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Injection molded parts with graphite – the best of both worlds

Innovative manufacturing process for cost-efficient automotive components in large volumes


Regardless of the type of car, reliable thermal management is essential to operate all systems in the vehicle within the optimum temperature window. Pumps with bearings and seals are needed for the smooth transport of fluids, such as cooling water. To ensure high chemical, thermal and mechanical resistance of these components, Schunk has developed a production process for components that are not only particularly efficient and durable, but can also be manufactured in large quantities and complex geometries.

A new graphite injection molding process combines the advantages of graphite materials with those of injection molding. The result is, for example, bearings for cooling water pumps that are particularly resistant and have optimum lubrication properties.

Schunk experts Matthias Kienholz and Patrick Rauber explain the advantages of the process and how it works in our free whitepaper "Injection molded parts made of graphite: innovation for e-mobility." Download the document to learn, how even complex geometries can be produced in large quantities using the graphite injection molding process, and how the parts can be adapted to individual requirements by the customer.

Read our expert's answers to FAQ about our graphite injection molding process here:


Mr. Rauber, what are the advantages for customers who opt for graphite-based pump bearings?

Patrick Rauber: The life cycles of pumps running with our graphite-based bearings are significantly longer. In addition, the innovative process allows us to produce six to eight parts at a time. Furthermore, the temperature resistance is up to 180 degrees Celsius, and even higher for short periods. Overall, we create more and more durable components in the same amount of time and are significantly cheaper than the competition.

What is the minimum number of parts per year for the injection molding process to be cost-effective?

Matthias Kienholz: The minimum number of parts is 500,000 per year. But this figure also depends on mold costs and the number of cavities. For lower quantities, we offer alternative manufacturing processes such as machining or compression molding.


Why are customers from the automotive industry at the right address when they are looking for a way to source components in large quantities cost-effectively and in series?

Patrick Rauber: For customers, it can sometimes be difficult to decide who the best supplier is. After all, cooperation is not just about low costs. We also impress customers with the high quality of our materials, our many years of expertise in materials and processes, and the services we provide in connection with the planning and manufacturing process. Anyone who wants to assert themselves in the automotive industry environment also has to be fast. Quality, cost efficiency and speed are therefore crucial. That's why our customers choose to work with Schunk.

You mentioned speed. How long does it take from the inquiry to the delivery of a tool part?

Matthias Kienholz: That basically always depends on the quantities, the tolerances and the geometries. But normally we are talking about a period of six months here.

injection-molded-partWhat challenges are you and your team currently facing?

Patrick Rauber: The automotive industry demands components in high volumes. Depending on which source you follow, experts expect up to 80 million hybrid and electric cars to be sold in 2040. And even if we fall short of this estimate, we are still talking about immense annual quantities for our components, which we have to provide "just in time".

With injection molding, we can produce high volumes and are therefore not only time-saving but also cost-efficient. However, in the future, we want to reduce the sprue and optimize disposal in order to be able to produce more sustainably overall - a requirement that is currently driving all industries.

Why do you rely on graphite materials for your products?

Matthias Kienholz: This question is very easy to answer: graphite masters the well-known challenges in the automotive industry. So when applications don't work with metals, plastics or other materials, you should ask for carbon, graphite or ceramics.

Which challenges do you mean exactly?

Matthias Kienholz: Friction losses, for example. These are undesirable, of course, because they are associated with high temperatures or wear. In some applications, however, the use of lubricants such as grease or oil is not possible due to the temperatures, or the parts cannot be maintained due to their location. Other well-known challenges include low weight, resistance to corrosion or oxidation under aggressive media, and, increasingly, complex geometries.


And how can graphite-based components overcome these challenges?

Matthias Kienholz: Here we benefit both from the material properties of graphite and from our various manufacturing processes. We can offer materials with a low coefficient of friction, excellent dry running properties, high resistance to aggressive media or high temperatures. In addition, our materials offer low density and are therefore often lighter. Lightweight construction is a key to more efficient mobility.

For which pumps are components made of graphite injection molded materials best suited?

Patrick Rauber: Due to the properties mentioned, our material is the right solution for almost every pump application. Wherever maximum sliding properties or aggressive media are required, our materials and manufacturing processes are a perfect fit. For example for

  • water pumps
  • fuel pumps
  • coolant pumps
  • seals and bushings.

Download White Paper "Injection molded parts"


Matthias Kienholz
Global Business Development Manager MCA
+49 641 608-2312

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