Nowadays, there seems to be a lot of talk about micro over-molding. This probably means that there is an increased interest from manufacturers and designers in procuring and creating micro-featured and high-precision plastic components.
For those who don’t know, micro overmolding is a process where one part is produced using 2 or more materials in a combination.
This process helps protect sensitive parts or offer a better feel and look to the final product.
The first material is known as the substrate. The second material that covers the substrate is known as the oversold. Typically, the covering materials are elastomers or thermoplastics.
So, what are the practical applications of micro overmolding? Let’s find out!
Technologies Utilized for Micro Overmolding
Typically, there are 3 technologies that manufacturers use for micro overmolding. This includes low-pressure injection molding, multi-shot molding, and single-shot molding.
Low-Pressure Molding
Since the electronic industry is constantly growing, it’s extremely important for electronic manufacturers to protect fragile and weak parts.
Because of this, low-pressure molding has begun playing an important part in the protection of fragile electronic components. This process has replaced the need for traditional potting processes.
This modern protection process of weak electronic parts includes a micro overmolding process that manufacturers carry out using low temperature and low pressure. It also uses less time.
Multi-Shot Molding
In multi-shot molding, also known as two-shot molding, complex molded components are manufactured from two unique materials.
The final product will reach the end result in two subsequent and related steps. The molding machines that include 2 or more barrels and 2 materials are shot during the same cycle.
The manufacturer will feed the first material to the barrel to produce the product’s first form. Then, it enters the second barrel for the last build.
The benefit of multi-shot molding is that the component has better quality and labor expenses are lower.
Single-Shot Molding
Single-shot molding, also called insert molding, is the most common process when it comes to micro-overmolding.
First, a pre-molded insert is installed inside a mold and the thermoplastic elastomer (TPE) is shot over it.
The advantage of single-shot molding is that it’s a little quicker compared to traditional injection molding.
This is because single-shot molding provides the simultaneous molding of two plastic materials. In addition to that, the tooling expenses related to insert molding are also lower.
Unique Applications of Micro Overmolding
Toys
The toy industry greatly depends on the use of plastic molded components. The over-molded parts utilized in toys offer the required safety against external stresses.
A huge number of industries are utilizing molded components to manufacture the following products:
- Nonelectric games and puzzles
- Electronic toys
- Crafts and models
- Action figures and dolls
For instance, microplastic is one of the best toy industries that utilize molded components to produce toys. In the previous year, the company generated around $30 million in revenue.
Electronics
One of the biggest applications of micro overmolding in the electronics industry is wire over-molding.
A lot of components in the electronics industry are over-molded to ensure they’re shear-resistant, flexible, and durable.
However, single-shot molding is also commonly utilized for producing a single component with the combination of two materials. Because of this, manufacturers have to rely on a reliable circuit breaker supplier for a steady supply of power.
Wires, thermostats, circuit boards, and PCBs are commonly placed under the over-molding process to become strong against external factors.
Today, electronic silicon over molding is opening new doors for further development of over-molding in the electronics industry.
According to reports, the market size of molded components in the electronics industry will reach $1.11 billion by the end of 2029.
Automotive Industry
Today, manufacturers use over-molding to create accessories, handles, prototypes, and molded components under the hood of any vehicle.
The TOSCAA (Thermoplastic Overmolding for Structural Composite Automotive) project has changed how manufacturers use over-molded components in the automotive industry.
This association is headed by the University of Nottingham, AMRC, LMAT, Nifco, Jaguar, Land Rover, and SGL carbon fibers.
All of these partners have collectively gathered more than $2 million with the purpose of making vehicles faster, more durable, and lighter.
The global market size of molded components in the automotive industry in 2016 was $1.67 billion. However, according to reports, it will reach around $3.29 billion by the end of 2025.
Medical Industry
Medical injection molding has crucial applications in the medical industry. Over-molded medical devices consist of the toughness and rigidity of one material and a soft and ergonomic feel of another material.
The sturdy and flexible exterior of molded components lowers the possibility of abrasion. It also provides great water-resistant properties to protect against corrosion.
Properties of Inserting and Molding
For those who don’t know, inserting is a manufacturing process that mixes 2 materials to create a single product.
On the other hand, molding is a simpler process that follows easier steps.
However, a couple of factors can make molding and inserting a difficult-to-reach process. This includes jetting, burn marks, short shots, warping, sink marks, and flowlines.
Overmolding Complexity Overview
Micro over-molding is a little more complicated compared to traditional molding. First of all, the correct choice of over-molded material on the substrate is what makes it more complicated.
In addition to that, you will also have to take care of whether or not the over-molded component is properly sitting on the substrate. Because of this, you might need an injection molding chair while you wait.
What is the Overmolding Process?
The overmolding process involves molding a material, typically a soft or elastomeric substance, over another pre-formed part. This method is commonly used in manufacturing to enhance the functionality, aesthetics, or durability of a product. The overmolding process usually occurs in two steps:
- Insert Molding: First, a base or substrate (usually a rigid material) is created through injection molding. This initial piece is referred to as the insert.
- Overmolding: The insert is then placed into a different mold, and a second material, often a softer or more flexible polymer, is molded over it. This creates a single, integrated component with the benefits of both materials.
Key Aspects of Overmolding:
- Materials: Overmolding allows for the combination of materials with different properties, such as a rigid plastic combined with a rubber-like material.
- Enhanced Grip and Comfort: Overmolding is often used to add ergonomic features to handles or grips, improving the user experience.
- Sealing and Protection: The process can also be utilized to create a protective layer, enhancing resistance to moisture, chemicals, or impact.
- Aesthetics: Overmolding can contribute to the visual appeal of a product by incorporating different colors or textures.
- Reduced Assembly: By combining multiple components into one during the molding process, overmolding can streamline assembly processes and reduce production costs.
Conclusion
Micro overmolding has become a globally adopted and renowned approach for producing components that are typically prone to external stress.
Overmolding has developed in all major industries, such as the toy industry, electronic industry, automotive industry, medical industry, and much more.
While the process has particular complexities, it is still the most suitable method to protect frail and weak components.
