Milling machines are generally designed to be operated by experienced and highly qualified skilled personnel. The Datron dental milling machines are an exception, since they possess the full functionality of a 5-axis machining centre, but must be set up, adjusted and operated by laboratory technicians. Combined with the high cost and productivity pressure under which dental laboratories often work, an unsuitable machine control system can lead to high mental stresses for the workers. For this reason, the Datron control concept was revised and simplified.
Standards relevant to milling machines and machining centres can be found on NoRA by use of the following search terms:
The Technical Report ISO/TR 22100-3 describes how ergonomic principles can be applied during the risk reduction process according to ISO 12100 and how ergonomics standards can be applied to machinery. It helps designers take decisions with respect to ergonomics during the machine design process and can also be used when no relevant type C standards are available.
In production plants, machine tools are generally operated by skilled and well qualified personnel, in order to assure high productivity and full exploitation of their capacity. Where such machines are used in other areas, for example for the production of false teeth in dental laboratories, the operators are however only semi-skilled, and are not as familiar with the machines. In such cases, the work is considerably more difficult when operation of the machine is complicated.
A simple menu control on the iPad, which is docked on the machine, is used for process control and monitoring of Datron dental milling machines. The programs are generated in the CAD/CAM system and sent directly to the machine. They appear there in the form of simple entries in a job list, and can be selected and launched directly by the user. The control system also shows which materials and tools are required for the task; this knowledge is not therefore required of the operator.
A further advantage is that once the program has been launched, the iPad can be undocked from the machine and used via WLAN as an external monitoring device. The operator can therefore call up the status of the machine, which job is currently running, and any faults that may have occurred without having to be at the machine. This means fewer interruptions, greater flexibility, and lower mental stress for the staff of a dental laboratory.
Chip-forming machining of metal and ceramic parts usually results in worker exposure to substances. Where cooling is required during the machining of metals, cooling lubricants are used. During retrieval of the machined parts from the machine, the worker often comes into direct contact with these substances. In the longer term, this can lead to irritation and diseases of the skin. Where ceramics are machined dry, fine dusts are produced that can also be unpleasant or harmful when they come into contact with the skin or are inhaled.
The raw material for the parts machined by the Datron D5 dental milling machines takes the form of blanks. These standardized discs are made of the desired material and fit directly into the automated clamping device on the machine. The workpieces do not therefore have to be clamped manually in the machine. The blanks are changed by a system that retrieves them automatically from a store within the machine. Following machining, the machine deposits the workpieces in an aperture in the machine housing from where the worker can retrieve them directly. New blanks are placed in the same aperture. This enables the machine to be used for longer periods without the safety door to the interior of the machine having to be opened. The worker is protected against exposure to hazardous liquids and dusts. The arrangement also makes setup fast and straightforward and obviates the need for it to be performed directly inside the machine with adoption of an unfavourable posture (see also EN 1005-4).