Anders Kinnander

The productivity potential assessment method: Assessing and benchmarking the improvement potential in manufacturing systems at shop‐floor level

Purpose – The papers aim is to focus on the productivity potential assessment (PPA) method which has been developed to measure and assess the productivity potentials at shop‐floor level in Swedish manufacturing industry.Design/methodology/approach – A study was carried out in one day by two certified analysts using a highly standardised work process. The focus is on a selected bottleneck area of a factory. Measurement from the selected area is combined with a broad data collection to make an assessment of the potential for increasing the productivity in the factory. The results were fed back to the factory management orally on the same day and in a written report.Findings – The paper shows that the PPA method was not designed to be a research method. It is a practical method that is based on a systems perspective where as many factors affecting the productivity and productivity development are gathered in one day.Research limitations/implications – A consecutive article will present the result from the s...

An experimental investigation of temperature and machinability in turning of compacted graphite irons

The life and the performance of an insert in metal cutting are mainly dependent on the heat that is generated in the contact zones on the tool rake face with chips and on the flank face with the transient and machined surfaces. According to tool life standard, the wear on the flank face is usually taken as a decision for tool life. This occurs because of contact stresses, temperature and friction between tool workpiece contacts. Hence, knowledge of temperature on the flank face becomes important. The temperature on the flank face has been measured in this work for different CGI materials having different microstructure and physical properties in a turning operation. It has been seen that there is no significant difference of flank temperature, while machining different CGI materials having hardness from (140 to 236 HBW). For temperature measurement, special inserts integrated with gold-platinum thermocouple on the flank face were used. It has been noticed that the materials having 31% resultant cutting force difference and six to eight times tool life difference have almost same temperature on the flank face measured at different distances from the edge line of the insert.

Machinability evaluation of pre-hardened plastic mould steels

There are multiple demands placed upon plastic mould steels, depending on the application they will have. Among these requirements, machinability has generally a great economic importance in mould steels and in pre-hardened mould steels in particular. The machining cost can exceed more than half of the cost of a mould. Nevertheless, to avoid subsequent heat treatment, distortion and dimensional inaccuracy, there has been the tendency to use even higher hardness in the pre-hardened mould steels, a hardness range of 38-40 HRC instead of 30-32 HRC. In this work, machinability of some of the most popular grades of pre-hardened plastic mould steel at 38-40 HRC is compared in two milling and two drilling operations. The materials have shown very different properties in different machining operations. This, beside the high requirements upon the plastic mould steels, such as polishability, hardness, impact toughness etc. makes it very complicated to improve these types of steels to be superior in all mould applications.

An Experimental Investigation of the Influence of Cutting Edge Geometry on the Machinability of Compacted Graphite Iron

Compacted graphite iron (CGI) is considered as the potential replacement of flake graphite iron (FGI) for the manufacturing of new generation high power diesel engines. Use of CGI, that have higher strength and stiffness as compared to FGI, allows engine to perform at higher peak pressure with higher fuel efficiency and lower emission rate. However, not only for its potential, CGI is of an area of interest in metal cutting research because of its poor machinability as compared to that of FGI. The higher strength of CGI causes a faster tool wear rate in continuous machining operation even in low cutting speed as compared to that for FGI. This study investigated the influence of cutting edge geometry at different cutting parameters on the machinability of CGI in terms of tool life, cutting force and surface roughness and integrity in internal turning operation under wet condition. It has been seen that the cutting edge radius has significant effect on tool life and cutting forces. The results can be used to select optimum cutting tool geometry for continuous machining of CGI.