Industrial Successes

Learn how AddUp worked with German toolmaker Gira to modify an existing mold to achieve shorter cycle times and improved heat conduction using additive manufacturing. 

INDUSTRY

Tooling & Molding

CHALLENGE

It was difficult to find a potential project at Gira, since most of the sockets and switches are produced  with a high-gloss finish, something the AM community hasn’t tackled yet.

We found an intriguing application in a socket variant for surface mounting. Due to the core on the locking side cannot  be sufficiently tempered by conventional means. There is no way for machine channels to homogenously cool the part across the height of the mold.

KEY BENEFITS

• Improvement in temperature control
• Reduction of cooling time
• Understanding AM Specific Design Approaches

INCREASED PRODUCTIVITY

REDUCED MANUFACTURING TIME

CONFORMAL COOLING

History

Gira’s toolmaking stands for the innovative production of technically high-quality products and assemblies with industrial precision. A particular strength lies in the great speed and flexibility with which they create solutions for large series, small series, and prototype tools, all cost-effectively. Gira is also capable of creating tools for multi-component molded parts.

The aim of this project was to modify an existing mold to achieve shorter cycle times with the core of the part now being designed to be produced by AM.

With the existing mold, the part can be produced to the required quality specifications, but the conventional cooling of the mold core results in  suboptimal heat conduction. Eventhough the cycle time is already in an economic range,  Gira noted  that further improvement can be made in this area.

There lies the potential to improve heat conduction in the core through an improved cooling channel design, and thus a reduction in the  cooling time is made possible through additive manufacturing.

Challenge

The end-use part produced by the mold is a polycarbonate socket, and has a wall thickness of approximately 3mm. The core of the insert has a large contact area with the polycarbonate andthis entire surface must be cooled homogeneously in order to achieve optimized heat conduction compared to the conventional core. In order to achieve largely uniform heat dissipation, it is imperative to design the cooling channels with equal spacing to the respective surfaces and to properly choose the spacing between the channels.

Following these rules leads to  highly effective cooling but there are other manufacturing considerations to be taken into account. After the 3D printing process, the part must be thoroughly depowdered, and as the complexity of the circuit of cooling channels increases, so does the complexity of depowdering of these channels. This step in the process chain is critical to both the functionality of the part and the safety of workers exposed to the powder.

Delivering flawless parts and protecting workers is AddUp’s priority.

Solution

The geometric properties of the core were used to inspire the design of the channels. There is an axis of symmetry in the core around which a channel can be mirrored. This feature is more often used to save construction costs, but is also convenient in achieving perfect balancing of the ducts, since they can all be modeled in the same way.

Since this core is built into an existing mold, the cooling inlets and outlets are predetermined. To supply the four channels with coolant, a quadruple parallel circuit is built into the core. In this way, it is possible to connect all the channels to the existing coolant supplies.

In the process of designing the channels, de-powdering must be considered. The alignment of a part on the 3D printing platform is determined by its geometry, the desired tolerances, and the amount of support structure. In the case of this core, the optimal orientation is obvious due to the recess for the plug and the angle for demolding. However, this alignment has the disadvantage of making the part difficult to depowder because the inlets and outlets are located on the plate.

To ensure that the operator does not come into contact with powder, only properly de-powdered parts can be removed from the  confined zone. In this zone, the operators are equipped with protective clothing and respirators, PPE that is not required in the rest of the process chain.

In order to thoroughly de-powder the fourfold parallel cooling system, the component must first be sawed off the build platform. To prevent loose powder from escaping from the component, an orifice plate was installed. That orifice plate wasn’t removed until the component was back in the powder zone, preventing any powder from escaping until ready to thoroughly de-powder the part.

This project is a good example of a very complex component being depowdered without compromising safety, because the safety of the employees must always be the top priority.

Results

An improvement in temperature control are guaranteed by employing intricate complex conformal cooling channels using the design freedom of AM. This project shows that designing molds with AM in mind can lead to ample downstream benefits. Gira will be exploring opportunities in their early development stages knowing they can use AM to increase performance of their molds. Gira and AddUp will continue to work together as they find more and more applications where AM can help their customers.

• Design of parallel and balanced cooling circuits.

• Stock material as small for post-processing

   

   

• Addition of references and clamping surfaces

The goal of the project is to verify the technical and economic feasibility of additive manufacturing of complex geometric replacement parts for equipment that is no longer manufactured.

The project aims to verify the technical and economic feasibility of producing additive manufacturing spare parts with complex geometries for equipment that is no longer manufactured and historically sold complete. The equipment in question is a material transfer bridge and a steam distributor block.

Context

Different plants in the Orano group want their spare parts to be available at the right time and at a lower cost, to secure the installations and optimize their parts inventory management. In particular, the maintenance department of Orano Cycle Tricastin has to deal with the obsolescence of some equipment for which the supply time is very long. In the nuclear industry, the storage of spare parts for all those complex equipment represents an important investment.

The Project

The project aims to verify the technical and economic feasibility of additive manufacturing to produce metal parts with complex geometries for equipment that is no longer manufactured and historically sold complete. The equipment in question is a material transfer bridge and a steam distributor block.

To meet this demand, Orano needed to rely on a solid industrial group with a large machine pool and a mastery of the value chain. This is why Orano called upon AddUp, a French manufacturer of metal additive machines. The AddUp experts thus 3D printed, using PBF technology (Powder Bed Fusion – laser), nine models of 316L stainless steel parts as well as test specimens for mechanical tests (tensile and impact) and other quality controls.

Additive Manufacturing Benefits

• The cost of additive manufacturing compared to machining is lower: less material consumed, several parts printed on a single platform, and in a single operation.
• The ability to produce parts with complex geometry from a scanned model of the part (reverse engineering) for parts without a CAD file.
• The use of fine powder results in parts with high geometric accuracy and a good surface condition, even in internal channels.

Results

The full cost of producing 16 parts and 36 mechanical test specimens by additive manufacturing is equivalent to the cost of producing 3 parts by machining.

The AddUp Advantage

The use of fine powder with the FormUp350 machine allows for manufacturing parts with a good surface finish (especially for internal channels), as well as the creation of complex geometries. Control of the complete production chain: design, production, machining, post-processing, and inspection.