Flexible and cost-efficient machining of large composites, how do you do that?

In the aviation industry, the use of composites for manufacturing important large components is steadily increasing. Following this shift from metal to composites, the production processes for these components must be adapted as well. However, this evolution is not that obvious within the manufacturing industry as the current machining processes for composite components are insufficiently flexible and efficient. For example, the flexibility of composites is a major problem for the current machining technique. Complex customised and thus expensive clamping systems are needed to prevent splintering and delamination of composites. The size and shape of these panels often require the customised production of such supporting structures per piece or in small series, which turns it into a time-consuming and expensive solution.

The current trend towards smaller batches and mass customisation makes the flaws of these solutions even more acute. The result is that many machining companies just drill at a slower pace to limit the negative impact of any deformation. This obviously results in a lower productivity and still doesn’t always prevent fraying at the edges. So, we need simple and easily adjustable methods to support large composite panels for machining operations.

Innovative solutions

For this reason, Flanders Make and its partners have developed some innovative technologies to make the machining process of large composites more flexible and cost-effective.

Vibration-supported drilling and machining

This means high-quality drilling and machining operations on composites with adjustable Automatic Drilling Units that control applied force and vibrations. This technology has a positive impact on the life span of the tool and on the speed of the machining operations.

Cryogenic cooling method and use of specific cutting tools and coatings

The innovative cryogenic technology uses sub-zero cooling to compensate for the high composite machining temperatures. This also increases the life span of the applied tools and improves the quality of machined components.

Furthermore, Flanders Make and its partners performed research into the coatings and geometries of cutting tools and optimised them. As a result, these tools can be used longer and machining costs can be reduced.

Patented smart clamping system

When machining large composite panels, it is important to stabilise the panels to secure the best possible quality. The larger the panels, the more they will bend, vibrate or bounce back. Customised fixtures or modular suction systems can remedy this but are very expensive and difficult to design.

The ‘smart clamping system’ of Flanders Make offers a good solution for this. This technique provides local support to the panel with a few suction caps along the cutting side. In this way, adapted fixtures are no longer necessary to support the bottom side. The Smart Clamp provides support according to the machining locations, which results in high-precision machining operations and strongly reduced bending (and, accordingly, less splintering and delamination).

It is a very flexible and accurate technique and can thus be used in many different industrial settings. Both large and small shapes can be configured with it. As the suction system can be easily replaced, the Smart Clamp can also be used for milling flexible materials.

Major advantages

These innovative technologies offer several advantages:

• The biggest advantage of this innovative technology is the fact that the smart clamp can be mounted on existing CNC machines so that no changes to the infrastructure of machining plants are required.
• This not only applies to the hardware but also to the software. The module has been developed to operate without communicating with the CNC machine software or production planning. The smart clamp module entirely operates as a stand-alone tool. It will detect when the CNC machine approaches a work piece, clamp it, estimate the feed rate of the CNC machine and then determine how much force must be applied to compensate for the process forces. Finally, it will detect when the clamp must be released.
• These different techniques ensure a longer life span of tools, which may significantly decrease the production cost. It also takes less time to deliver high-quality composites and also the quality of the resulting work pieces is improved.
• Next to large components as are used among others in the aviation industry, these innovative solutions can be used for a wide range of machining operations and applications.

Do you want to know more about how these machining methods can be applied in your company? Please don’t hesitate to contact us so that together we can find the best possible solution for your specific applications.