and vibration control are important, such as automotive components and handheld devices.

Overall, overmolding offers a versatile and effective solution for enhancing product performance, durability, aesthetics, and user experience across a wide range of industries and applications.

key insert moulding

For complex insert molding part, it can make pre molding first and then process overmolding

In some cases, for complex insert molding parts, it might be beneficial to employ a multi-step process that involves pre-molding the insert before proceeding with the overmolding process. This approach can offer several advantages:

Optimized Insert Positioning: Pre-molding the insert can ensure precise positioning within the mold cavity before the overmolding process begins. This can be particularly important for complex parts with multiple inserts or intricate geometries where exact alignment is critical for functionality and performance.

Improved Adhesion and Bonding: Pre-molding the insert allows for better adhesion and bonding between the insert and the overmolded material. This can result in a stronger and more reliable bond, enhancing the overall durability and integrity of the part.

Reduced Insert Movement or Displacement: Pre-molding the insert can help prevent movement or displacement during the overmolding process, ensuring that the insert remains securely in place within the mold cavity. This is especially beneficial for inserts that are prone to shifting or rotating during injection molding.

Enhanced Control over Material Flow: Pre-molding the insert can help control the flow of molten plastic around the insert during the overmolding process. This can minimize the risk of air entrapment, voids, or defects in the overmolded material, resulting in a higher-quality finished part.

Streamlined Manufacturing Process: While pre-molding the insert adds an additional step to the manufacturing process, it can streamline overall production by optimizing the overmolding process and reducing the risk of rework or scrap due to insert misalignment or bonding issues.

However, it's essential to evaluate the specific requirements of the part and consider factors such as material compatibility, process complexity, production volume, and cost-effectiveness when determining whether to pre-mold inserts before overmolding. In some cases, a single-step overmolding process may be sufficient and more practical, especially for simpler parts or when time and cost constraints are significant considerations.

 

IGPT insert molding

Key elements for insert molding technology

Mold Design: The design of the mold is crucial for insert molding. It must accommodate the insert(s) and allow for proper flow of the molten plastic around the insert(s) to achieve the desired shape and properties of the finished part. Mold design considerations include gate location, venting, cooling channels, and part ejection mechanisms.

Insert Material Selection: Selecting the appropriate insert material is essential for achieving the desired mechanical, thermal, and chemical properties of the finished part. Common insert materials include metals (e.g., brass, steel), plastics, and ceramics, chosen based on factors such as strength, conductivity, and compatibility with the overmolding material.

Overmolding Material Selection: Choosing the right overmolding material is critical for achieving the desired performance, aesthetics, and functionality of the finished part. Factors to consider include material compatibility with the insert and substrate, mechanical properties (e.g., hardness, flexibility), thermal stability, and environmental resistance.

Insert Preparation: Proper preparation of inserts is necessary to ensure good adhesion and bonding with the overmolding material. Surface treatment techniques such as cleaning, roughening, or applying adhesion-promoting agents may be required to enhance bonding between the insert and overmolded material.

Injection Molding Process Parameters: Optimizing injection molding process parameters, such as temperature, pressure, injection speed, and cooling time, is essential for achieving uniform filling of the mold cavity, minimizing defects, and ensuring dimensional accuracy and part quality.

Mold Temperature Control: Maintaining precise control over mold temperature is crucial for achieving consistent part quality and minimizing cycle times. Proper temperature control helps prevent warping, shrinkage, and other molding defects while promoting optimal material flow and part consolidation.

Quality Control and Inspection: Implementing robust quality control measures and inspection procedures is essential for ensuring the dimensional accuracy, surface finish, and mechanical properties of insert molded parts. Inspection methods may include visual inspection, dimensional measurement, and testing for material properties and adhesion strength.

Automation and Robotics: Utilizing automation and robotics in insert molding processes can enhance productivity, repeatability, and efficiency while reducing labor costs and cycle times. Automated systems can handle insert loading, part handling, and quality inspection tasks, leading to increased throughput and consistency in production.

By addressing these key elements effectively, manufacturers can optimize insert molding technology to produce high-quality parts with complex geometries, integrated features, and enhanced performance for various applications across industries.

PEEK insert molding

Ming-Li ability for insert molding technology

Integration of Inserts: Insert molding involves the integration of pre-formed inserts, typically made of metal or another material, into the mold cavity before injecting molten plastic around them. This integration allows for combining the benefits of different materials into a single component.

Enhanced Strength and Functionality: By incorporating inserts into plastic parts, insert molding can enhance strength, rigidity, and functionality. Inserts can provide structural support, reinforcement, or specific features that improve the performance of the final part.

Reduced Assembly Steps: Insert molding reduces the need for assembly steps by combining multiple components into a single part. This streamlines the manufacturing process, reduces labor costs, and minimizes the risk of assembly errors.

Design Flexibility: Insert molding offers design flexibility, allowing for the creation of complex geometries, integrated features, and multi-material assemblies. Designers can achieve innovative solutions and optimize part performance to meet specific requirements.

Material Compatibility: Selecting compatible materials for both the insert and overmolded plastic is essential for achieving strong bonding and ensuring the integrity of the final part. Compatibility considerations include adhesion, thermal expansion coefficients, and chemical resistance.

Injection Molding Process Control: Precise control of injection molding process parameters, such as temperature, pressure, and injection speed, is crucial for achieving uniform filling of the mold cavity and minimizing defects. Proper process control ensures consistent part quality and dimensional accuracy.

Insert Preparation and Handling: Proper preparation and handling of inserts are necessary to ensure good adhesion and bonding with the overmolded plastic. Surface treatment techniques, such as cleaning, roughening, or applying adhesion promoters, may be required to enhance bonding.

Quality Assurance and Inspection: Implementing robust quality assurance measures and inspection procedures is essential for ensuring the dimensional accuracy, surface finish, and mechanical properties of insert molded parts. Inspection methods may include visual inspection, dimensional measurement, and testing for material properties.

Cost Considerations: While insert molding offers numerous benefits, including reduced assembly steps and enhanced part performance, manufacturers must consider the costs associated with tooling, materials, and labor. Cost-effective production strategies should be employed to optimize overall manufacturing expenses.

Application Diversity: Insert molding technology finds applications across various industries, including automotive, electronics, medical devices, consumer goods, and industrial equipment. It is suitable for producing a wide range of components, such as connectors, housings, handles, and sensors.

By understanding and effectively managing these key points, manufacturers can leverage insert molding technology to produce high-quality, cost-effective parts that meet the demanding requirements of modern applications.

 

The new develop for insert molding technology

Insert molding technology continues to advance, driven by the demand for more complex, integrated, and cost-effective manufacturing solutions across various industries. Here are some recent developments in insert molding technology:

  1. Advanced Materials Compatibility:

    • Development of insert molding materials compatible with a wider range of substrates, including metals, ceramics, glass, and composite materials.
    • Introduction of engineered thermoplastics with enhanced adhesion properties, allowing for reliable bonding between the insert and the molded plastic material.
  2. Multi-Material Insert Molding:

    • Advancements in multi-material insert molding techniques, enabling the simultaneous overmolding of multiple inserts with different materials in a single molding cycle.
    • Integration of dissimilar materials with varying properties, such as rigid and flexible plastics, to create complex components with tailored functionalities.
  3. Precision Molding Processes:

    • Implementation of advanced molding processes, such as micro insert molding and nano insert molding, for producing miniature components with high precision and tight tolerances.
    • Use of high-resolution molds, micro-scale tooling, and ultra-precision machining techniques to achieve intricate features and microstructures in insert-molded parts.
  4. Insert Automation and Robotics:

    • Integration of automated handling systems and robotics for precise and efficient placement of inserts into the mold cavity.
    • Use of vision systems, sensors, and feedback controls to ensure accurate positioning and alignment of inserts during the molding process, reducing cycle times and improving repeatability.
  5. Embedded Electronics and Sensors:

    • Integration of electronic components, sensors, and microchips into insert-molded parts for adding intelligence, connectivity, and functionality.
    • Development of overmolding techniques for encapsulating delicate electronic components and creating hermetically sealed enclosures for harsh environments.
  6. Surface Modification and Coatings:

    • Advancements in surface treatment technologies for improving adhesion between inserts and plastic materials, such as plasma treatment, corona discharge, and chemical etching.
    • Application of functional coatings and surface treatments to inserts for enhancing wear resistance, corrosion resistance, and surface finish of the molded parts.
  7. In-Mold Assembly and Joining:

    • Integration of in-mold assembly and joining techniques, such as ultrasonic welding, laser welding, and heat staking, for attaching inserts to molded parts during the molding process.
    • Development of hybrid molding processes combining insert molding with in-mold assembly for producing fully assembled components in a single operation.
  8. Sustainability and Recyclability:

    • Adoption of eco-friendly materials and processes for insert molding, including bio-based plastics, recycled materials, and closed-loop recycling systems.
    • Optimization of molding parameters and material formulations to minimize waste, energy consumption, and environmental impact throughout the manufacturing process.
  9. Customization and Personalization:

    • Customization of insert molding solutions to meet specific customer requirements, including design flexibility, material selection, and part geometry.
    • Integration of additive manufacturing and rapid prototyping technologies for rapid iteration and customization of insert-molded parts in product development cycles.

These developments in insert molding technology are driving innovation in industries such as automotive, electronics, medical devices, consumer goods, and aerospace, enabling the production of more complex, functional, and integrated components with improved performance and cost-efficiency. Continued research and development efforts are expected to further enhance the capabilities and applications of insert molding technology in the future.

 

Further understanding for Insert Molding / Overmolding

This is just a partial overview of insert molding and overmolding. Are they the right solutions for you? Not sure how to apply them to your next project? Just contact our technical experts and we can offer helpful advice about how to get the best results from both processes. 

 
To learn more about the insert molding / overmolding automatic production process, see our What is the insert molding? sections.

To see insert molding / overmolding process in Ming-Li please link with following YouTube video:
https://www.youtube.com/watch?v=I4eRqW78Hfo
https://www.youtube.com/watch?v=sicmD6B7Xtc

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