Abstract: Within the actual context dominated by a strong need to improve cost and competitiveness, manufacturing companies are looking into the options to increase operational efficiency to which the equipment effectiveness is a key driver. One of the most common indicators for the equipment performance measurement within manufacturing environment is OEE (Overall Equipment Effectiveness), this being broadly used within various industries. Since it was introduced, it was acknowledged that by setting up an OEE based performance measurement, the companies can quantify better the performance and by its structured approach can run more focused diagnosis and consequently can look into exact areas of improvement. While various methods are used to calculate the equipment efficiency, the loss analysis still stays at the traditional technical level. But the current transition to the Industry 4.0, which is increasingly embraced by the companies, is showing a tremendous Data usage and impact into the overall performance measurement. The Quality of Data may influence both system performance and, equally, the loss analysis and decision making. Starting by using the classic Nakajima model for OEE calculation and loss analysis applied within a case study, the authors extended the loss analysis beyond the traditional process and technical aspects to cover as well the data potential impact into the OEE losses. This is a starting point for further detailed study to develop loss analysis models having the Data as a starting point and to understand how decision making is influenced.

Key words: Equipment Efficiency, Decision Making, Data, Loss Analysis, Performance Measurement.

pp. 157-164 View full text

Particularities of implementing Industry 4.0 concept in the automotive industry

Florin ENACHE^1,*, Stefan VELICU²

¹⁾ PhD Student, Doctoral School of Industrial Engineering and Robotics, University "Politehnica" of Bucharest, Romania

²⁾ Prof., PhD, Robots and Manufacturing Systems Department, University "Politehnica" of Bucharest, Romania

Abstract: The paper presents the new stage to be carried out by the current industry, in which technology has an important role and all the advantages brought by it, the optimization of the production processes and the real-time surveillance through the Internet connection. The principles and stages of implementation of the new concept Industry 4.0 (smartfactory) are presented, which incorporate intelligent machines, development applications and production facilities, capable of ensuring the exchange of information between them, autonomously and to control the final product, maintenance. predictive independently. This new stage of the industry represents the "fascination" of the moment, because it is predicted before being implemented, ensuring an increase in the efficiency in the industry and the development of new business models. Industry 4.0 involves the development of independent business activities, managing, supplying, manufacturing autonomously, creating a virtual copy, identical to the reality, managed by Cyber-Physical Systems (CPS), human personnel intervening only in critical situations, putting themselves emphasis on continuous increase of efficiency and productivity, permanent integration of information technology and technological communication.

Key words: Industry4.0, CPS, SmartFactory, artificial intelligence, digitization.

pp. 165-177 View full text

Rethinking higher education qualification from Romanian technical field

Cristina Vasilica ICOCIU¹, Tiberiu Gabriel DOBRESCU^2,*, Cătălin Ionuț SILVESTRU³, Nicolae POSTĂVARU⁴

¹⁾ Lecturer, PhD, Economic Engineering Department, University "Politehnica" of Bucharest, Romania

²⁾ Prof., PhD, Robots and Manufacturing Systems Department, University "Politehnica" of Bucharest, Romania

³⁾ Assoc. Prof., PhD, Robots and Manufacturing Systems Department, University "Politehnica" of Bucharest, Romania

⁴⁾ Prof., PhD, Metal structures, management and graphics engineering Department, Technical University of Civil Engineering Bucharest, Romania

Abstract: Romanian technical higher education is now at a crossroads and must be reset, rethought, rearranged on new directions, on the one hand taking into account the international results obtained by the technical universities and on the other hand the new European requirements. The European single market requires the recognition of qualifications in order to comply with one of the requirements of the Accession Treaty: free market access for services and goods. This requires the Romanian education to adopt measures that translate into its reset, such as primarily: it requires the adoption of ISCED classification, it requires the adoption of skills/ abilities and knowledge from ESCO as well as the transition to learning outcomes as a result of the education process. At the same time, learning outcomes require common assessment and certification systems at the level of the technical system, together with the involvement of market representatives in the process of curriculum design as well as assessment and certification of learning outcomes. Therefore, it is a different kind of school than the one that has existed

for the past 25 years, that is one essentially student-centered and focused on efficiency.

Key words: learning outcomes ISCO, ESCO, skills, study programs, efficiency.

pp. 179-184 View full text

Unbalance analysis of high speed motor spindle

Claudiu BISU^1,*, George CONSTANTIN²

¹⁾ Assoc. Prof., PhD, Robots and Manufacturing Systems Department, University "Politehnica" of Bucharest, Bucharest, Romania

²⁾ Prof., PhD, Robots and Manufacturing Systems Department, University "Politehnica" of Bucharest, Bucharest, Romania

Abstract: The main spindle or the motor spindle is the key element of a machine tool and in the condition of high speed movement the dynamic behavior is absolute necessary to be stable. This paper highlights the need for control over the spindle unbalance along with the action needed to reduce it. The research proposes an experimental protocol to clarify differences that occur at high rotational speed. Even in the situation of a minor residual unbalance obtained at low spindle balancing or during the rig test, the appearance of critical speed is very probable. The paper proposes an experimental procedure based on two type of balancing, at the low speeds on the balancing machine and at high speed directly on the machine tool. The study provides also an analysis of the balancing appearance and the classification of the vibration level according to the ISO standard conditions.

Key words: machine-tool, motor spindle, unbalance, balancing, vibration.

pp. 185-190 View full text

Mechanical properties of thermoplastic polymers 3D printed in a low vacuum environment

Aurelian ZAPCIU^{1, *}, George CONSTANTIN²

¹⁾ Eng., PhD Student, Faculty of Industrial Engineering and Robotics, University “Politehnica” of Bucharest, Bucharest, Romania

²⁾ Prof. Dr. Eng., Industrial Engineering and Robotics Faculty, University “Politehnica” of Bucharest, Romania

Abstract: 3D Printing with high processing temperature polymers brings challenges due to the exposure of the printed part to ambient air convection leading to thermal stresses inside the part and improper interlayer adhesion. This results in parts that have inferior mechanical properties compared to other manufacturing methods. This paper presents a method of improving printability and mechanical properties of parts from high processing temperature polymers by eliminating or drastically reducing the impact of ambient air with the use of a low-vacuum printing chamber. Tests parts were printed in a specially-designed 3D printer with an enclosed, vacuum sealed printing chamber. The air inside the print chamber was evacuated before the printing process begins. Specimens made from polyetherimide (PEI - ULTEM 1010) showed a 14% increase in strength when printed in a low-vacuum environment, using the same process parameters, while specimens made from acrylonitrile styrene acrylate (ASA) did not show significant differences. Additionally, surface quality was investigated using atomic force microscopy showing the method did not produce significant changes in surface roughness. Neither did the thermal behavior of 3D printed parts investigated using differential scanning calorimetry. The results point to removal of the convective thermal transfer during the 3D printing process having an overall positive effect on mechanical properties.

Key words: 3D Printing, vacuum chamber, engineering plastics, FDM, polyetherimide.

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