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Plastics application

What is overmolding and what you should know about it

29 April 2021

Overmolding is a modern technological process used to combine two materials whose parameters often differ significantly from each other. It is a technique that works well for manufacturing car parts with specific technical parameters, while also supporting production automation at the same time.

Industry 4.0 uses advanced, green solutions to meet the needs of today's supply chain. One of them is overmolding, which speeds up production, simplifies component assembly, and supports even the most challenging automotive parts projects.

What exactly is overmolding?

Overmolding is a process that allows the creation of elements with precisely tailored parameters, which are the result of the combination of two different materials. This innovative processing method allowsto significantly reduce costs of produced elements. Combining materials with different parameters, especially in case of plastics, is not always possible. Often the final result of overmolding is to provide a structurally coherent element, which combines metal and EPP foam. Polypropylene foam, or EPP, is characterized by its low weight and high recyclability. It also provides excellent amortization, which makes it an effective support for the metal structure. It is also distinguished by its outstanding flexibility – it can take virtually any shape, because the components are usually created by molding.

For car manufacturers, these parameters are invaluable. Designing vehicles using such a material becomes much simpler, and the construction itself, especially the interior of the vehicle, can contribute to more ecological driving. Another advantage is the optimization of production and the possibility to deliver components with ideal parameters.

See also: Automotive components – Knauf Automotive’s offer 

What is the application of overmolding?

Overmolding is used in many market sectors. One of its greatest advantages is the ability to create ready-made components in the automation process. This eliminates the need for additional assembly using plastic screws and the need for ultrasonic or spin welding. Overmolding is usually an automated process, therefore it allows to maintain repeatability and precision. Details are very important not only in terms of aesthetics, but also the final specification of the product. Overmolding makes it possible to obtain a structure which is distinguished by a very strongly defined border between the materials used. It is also distinguished from other methods by its durability, versatility and the possibility of using ecological materials. Successful implementation of this method can significantly reduce the cost of creating finished components. By pairing this technology with modern Industry 4.0 solutions, it is possible to significantly reduce the time to market for a given product, as well as increase production flexibility by being able to make adjustments to the form according to which a component is created.

Overmolding is considered to be a very effective process. It ensures perfect parameters of the final element, and the effective implementation of this technique into the production process can bring great added value in the area of cost reduction and increasing the efficiency of creating new components. Among the benefits of its application, it is also necessary to point out the increase in durability of elements, enhancement of visual values of the parts and weight reduction with simultaneous stiffening of the product. The last aspect is particularly important in the automotive industry, as it has a direct and positive impact on driving physics.

See also: Injection mold design, tooling and manufacturing with Knauf Automotive – from design to finished product

Overmolding and the automotive sector

The overmolding process is often used in the production of components for car seats, as well as many other parts. It can be used in the creation of headrest components, vehicle structural reinforcement frames, energy absorber mounts, and more. These are components that, prior to the widespread implementation of overmolding, were mostly made of metal due to the need for durability. The aforementioned features of lightweight foam elements combined in the frame in overmolding process are, in this case, very desirable. While maintaining high resistance to forces associated with the physics of driving, components made using overmolding are lighter and better suited to the parameters of the vehicle structure. Molded automotive components require modern models of material behavior to be considered at the design stage, taking into account numerous factors related to vehicle movement. While this presents some challenges, it is not a significant obstacle to modern manufacturing standards.

Preparing the tools to enable overmolding and coordinating production are quite challenging tasks. However, the successful implementation of this technological process with the appropriate knowledge and support from trusted partners can have a significantly positive impact on vehicle performance. The systematic development of innovations related to foamed polypropylene is also beneficial from the perspective of production ecology. This material is recyclable and allows for free adjustment of parameters to the needs of a given design.

Why should you choose modern solutions from Knauf Automotive?

Our extensive knowledge, access to state-of-the-art tooling facilities with our team of experts, and the extensive experience we have gained in implementing innovative processes enable us to efficiently support the coordination and design of overmolded parts. At Knauf Automotive, we place great importance on ensuring that such demanding processing methods are able to deliver the highest possible added value to the customer.

For many years we have been working with components made using environmentally friendly plastics, such as EPP foam automotive components. The molding tooling we develop is the result of a multidimensional analysis in which we examine the behavior of the specific material in the customer's design and perform a risk assessment of the component.

One of our hallmarks is the use of a highly efficient and automated production lines. We use the latest robotization solutions, such as 6-axis robots that produce seat-mounted components. The machines operate efficiently and precisely, to a great extent eliminating potential human error. We also focus on error prevention – when the robot detects any inaccuracies, the appropriate people on the production line are automatically informed. As a result, we are able to eliminate most of the common problems associated with the adaptation of production using overmolding, thereby ensuring a rapid start-up of production and the production of a large number of components with the desired properties without delay.

Contact us for more information about tailor-made solutions for your project in  automotive sector. 

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