Fundamental investigations on the hole accuracy and surface quality when single-lip deep-hole drilling of thermoplastic resin by adjusting the tool shape

• Applicant: Professor Dr.-Ing. Dirk Biermann
• Subject Area: Metal-Cutting and Abrasive Manufacturing Engineering
• Term: from 2013 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 242342331

Plastics offer a variety of design options. Hence many applications result for this class of materials in industrial use. By the development of high-performance plastics other lightweight materials such as aluminum or magnesium are increasingly substituted. For the production of a large number of parts and components made of plastics, injection molding and extrusion processes are often used. In contrast, precision components available in limited quantities, or with a highly complex geometry, are made by machining processes.Challenges for the machining of plastics are the resulting process temperatures and the tendency of some plastics to absorb water. For some machining processes this results in a problem. This applies especially to the manufacturing process drilling, in which the induced heat and the chips have to be removed from the hole in order to ensure a safe process. For components requiring a hole with a high length to diameter ratio (l/D-ratio), it results in high process times, because many process interrupts are necessary to remove the chips and low cutting data are used to maintain the induced heat as low as possible.For metal components with holes that require a large l/D-ratio different deep-hole drilling processes are used. While deep-hole drilling is intensively investigated concerning the machining of metals, this is not the case in terms of machining of plastics. Therefore one goal of this research is to investigate if the known advantages of the deep-hole drilling of metals can be applied to the deep-hole drilling of plastics. Using the methods of statistical experimental design the single-lip deep-hole drilling process will be investigated for different thermoplastic resins with respect to the hole quality and its correlation with the cutting data. Based on a simulation it is planned to develop a tool shape which allows small processing times while ensuring a high hole quality. For this purpose, different models based on the method of Design and Analysis of Computer Experiments (DACE) will be created which are then combined in a single simulation. To comprise a broad spectrum of different thermoplastic resins partially crystalline and amorphous thermoplastic resins are investigated.

• DFG Programme: Research Grants