Insert molding

Insert molded parts made from high-performance plastics

Insert molding is a special injection molding process in which we mold a thermoplastic around a prefabricated insert, usually made of metal, ceramic or another material. This technique enables the seamless integration of components, eliminating the need for assembly after molding.

Unlike overmolding, where a secondary layer is applied to an existing plastic part, insert molding integrates a specific insert – such as a fastener, sensor or electronic component – directly into the molded part. For applications that involve metal insert injection molding or metal insert molding, the result is a strong bond between materials with excellent performance.

We start the process by placing the insert into the mold cavity, which can be done manually or automatically using robot technology. Once positioned, the mold is closed and molten plastic is injected into the cavity, encapsulating the insert and forming a single, connected component. This ensures precise alignment of the insert while preventing displacement during molding. The design of the mold cavity is crucial, as it must take into account the positioning of the insert and ensure a consistent flow of plastic around it.

Since we at Ensinger provide support from the initial idea, through design and component construction, to prototype production and subsequent series production, we always know where to start in order to guarantee the highest quality standards.

Advantages of insert molding

Higher mechanical load capacity

The insert molded parts take on loads, which relieves the plastic and increases its strength
Particularly suitable for highly stressed components in electrical engineering, medical technology and lightweight construction

Increased durability and resistance, improved insulation

Better resistance to shock, vibrations and corrosion
Ideal for sterilizable plastic housings in medical technology
Protection of sensitive electronics from environmental influences through encapsulation
Electrical or thermal insulation through the use of plastics

High precision

Inserts are positioned precisely so that holes, threads or functional areas can be integrated directly into the component
Prevents misalignment and enables complex geometries

Optimized production and reduced costs

Elimination of additional assembly processes through direct integration of metal inserts in plastic parts
Lower overall weight, as additional connecting elements are no longer required
Greater production efficiency thanks to less material waste and automated processes

Insert injection molding enables the production of hybrid components with high strength, precision and efficiency. Particularly suitable for applications with high load requirements, it offers an economical alternative to conventional assembly processes.

Industries and applications of insert molding

This process is frequently used in sectors such as the automotive, healthcare and electronics industries, where durable, lightweight and high-performance parts are required. Applications include insert molded parts such as housings for medical devices and gearboxes for motor vehicles.
Insert molding is typically used for bearing applications. Strict tolerances could not be met if molded solely in plastic, but the combination of metal and plastic can, making the application lighter and more cost-effective to manufacture.

Our expertise in insert molding technology

For manufacturers looking for solutions in insert injection molding, working with an experienced insert molding factory or insert molding suppliers is key to achieving precise, high-quality results. Whether you're looking for insert molding suppliers for prototypes or high-volume production, choosing the right partner will ensure cost-effective and durable components.

As an experienced insert molding partner, Ensinger offers high-precision solutions for a wide range of applications. Our plastic insert molding parts impress with their precise processing, durable material combinations and top quality. Whether it's heavy-duty hybrid components, metal overmolding, or specialized industrial parts — with Ensinger, you can rely on durable, innovative solutions.