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Optimizing die-casting operations with DMLS by EOS

EOS Additive Manufacturing can integrate tempering channels in a tool directly and in near-contour conditions, thereby optimising heat diffusion. This facilitates higher productivity and part quality in die-cast serial production.

One of the major challenges in die-casting is the defined cooling of the tools used during serial production. This is where conventional tool production processes reach their limits: Tempering channels can only be drilled in straight lines. This means that critical hotspots can often not be reached with coolants and thus cannot be relieved. As a consequence, the tool can become misshapen and its service life will be reduced. In addition the partly deficient heat dissipation is responsible for long cooling times for the manufactured products.

Innovative Additive Manufacturing from EOS on the basis of DMLS (Direct Metal Laser Sintering) is the answer: This makes it possible to integrate optimized tempering channels in the tool directly and under near-contour conditions during production. This means that heat can be dissipated much after and more evenly, while hotspots can be cooled on a targeted basis. Manufacturers benefit from numerous advantages: the tool retains its shape better and lasts longer. In addition, the plastic product quality and dimensional accuracy of the manufactured parts is enhanced, and drastically reducing cycle times.

Laser sintering technology irons out weaknesses

One example illustrates the huge potential of DMLS for die-cast serial production. The LBC laser processing center in Kornwestheim uses modern laser technology to offer its customers new solutions. LBC focuses on the area of mould making, in other words the manufacturing and final processing of moulds. The company either adapts parts to the process line or adjusts the whole process line to the customer’s processes. Thanks to the regular exchange of ideas with universities, research institutions and laser manufacturers, the laser process center is able to operate at the highest level using the latest technology.

LBC managed to design and manufacture a tool insert with significantly optimized tempering performance for a die-cast application. LBC constructed the insert from EOS MaragingSteel MS1 using the DMLS technique on an EOSINT M 270 laser sintering machine. During manufacturing, near contour tempering channels were integrated in the tool at defined points, significantly improving cooling performance. This enabled the manufacturer to reduce the cycle time by 20 %.

EOS Additive Manufacturing technology – Die-casting best-practice example

Tooling: FWB – Major Savings in Production Time and Cost Using Additive Manufacturing

Powerful EOSINT M 280 supersedes hybrid solution of the tool insert

To ensure that Germany remains an attractive location for the production of injection-moulded tools and plastic components, toolmakers and component producers rely on innovative technologies and procedures that save time and minimise expense. For years, Eastern European producers have been able to supply tools and injection components at lower prices than the so-called high-wage countries, and now they are being joined by more and more suppliers from the Far East. That is why German plastics processors need to make as much use of innovative and economic processes as they can, to be able to meet this cost pressure effectively. FWB Kunststofftechnik GmbH has been working closely with LBC LaserBearbeitungsCenter GmbH, a producer of metal parts using Additive manufacturing. This cooperation has resulted in the present method for realising tool inserts for injection-moulding components.

Challenge

The project at hand was to manufacture mould cores for a 16-core production tool intended for the serial pro- duction of injection-moulded plastic components. The requirements placed on such components derive from the situation in Eastern European injection moulding production facilities described above. Product life cycles are becoming increasingly short, resulting in the need for greater flexibility in tool construction. It is of great importance that a fast and inexpensive method of devel- oping and realising moulds be employed and that it be suitable for use in highly automated, independently operating produc- tion cells. In other words, not only is it necessary to provide tools quickly and cost-efficiently, but they must continue to work with high precision over long periods of time.

Solution

In September of last year, LBC incorporated a new EOSINT M 280 laser sintering system into its manufacturing process. As a result, the company is now able to produce laser sintered components not only faster but also more cheaply, with a laser output that has doubled from 200 to 400 watts. The company is now able to weld tool steel 1.2709 in a variety of layer thicknesses more homogeneously than ever before. This increase in productivity offers interesting new perspectives for LBC customers’ tool and mould construction activities. As a manufacturer of tools and plastic components, FWB is one company taking advantage of this.

At the time of FWB’s initial request, LBC proposed a cost-optimised hybrid solution. FWB needed to produce a hybrid blank for a mould insert with the maximum possible volume. First, LBC calculated the structure of the cavity to fit the capacity of their EOSINT M 270. After integrating and configuring the EOSINT M 280 unit, the project was recalculated and two of the 16 tool cores to be made for the new production tool were constructed on the new system.

Results

Inserts produced using the laser sintering technology have distinct advantages over conventional mould inserts. There is no other process that allows such flexible placement of the cooling channels in the tool inserts, so close to the component contour. The benefit of this is a more precise and uni- form cooling pattern. Ralph Mayer, Managing Partner at LBC GmbH, explains: “The cycle time and the quality of the parts are also better than if tools with conventional cooling were used.”

Another advantage is the greatly reduced post-processing. In the case of FWB, the inserts only had to undergo a single final processing stage of smoothing, to bring them fully in line with the company’s quality requirements.

It was primarily the fact that these fully laser sintered compo- nents required only minimal post processing that made the decision-makers at FWB take a closer look at their overall costs. This revealed the following additional benefits: The fully Additive manufacturing method for tool inserts turned out to be 25 % more economic for FWB than the original hybrid solution. The new laser sintering system saved them four weeks in produc- tion time. Moreover, the compo- nent structures displayed consid- erable stability compared with hybrid components, which would have been made up of two parts. It was no longer necessary to create a permanent joint between the pre-produced metal and the joined-on laser sintered section.

As a result of these findings, the production tool was finally manu- factured in an additive process using the EOSINT M 280. Using the more powerful system for production clearly demonstrates the financial benefits of the new manufacturing method, both for FWB as a customer and LBC as producer. Ralph Mayer also notes: “What we have here is a classic win-win situation. Thanks to the new machine technology, we are able to supply our custom- ers even more flexibly, and our customers also profit in terms of time, cost and quality. In this way, we are ensuring that our customers feel well looked after, benefit all around from our expert know-how, and maintain their faith in us for many years to come.“

“Another reason for the success of the cooperation with LBC is that both the management and the employees always think flexibly when it comes to finding alternatives to existing production processes. The specialists at LBC showed us a new production alternative with the EOSINT M 280, which has given us optimum results coupled with reduced time and production expenditure.“

Michael Gerich, Head of Tool Management Department at FWB Kunststofftechnik GmbH

“By integrating the new EOSINT M 280 into our production, we were immediately able to offer customers a time- and cost- efficient alternative to hybrid component production. By directly transferring our con- struction data to the

machines and performing the complete manufacture, even of compo- nents with large dimensions using laser sintering technolo- gy, our customers are able to benefit from valuable time and cost advantages in contour-near tool tempering.“

Ralph Mayer, Managing Partner of LBC LaserBearbeitungsCenter GmbH

Short Profile

FWB Kunststofftechnik GmbH stands for innovative developments and technical expertise in plastic injection-moulding technology. The company‘s fields of activity include injection-moulding tools, automation, and plastic components.

LBC LaserBearbeitungsCenter GmbH supplies tool inserts made using Additive manufacturing for tool and mould construction. The company possesses specialised know-how in the fields of contour-near tempering and thermal dimensioning of injection-moulded and die-cast tools.

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