Germany-based Anderson Europe was formerly Elmar Wessel Präzisionsmaschinenbau, a family business that became part of the Anderson Group. The company has been developing and manufacturing high-precision machines for various industries at its headquarters in Detmold for six decades. The earliest of these machines produced microdrillings in printed circuit boards (PCBs) for the semiconductor industry. Today, Anderson Europe is a leading global provider of HSC milling, die production and multi-axis machines used for a variety of other purposes.
Anderson Europe’s ProSys ADV+ 5-axis high-speed milling machine. There are also 3- and 4- axis models of the ProSys ADV+.
One such purpose is the microengraving of date stamps for injection moulds. These engravings are best produced using high-precision, CNC-controlled milling machines that incorporate a high-resolution camera for positioning and calibrating the components, such as Anderson Europe’s ProSys ADV.A date of manufacture can be found on every injection moulded part. A stamp is integrated into the injection mould to emboss the date on the part. The production of these stamps is a challenge that should not be underestimated, as the individual digits in the smallest ones are only a few tenths of a millimetre in size.
Date stamps are usually produced in diameters ranging from 2.6 to 16 mm. However, increasingly even smaller date stamps, with diameters of less than 2.6 mm, are required for the tiny injection moulded parts produced by industries such as medical technology and semiconductor. (Image 2)
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Microengraved numbers produced on a date stamp using Anderson Europe’s ProSys ADV.
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Microengraved numbers produced on a date stamp using Anderson Europe’s ProSys ADV.
A case in point
An Anderson Europe customer required a date stamp with a diameter of only 2 mm engraved with the digits 1 to 12. This meant that the individual digits needed to be 1 pt or 0.35 mm in size. Moreover, using a special tool with a diameter of 0.06 mm provided by the customer, the numerals had to be engraved 0.09 mm deep into the blank, which was made of tool steel.
Anderson Europe’s many years’ expertise in punched sheet production was successfully applied to this project. In addition to high demands on the positioning accuracy of the numerals, the legibility of the numbers had to be ensured. Numbers could not be engraved on the 2 mm date stamps because they would have been too small, so it was decided that line markings would be used instead.
Anderson Europe used the ProSys ADV’s high-resolution smart camera mounted on the Z-axis when positioning the blanks inside the machine. The camera was used to reliably calibrate the pre-existing centre hole in the blank in an automated manner, then arrange the digits evenly around the circumference. The 1-9 and 10-12 numerals were positioned 0.3 and 0.2 mm apart, respectively.
The tool was especially challenged because the milled numerals had to be completely burr-free along the edges, and this had to be achieved without reworking of the components. With the aid of a cooling medium, the milling result was further refined and wear on the tool reduced.
The size of the components places demands on the clamping of the parts, especially in the case of series production of these date stamps. To be able to work efficiently, the blanks were clamped positively on pallets and then fed to the machine by means of a zero-point clamping system. A limit in the mould also prevented excessive clamping force from being applied to the part.
Numbers being microengraved on a clamped date stamp
A reliable series process was implemented by using the high-resolution smart camera to check the engraving result directly in the process and evaluate it using a specially learned algorithm. The excellent positioning and repeat accuracy of the machine as well as the ability to integrate adaptive measuring instruments in the process were the guarantors of success in this project. Underpinning these is the machine’s base made of granite base, which minimises vibrations while offering very high rigidity and thermostability.
Anderson Europe’s consistent consideration of dynamic workpiece properties during metal-cutting machining means it is possible to machine a wide variety of materials, including aluminium, carbide, plastics, ceramics, Kovar and Invar. In addition, the modular design of the machine offers automation solutions such as the >ProMag< robot cell for flexible workpiece handling. These factors allow for the 3-, 4- or 5-axis machining of components within µm tolerances.
ProSys ADV developments
In September 2022, Anderson Europe introduced a new version of the ProSys ADV. The main objectives of the machine’s redevelopment were user-friendliness and automation. All considerations for optimisations were initially thought about from these perspectives. Thus, the machine not only impresses with a completely new design but a significant increase in machining process flexibility. For example, part of the basic equipment is a robot magazine that can accommodate both tools and workpieces. Tools are loaded into the magazine in a user-friendly manner via a changing station on the side of the machine. In addition, software input is performed with the aid of a handheld control unit, which can also be used for the setup process. A particular advantage of the robot magazine is that loading can also be carried out during the machining process.
Anderson Europe