Design offensive in mould construction for the automotive industry: unlimited possibilities in surface design
Date posted: November 5, 2013
See SAUER Gmbh / DMG / MOR SEIKI on Stand A115
Repeat accuracy of 5-axis milling, laser texturing and laser coating ablation on one precision machine: The LASERTEC 65 Shape sets new standards in mould making.
The time of simple leather grains for automotive interiors has passed, just like that of standard textures of many consumer goods. Thanks to the innovative technology of 5-axis laser texturing on the highly precise and long-term stable high-tech machines of the LASERTEC Shape series of DMG / MORI SEIKI, designers of demanding exposed surfaces are no longer limited in what they can achieve. Geometrically defined surface structures in 3D free-form areas, for example, for interior automotive components such as fittings, steering wheel caps or engine covers, can be manufactured with the highest contour precision in reproducible quality. In addition, the integration of the flexible LASERTEC technology by means of the HSK interface in a 5-axis milling machine enables milling and laser texturing technology to be intelligently combined on one machine.
The interaction of laser power (fiber laser up to 200 W power output), the possibility of contour-parallel laser shaping (depending on the 3D contour of the component, the laser focus can be shifted extremely dynamically to the Z-axis), and the quick surface calculation of the software, enables unbeatably quick 5-axis laser machining.
Extremely compact 5-axis precision machine tool guarantees long-term stability:
As the latest model in the Shape series the LASERTEC 65 combines proven 5-axis milling technology based on the high-performance DMU 65 monoBLOCK® with the possibility of 5-axis laser precision machining. So productivity and precision already start during milling of the mould parts. A compact cast stand in monoBLOCK® design ensures absolute stability and rigidity and this in turn guarantees long-term accuracy. The machine has been designed to take up as little space as possible – it has a footprint of only 7.5 m² – and offers optimum access to the large work area. This measures 650 x 650 x 560 mm and a door opening of 1,430 mm that means it can be loaded at any time from above with a crane. So in the case of the 5-axis machine version with integrated NC swivel rotary table, injection moulds measuring 840 mm in diameter and 500 mm in height and with a workpiece weight of up to 1,000 kg can be brought into the work area with no problem at all. With the 3-axis machine it is even possible to machine components weighing up to 1,800 kg.
Technological combination of milling and lasering on a single machine:
The heart of the LASERTEC 65 Shape is a laser scanner that can be integrated flexibly into the machine via an HSK interface, so that even highly complex mould components can also be laser textured in the same setup immediately after milling. Implementation of the HSK laser head is effected by means of a special manual changeover arm next to the machine that allows the changeover from milling to laser operation in just 10 minutes. The flexible LASERTEC technology integration is possible in all monoBLOCK® and duoBLOCK® milling machines from DMG / MORI SEIKI. This highly innovative way of machining the surface of synthetic injection moulds beats conventional etching applications by far. In contrast to ecologically harmful etching technology, laser texturing allows even highly complex, geometrically defined 3D surface structures to be lasered into free form surfaces with no problem at all and with top repeatability. So virtually any imaginable visible surfaces can implemented to customer specifications, from a simple leather structure in a mobile phone shell to a 3D scale structure in a shoe sole and on down to a geometrically-defined pyramid structure in a steering wheel cap.
Digital process chain: from the bitmap to the laser structured injection mould:
The structure data required for lasering are created on the basis of grey-scale bitmaps. This is followed by so-called mapping, whereby an even and as far as possible distortion-free raster image is mapped onto the 3D surface of the part to be structured. An external 3D software is needed to do this, similar to that needed for animated films. In principle the structure is pulled over the geometry of the tool form by the computer rather like a „rubber skin”. The same software then transfers the previously created surface structure onto this mapped 3D surface. Fine tuning, especially of complex free form surfaces, is carried out using an image editing software. Finally the user-friendly software feature LASERSOFT-3D-TEXTURE converts the created structure data for actual machining, generates the CNC machining programs, simulates the machining in 3D in advance and positions the workpiece in such a way that the laser beam always hits the surface at an ideal angle. The user is supported here by the high-performance CNC control Siemens 840D solutionline with its DMG ERGOline® panel and 19“-TFT screen.
Contour-parallel laser shaping:
Significantly faster laser machining with increased quality can be achieved with the innovative option “contour-parallel laser shaping”, especially in the case of component sequences that are difficult to reach. The integration of a so-called Z-shift here makes it possible to move the laser focus very dynamically on the Z-axis. This is realised via a fast-moving lens in the optics. The great benefit here is that you do not have to re-adjust every track that has to be lasered with the laser head or the complete workpiece on the Z-axis. This means that many injection moulds can be textured up to twice as fast as they can be with anything the competition has to offer.
In addition the machines in the LASERTEC Shape series are equipped with fibre lasers with up to 200 Watts. The use of more powerful lasers means that significant increases in productivity can be achieved for some selected materials such as aluminum or castings, for example.
The larger LASERTEC 210 Shape model represents an upward expansion of the product range. “This hybrid model is ideal for customers who cannot utilize a laser machine to full capacity, but nevertheless still wish to offer both milling and laser technology,” is how LASERTEC Sales Director Friedemann Lell describes the target group. Workpieces with diameters of up to 2,000 m and weighing up to 10 t can be machined on the LASERTEC 210 Shape.
To sum up, it can be said that precisely this combination of laser performance, the possibility of contour-parallel laser shaping and the fast surface calculation of the software all add up to allow unbeatably fast laser machining.