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Overmolding Services

Service Title: Innovative Overmolding Solutions

Service Overview: Our Overmolding services provide a versatile and cost-effective way to combine two or more materials into a single, cohesive part. This process is particularly useful for integrating different materials with dissimilar properties, allowing for a wide range of applications in various industries. We specialize in overmolding thermoplastic materials onto metal, plastic, or other thermoplastic parts, creating a strong bond that maintains the characteristics of both materials. Our advanced equipment and experienced team ensure that every overmolded part meets the highest quality standards.

About Us

At ShenZhen GuoChangHong Precision Metal Co.,Ltd, we are dedicated to delivering innovative overmolding solutions to a diverse range of industries. With years of experience and a commitment to excellence, we provide customized overmolding services that meet our clients' exact specifications. Our continuous investment in overmolding technology and our commitment to quality assurance sets us apart as a trusted partner for all your overmolding needs.

Overmolded Parts Services
Our Overmolded Parts services provide a comprehensive range of capabilities to produce high-quality, integrated parts. We specialize in overmolding thermoplastic materials onto metal, plastic, or
Overmolding Services
Our Overmolding Services are designed to provide a versatile and cost-effective way to combine two or more materials into a single, cohesive part. This process is particularly useful for integrating
Plastic Overmolding Services
Our Plastic Overmolding services are designed to produce high-quality plastic parts with added functionality and durability. We specialize in overmolding thermoplastic materials onto other plastic or
Silicone Overmolding
Our Silicone Overmolding services provide a versatile and cost-effective way to combine silicone with other materials into a single, cohesive part. This process is particularly useful for integrating

Reasons to Choose Our Overmolding Services

Versatility Title:

Custom Overmolding for Diverse Applications Our overmolding services are fully customizable, allowing you to choose the color, texture, and other properties of the overmolded material to match your design and functional needs.

Durability Title:

Enhanced Durability and Bond Strength Our overmolding process creates a strong bond between the core and overmolded materials, ensuring the longevity and performance of your parts.

Quality Assurance Title:

Strict Quality Control for Consistent Results We maintain rigorous quality control processes throughout the overmolding process. Our ISO-certified facility and experienced quality inspectors ensure that every part meets the highest standards of quality and performance.

Environmental Responsibility Title:

Eco-Friendly Overmolding Solutions We are committed to environmental sustainability. Our overmolding processes are designed to minimize waste, reduce energy consumption, and comply with the latest environmental regulations, making us a responsible choice for your finishing needs.

What Is Overmolding

An existing molded object can have a second layer of resin added to it using the tpu injection moulding technique known as overmolding to provide a combination of properties that no one material can. One of the most popular uses is to place a TPE (thermoplastic elastomer) layer of soft, useful, and hand-friendly rubber-like material over a hard substrate.

Advantages of Overmolding

Increased Material Flexibility
Overmolding necessitates the assemblage of several components. Utilizing all of the advantages of the materials used increases the part's flexibility. producers can increase flexibility by using the overmolding design guide.

Elimination of Adhesives
Overloading does not require adhesives since overmolding allows diverse parts to fuse together naturally. As a result, the products' durability improves. The cost of production has decreased overall as well.

Better Product Performance
Including additional high-quality materials improves a product's performance greatly. Overmolded items have two material advantages over standard products utilized in industries. Because of this, overmolded items perform better.

Custom Plastic Parts
Overmolding has the benefit of enabling the design and production of unique plastic components for virtually any business. Overmolded items with high dimensional quality can be produced by manufacturers using a plastic-plastic or metal-plastic combination.

Reduced Manufacturing Cost
Overmolding is completed in one cycle of operation. As a result of the lack of two- or multi-part assembly, the procedure is accelerated. They can lower their manufacturing costs and accelerate the entire process because overmolding eliminates the post-assembly stage.

Why Choose Us

01/

Rich Experience
Our company has many years of production work experience. The concept of customer-oriented and win-win cooperation makes the company more mature and stronger.

02/

Competitive Price
We have professional sourcing team and cost accounting team, stive to reduce cost and profit and provide you a good price.

03/

Sustainable Development
Establish a good reputation and brand value in the industry, and promote the sustainable, stable, rapid and healthy development of the enterprise.

04/

Advanced Equipment
A machine, tool or instrument designed with advanced technology and functionality to perform highly specific tasks with greater precision, efficiency and reliability.

05/

One Stop Solution
From the begining inquiry and throughout the entire process until you receive the goods. we are dedicated to supporting you every step of the way.

06/

Quality Products
We use only the highest-grade materials and advanced manufacturing techniques to produce products that are reliable, durable, and perform to the highest standards.

How Does Overmolding Work

A machine part or component made by fusing two or more materials together is the end product of the overmolding process. Either the same materials or alternative materials can be used. There are essentially no limits to the material combinations.

We must comprehend the two elements of the process in order to have a better understanding of how it functions. Each overmolding job is divided into two components. The substrate is the first step in the process, while the overmold is the second.

The substrate serves as your starting point. Any of a huge range of materials could be used. Your overmold is the auxiliary substance. You want to “mold over” the substrate with this substance.

There may be two or more overmolds present in some circumstances. The amount of overmolds is entirely dependent on the final product that is sought and the manufacturer's creativity.

Comparing Insert Molding To Overmolding

Overmolding and insert molding enable manufacturers to create multi-material products without using adhesives, help eliminate secondary assembly steps, and improve the final product. It's important to note the differences between insert molding and overmolding, including:

Process
Overmolding involves injecting two shots of materials to form the substrate and the overmold. Insert molding only involves injecting one shot of molten plastic, though the metal insert needs to be purchased or created separately.

Speed
Insert molding involves one shot while overmolding involves multiple, which means the insert molding cycle time is generally faster than the overmolding cycle time. that doesn't necessarily mean that insert molding is always the fastest option for production. manufacturers may be unable to find pre-made metal inserts that meet their requirements, meaning they'll need to create a custom metal insert, which can lengthen production timelines.

Cost
Insert molding and overmolding can reduce assembly costs and accelerate production, helping companies simultaneously save on production costs and generate greater profits when producing large quantities of parts. overmolding is more expensive than insert molding, as it involves two steps. This is particularly true when it comes to prototype or small production runs, as overmolding requires manufacturing two tools - one for the substrate and one for the overmold.

Applications
Overmolding is often used to make toothbrushes, medical instruments, disposable razors, and phone cases, or to enclose electronic circuit boards (e.g. USB flash drives).

Overmolding Materials

When it comes to selecting overmolding materials, smart manufacturers rely on a general evaluation process for all types of materials. New materials are constantly being developed. It helps to have a standard evaluation process to compare them to rather than trying to evaluate each material individually.

Here Is What You Should Look For In Any Overmolding Material You Evaluate.

Temperature
Certain materials are great for flexible applications, but they don't stand up to extreme temperatures. Most of the overmolding methods used involve some form of heat. This is especially true when it comes to injection molding.

You'll want to make sure you select materials that can stand up to high temperatures without losing any of their original features. This applies to both your overmold material, as well as your substrate material.

Hardness
The overmolding process can be tough on the materials involved. Occasionally, you'll need a material that's firm enough to stand up to indentation during the overmolding process.

You'll also need to evaluate whether or not the material you're using will bend. This is important because if the material bends, it may affect the grip of your end product. If the grip of the end product is compromised, the two materials may not hold together.

Thickness
Material thickness is another great indicator of performance. Sometimes the overmolding process is used in sound or vibration dampening applications. These types of applications require thick materials to make sure the end product is doing its job.

Thicker material will absorb vibration well. It will also feel soft. Thinner materials will feel more rigid and they won't perform as well when it comes to dampening vibration or sound.

Bonding
The goal of any overmolding process is to get the materials you're using to bond together. Some materials may have difficulty bonding to one another.

You may be able to “force” two materials to come together that are struggling to bond. This can be done by making indents or undercuts in one of the materials to help the process along.

Friction
The friction level of each material used in the overmolding process can vary. Friction determines how easily two materials can move against each other. Each material has its own “coefficient of friction” which dictates how much or how little friction it creates.

A material's coefficient of friction, as well as its surface texture, are very important components of successfully bonding materials together. The more friction and surface texture there is, the easier it will be for two materials to bond to one another.

The Process Of Overmolding

Design And Preparation

The first step in the overmolding process is to design the surface texture of the part and determine the same mold materials to be used. The substrate and over mold base component materials must be compatible and able to bond together. Once the design is finalized, the substrate is prepared for the molding process by cleaning and pre-treating the surface.

Injection Molding

The substrate is then placed in a co-injection molding cavity, and the overmold material is injected into the cavity around the substrate. The injection molding process works and is then cooled to allow the two materials together to bond together.

De-Molding And Finishing

Once the part has cooled and solidified two-shot molding, the injection molding machines, are opened, and the part is removed molding machine. The part is then finished and any excess material is removed through trimming or machining.

Quality Control

The finished part is inspected to ensure it meets both the used substrate material, and required specifications and quality standards.

Four Types Of Overmolding

There are four common over-molding types available.

Plastic Over Plastic

The substrate and the plastic poured over the substrate are both plastics. The material of the plastic components should have the same or similar melting point.

Plastic Over Metal

The substrate is metal. A metal part, CNC-machined, cast, or forged, is put into the mold first, and then the plastic is molded over the metal part.

Elastomer Over Plastic

The substrate should be hard plastic. Elastomers could be soft materials such as rubber and polyurethane.

Elastomer Over Metal

The substrate is metal. A metal part, CNC-machined, cast or forged, is put into the mold first, and then the elastomer is molded over the handle.

Application of Overmolding

The overmolding process can be applied to a myriad of industries and has diversified applications. Some of these applications are listed below:

Medical Industry
Medical overmolding is one of the most specialized applications of overmolding. Many medical devices are required to have a rigid substrate with a soft overmold. By utilizing medial overmolding, VEM can produce a range of medical devices, and high performance equipment that has a non-slip design.

When it comes to medical device manufacturing, we ensure to conform to the stringent requirements of the medical manufacturing industry to manufacture the highest quality product.

Automotive Industry
The overmolding process is also a very popular injection molding technique in the automotive industry. It is often a preferred technique to produce handles, components of car seats and headrest, car handles, energy absorber mounts, car hood, and dashboard accessories.

Prior to overmolding, these components were manufactured either solely or largely with metal to maintain durability. Post over-molding, these components can be manufactured to be not only durable but also light-weight and desirable for the consumer.

When molding automotive products and parts, it is imperative to take into account the numerous factors that are related to vehicle movement. Today, molding automotive products and parts requires material behavior and manufacturing processes to be considered at an early design stage. This helps us to streamline any obstacles that may arise in manufacturing.

Electronics Industry
Another industry where overmolding techniques are very extensively used is the electronics industry. Many parts are over-molded in the electronics industry to seal the sensitive electronics components and connect it with the cables.

The most significant overmolding applications in the electronics industry are PCB, thermostat and circuit board overmolding. In this type of overmolding, electronic assemblies are positioned within a mold. Once they are positioned, they are then injected upon with molten plastic which then hardens into a protective layer. This ultimately reduces the damage risk by sealing the junction between the wires and connectors. Almost every electronical product that you can see has some degree of overmolding involved in their production.

Overmolding Operations

The overmolding process is the same as an injection molding process, except that the plastic is molded over another component. The difference lies in operation. With overmolding, the substrate is loaded into the mold on each cycle. how the substrate is loaded creates two different overmolding operations:

Manual Molding

With a manual operation, the substrate is injection molded via a traditional injection molding process. The substrates are then hand-loaded into another mold for the overmolding operation. The operator will also remove the finished part from the mold, provide an inspection, and package the parts. Manual overmolding is the most common procedure for low to mid-volume overmolding.

The advantage of manual overmolding is simplicity. The tooling required for the substrate and overmold is simple (when compared to two-shot tooling), and there is no secondary equipment required. As annual order volumes increase, the labor involved can become significant enough to justify investment in automation systems or a two-shot molding operation.

Two-Shot Molding

More advanced injection molding machines can run two different polymers at the same time. Two-shot molding uses a complicated mold and robotics to mold the substrate on one side and then transfer it to the other half. This happens on every cycle. The process requires a more advanced injection molding machine and mold, but it may yield a lower piece price compared to manual operations.

Deciding between the two molding operations is done on a case by case basis. There is no universal rule as to when an automated overmolding operation is justified. To provide the end-user with the best option, injection molders will look at several variables, such as: labor allocation, annual order quantities, budget, material usage, cycle time, etc.

Design Considerations For Overmolding
Given the complex nature of overmolded parts, there are several considerations during design for manufacturing. If the part experiences large amounts of mechanical stresses, part retention features are required to prevent the two materials from separating.

Another way to prevent separation is to use both mechanical and chemical bonding methods when creating the overmolded part. Tool design must account for any shift to the substrate caused by the injection molding process. If the substrate were to shift inside the tool, this could cause significant damage.
Overmolding can reduce part costs by combining materials into one part. It is just one method of plastic injection molding that has extensive experience in developing. If you are unsure if overmolding would be the correct process for your project or would like some expert manufacturing advice, contact us and we would be happy to help.

Certifications

Our Factory

Shenzhen Guochanghong Precision Hardware Co., Ltd. We are a high-precision manufacturing company integrating mold design, manufacturing, assembly, sales and service. Our equipment is complete, and products can be completed in one stop from raw materials to finished products. We have a full set of precision equipment, including 4 precision aluminum alloy die-casting machines, 42 CNC lathes, 70 CNC machining centers, 35 drilling and tapping machines, 2 gear machines, 5 milling machines, and 6 medium-speed wire cutting machines.

FAQ

Q: What is overmolding and how does it work?

A: Overmolding is a manufacturing process that involves placing a core part (usually made of metal, plastic, or another thermoplastic) into a mold and then injecting a second material (usually a thermoplastic) over it. This creates a single, cohesive part with two or more materials.

Q: What are the benefits of overmolding?

A: Overmolding offers several benefits, including the ability to integrate different materials with dissimilar properties, create a strong bond between the core and overmolded materials, and maintain the characteristics of both materials. It is a versatile process that can be used in various industries.

Q: What types of materials can be overmolded?

A: Our overmolding services can be applied to a variety of materials, including thermoplastics, metals, and some types of elastomers. We can handle different thicknesses and types of materials to meet your specific requirements.

Q: How do I get started with your overmolding services?

A: To get started with our overmolding services, simply provide us with your design files and material specifications. Our team will assist you in every step of the process, from material selection to the final delivery of your overmolded parts.

Q: What is the purpose of overmolding?

A: Overmolding reduces the need for product assembly because parts are manufactured right on top of one another - resulting in a stronger, more durable overall design.

Q: What are the design considerations for overmolding?

A: Proper draft angles, uniform wall thickness, and smooth transition lines must be maintained in both parts. The thickness of the overmold material should be less than or equal to that of the substrate below it.

Q: What is the tolerance of overmolding?

A: With thermoplastic overmolds, tolerances remain the same as substrate molds, however, if the overmold is LSR, then tolerances shift to 0.025 in./in. (0.025mm).

Q: What is the difference between two-shot molding and overmolding?

A: Two-shot molding usually only makes sense for larger production runs, whereas overmolding is better for low volume production runs.

Q: What is the injection overmolding technique?

A: Injection or overmolding techniques in composites involve the process of injecting or molding a composite material over a pre-existing structure or component, enhancing its functionalities or adding protective layers.

Q: What is the process of rubber overmolding?

A: Also called metal insert molding, rubber overmolding is a process by which rubber is bonded and molded over a metal substrate. Overmolding rubber to metal involves a mechanical or chemical bonding technique or a combination of both techniques. The finished parts offer enhanced rigidity and a range of other benefits.

Q: What is the best material for overmolding?

A: The most commonly used plastic grades for substrates include PC/ABS, ABS, Nylon and PBT. TPE, TPU or silicone rubber are most suitable for overmolding.

Q: What material is used for overmolding?

A: It has reasonable chemical compatibility with most of the soft, thermoplastic elastomeric materials that are used for grip and seal applications in these products. ABS is generally the substrate material in pairing with a soft material used for the overmolding.

Q: What is an example of overmolding?

A: Overmolding is commonly used to manufacture plastic parts that feature a rubber handle. The two-shot process of overmolding a toothbrush, for example, consists of forming a base layer for the plastic handle and a top layer of rubber (to make the toothbrush less slippery to hold).

Q: How is overmolding done?

A: With a manual operation, the substrate is injection molded via a traditional injection molding process. The substrates are then hand-loaded into another mold for the overmolding operation. The operator will also remove the finished part from the mold, provide an inspection, and package the parts.

Q: What Is Overmolding?

A: Unlike the typical injection molding workflow, overmolding is a manufacturing process that requires more than one molding cycle to produce the finished part. In this manufacturing effort, the goal is to create a product that fully exhibits the properties of the different plastic materials chosen in addition to different colors between parts. For example, a product might have a rigid plastic interior for strength and rigidity, which then undergoes overmolding to produce a surface that is easier for a hand to grip.

Q: What is the difference between substrate and overmold?

A: Overmolding involves injecting the plastic into a mold to form the first plastic part (also known as the substrate). on solidification, the substrate is placed in another mold and injected with the second plastic material (overmold). the substrate becomes encapsulated with the overmold.

Q: Is injection molding the same as roto molding?

A: Injection molding uses plastic pellets that are melted and then injected into a mold, or tool, via hydraulic pressure. Rotational molding loads powder or resin into a mold which rotates on two axes inside an oven until the inside of the mold is coated uniformly.

Q: What is the difference between substrate and overmold?

A: Overmolding involves injecting the plastic into a mold to form the first plastic part (also known as the substrate). Then, on solidification, the substrate is placed in another mold and injected with the second plastic material (overmold). the substrate becomes encapsulated with the overmold.

Q: What is the thickness of overmolding?

A: Wall thickness in the range from 0.060" to 0.120" will ensure good bonding in most overmolding applications. If the part requires the use of thick sections, they should be cored out to minimize shrinkage problems and to reduce the part weight.

Q: What is the difference between overmolding and insert molding?

A: Overmolding involves injecting two shots of materials to form the substrate and the overmold. Insert molding only involves injecting one shot of molten plastic, though the metal insert needs to be purchased or created separately.

Q: What is the process of overmolding?

A: Overmolding is a multi-step injection molding process where two or more components are molded over top of one another. Overmolding is sometimes referred to as two-shot molding because it is a two-step process.

Q: What are the applications of insert molding?

A: Examples of insert molding applications include manufacturing rods, electrical wire harnesses, threaded components, or knife blades. The main use of insert molding is to create a strong and reliable molded part with a very low investment of money and time.

As one of the most professional overmolding companies in China, we're featured by good service and competitive price. Please rest assured to buy cost-efficient overmolding from our factory. Contact us for custom service.

Plastic Overmolding Services, Silicone Overmolding, Overmolding

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