© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

CONTINUOUS EVALUATION OF MACHINING ACCURACY BY IN-MACHINE MEASUREMENTS

Jaromir ZELENY¹, Michal JANDA¹, Martin NOVAK^1
1RCMT, Research Center of Manufacturing Technology, CVUT Prague

Abstract

The paper describes a relatively new area of measuring methods for workpieces machined on numerically controlled machine tools. The area is called "in-machine measurement" and means measuring of workpieces still placed in the working space of the NC machine immediately after the NC machining operation. Measuring is performed by a touch probe inserted into the machine spindle and the movements of the probe are programmed to touch the workpiece in pre-selected points of machined surface. This makes it possible to compare the measured points with corresponding points of the CAD model and thus evaluate deviations in the normal direction between the ideal and real surfaces. In the RCMT - Research Center of Manufacturing Technology in Prague, the research of in-machine measurement methods is performed on two installed high-precision milling machines equipped with linear motors. The task is solved as a part of the HARDPRECISION European project with the aim to verify possibilities in replacing application of conventional coordinate measuring machines by continuous or periodic in-machine measurements on production machine tools.

Author Keywords :

machining, accuracy, measuring

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

DEVELOPMENT OF A NEW INTEGRATED MACHINING SYSTEM ~ IMPROVEMENT OF SURFACE CHARACTERISTICS ON METALLIC BIOMATERIALS WITH A NEW ELECTRICAL GRINDING SYSTEM ~

Masayoshi MIZUTANI¹, Kazutoshi KATAHIRA¹, Hitoshi OHMORI¹, Jun KOMOTORI^2
1RIKEN, The Institute of Physical and Chemical Research
²Department of Mechanical Engineering, KEIO University

Abstract

Bio-implants, such as artificial joints, require high efficiency and precision processing because they are intricate forms. Especially, in the case of the stem of artificial joints, it is necessary to produce in the form united with the patient. In addition, the downsizing of bio-implant materials has been progressing, thus requiring ultra-precision processing techniques. Biomaterials also require enhanced chemical stability and mechanical properties, which are dependent on the quality and thickness of the oxide layer on their surface. Therefore, if we can form a thick and stable oxide layer during machining process, it is very effective in improving the surface properties. This will also help us to skip other surface treatment and allow for significant saving in energy. In this study, to discuss the applicability of an ELID (Electrolytic In-process Dressing) grinding for finishing process of biomaterials, the ground surfaces were analyzed. Finished surfaces produced by a new electrical grinding system showed higher corrosion resistance and tribological properties as compared to those of the polished surfaces. It is believed that this new system improves corrosion resistance and tribological properties by creating a thick oxide layer with a diffused oxygen and carbon element.

Author Keywords :

surface modification, biomaterials, high quality surface, ELID grinding

Author Keywords :

reconfigurable machine tool machine tool design machining features, process planning

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

GEOMETRICAL AND KINEMATICAL DESIGN OF RECONFIGURABLE MACHINE

Hasan ALADAD¹, Alain D'QCUNTO¹, Patrick MARTIN^1
1Laboratoire de Génie Industriel et de Production Mécanique (LGIPM)-ENSAM 4 rue Augustin Fresnel 57078 METZ-cedex 3- tél: (33) 03 87 37 54 65 mail : hasan.aladad@metz.ensam.fr

Abstract

Reconfigurable Machine Tool (RMT) is the critical issue to realize both the flexibility and productivity of manufacturing systems and to satisfy the mass-customization production. The purpose of this paper is to present reconfigurable machine tool design process. Specifically, geometrical and kinematical architectures design of RMT starting from a set of process data assigned to a given part family. The geometrical architecture specifies required tool approach directions of spindle of RMT to achieve a task under the concept of accessibility and fusion. Whereas, the kinematical architecture enables to determine all required motions (motion, range of axes) in order to realize the task. We used the dual vector with a view to generate the kinematical architecture.

Author Keywords :

reconfigurable machine tool, machine tool design, machining features, process planning

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

ONLINE OPTIMIZATION OF VIBRATION MANUFACTURING SYSTEM

Jirí VONDRICH¹, Evzen THONDEL^1
1Department of Mechanics and Materials Science, Faculty of Electrical Engineering, Czech Technical University in Prague, Technicka 2, 166 27 Prague 6, Czech Republic, vondrich@fel.cvut.cz

Abstract

The aim of the paper is to acquaint the reader with the design of the incorporated absorber to the vibration manufacturing system, which makes the reduction of the vibration of the manufacturing system to a minimum possible. Vibration in a manufacturing system has two effects. First, the very high peak accelerations can mean that the effective weight of the vibration manufacturing system increases several-fold, and this may cause its destruction. Secondly, people near the manufacturing system feel these accelerations, which can be uncomfortable or even dangerous. A vibration absorber is used to protect the manufacturing system from steady-state harmonic disturbance. By attaching the absorber to the manufacturing system, which is modelled as a SDOF system, the new system becomes a two DOF system. Depending on the driving frequency of the original system, the absorber needs to be carefully tuned, that is, to choose adequate values of absorber mass and stiffness, so that motion of the original mass is a minimum.

Author Keywords :

vibration, manufacturing system, LQR control, Matlab, Simulink

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

CRITERIA OF BALL SCREWS SELECTION FOR CNC MACHINES

Jerzy Z. SOBOLEWSKI^1
1Institute of Machine Design Fundamentals, Warsaw University of Technology, jso@simr.pw.edu.pl

Abstract

Ball screws are used as elements of feed systems in CNC machine tools working with constantly higher cutting speed. Work concerns designing ball screws with regard of dynamic conditions of feed system. The method of calculation depends on the positioning system existing in the machine tool. There are two positioning system possible - indirect (semi-closed loop) and direct (closed loop). For the indirect system, the main criterion of the ball screws of choice is a suitable drive rigidity and for direct positioning system the diameter of the screw is determined by the axial resonance of the table-screw ensemble. To improve the positioning accuracy it requires a good balance in axial rigidities of composing parts of feed system. The geometric and dimensional errors must be also considered in calculation process especially in the hertzian deflection of ball/balltrack area. A coefficient known a the geometric correction factor was introduced in order to estimate the influence of machining errors on the rigidity lowering. This coefficient was compared to the correction factor of accuracy applied in ISO standard for estimating ball screws rigidity.

Author Keywords :

ball screws feed systems, design parameters

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

DEVELOPMENT OF THE MODULE FOR REAL-TIME VERIFICATION OF NC MACHINING PROGRAM

Zoran MILOJEVIC¹, Slobodan NAVALUSIC¹, Milan ZELJKOVIC^1
1Institute for Production Engineering, Faculty of Technical Sciences, V. Perica Valtera 2, 21000 Novi Sad, Serbia

Abstract

In the simulation and verification of the NC machining programs most often approaches are: exact and approximate approach. For real-time NC machining program verification, only approximate approaches are suitable, by the reason of simulation cost O(N)( simulation time grows linearly with the number of tool movements). For the real-time purpose simulation it is important that simulation is not view-depended and animation should be smooth by 25 frames per second. In this paper a developed module for approximate approach verification of generated NC machine program for three axis milling is presented, based on dexels. Workpiece and tool are approximated by dexels, which are connected by triangular mesh. Depends on the computer hardware, workpiece and tool resolution may vary. This approach enables that tool and workpiece could be arbitrary shape. System is developed by use of 3D graphics library OpenGL which also, enables a stereo viewing, and that fact could be important in virtual reality era today. Machined workpiece could be transferred as a polygonal mesh in the some of commercial CAD systems for afterward analysis.

Author Keywords :

3-axis milling, dexel structure, NC machining program verification

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

QUANTIFICATION OF MACHINING AND FIXTURE ERRORS: 3D METHOD AND APPLICATION

Stephane TICHADOU¹, Olivier LE GOFF¹, Jean-Yves HASCOET^1
1IRCCyN Institut de Recherche en Communication et Cybernetique de Nantes, Unite mixte CNRS n°6597, 1 rue de la Noe, 44321 Nantes Cedex 3 - France

Abstract

In the context of manufacturing precision, our interest is the 3D quantification of the manufacturing errors. This paper presents a measuring method of the manufacturing deviations. We sort the errors from machining operation and the errors of workpiece location. First, we present our method through an 1D model. We demonstrate with a statistical simulation that it is possible to identify separately these two kinds of manufacturing variations. To do so, we propose a double measurement of the workpiece. The first consists to probe the machining surfaces when the workpiece is always staying on the part-holder. The second consists to probe the machining and location surfaces of the workpiece (at the end of the set-up) with a coordinate measuring machine. Our current model for geometrical manufacturing simulation describes the geometrical errors of part surfaces with the small displacement torsor concept. The results of our method are torsor components variations. We have deployed our method through an industrial application. We compare two different kinds of workpiece fixture and we quantify 3D machining deviations. Thus we can select the best process plan which satisfies the required geometrical manufacturing conditions.

Author Keywords :

manufacturing errors, machining and fixture variations and fixture, component distribution of small displacement torsor, industrial milling application.

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

ERROR TYPES AT PARALLEL KINEMATICS MACHINE TOOLS

Zoran PANDILOV¹, Valentina GECEVSKA^1
1University "Sv. Kiril i Metodij"-Skopje, Faculty of Mechanical Engineering, Karpos II b.b., P.O.Box 464, MK-1000, Skopje, Republic of MACEDONIA Tel.: 389 2 3099 259 Fax: 389 2 3099 298 E-mail: panzo@mf.edu.mk

Abstract

Theoretically parallel kinematics machine tools should be very accurate and rigid due to their closed loop structure and no error accumulation characteristics. Unfortunately, these theoretical presumptions have not been confirmed in practice. This paper gives a survey of the types of errors which significantly decrees the expected accuracy of the parallel kinematics machine tools.

Author Keywords :

parallel kinematics, machine tools, errors, accuracy

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

A CONTRIBUTION TO WORKSPACE ANALYSIS OF MACHINE TOOLS BASED ON PARALLEL MECHANISM

Slobodan TABAKOVIC¹, Milan ZELJKOVIC¹, Ratko GATALO^1
1 Institute for Production Engineering, Faculty of Technical Sciences, V. Perica Valtera 2, 21000 Novi Sad, R. Serbia

Abstract

Development and improvement of the theory of parallel mechanisms has recently resulted in its broader application for scientific and research purposes. Within the research carried out at the Faculty of Technical Sciences, aimed at classification of the work areas of parallel-mechanism- based machine tools, the analysis of the three typical types of mechanisms, including tripod, triglide and orthoglide, was conducted. This paper presents a part of this classification results referring to the triglide mechanism.

Author Keywords :

parallel mechanism, machine tool, workspace analysis

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

COMPLEX MODEL OF TWO-AXIS TELESCOPIC COVERS: INTRODUCTION AND SEALING WIPER BEHAVIOUR

Jan HUDEC¹, Petr KOLAR^1
1Research Center for Manufacturing Technology, CTU in Prague, Horska 3, 128 00 Prague 2, Czech Republic

Abstract

Nowadays design of machine-tool telescopic covers is usually based on empiric knowledge only. A complex model of cover dimensions, statics and dynamics presented in this paper will make the design process faster and more accurate. Results of this model can be used for correction of axes drive control. Polyurethane sealing wiper is one of crucial parts of telescopic covers that protect axes of machine tools. Wiper must be preloaded by cover plate to work properly. This preload and a friction resistance of wiper however strain all parts of cover and drive. Data obtained by measurement of wiper resistance presented in this paper are essential part of component properties library used as an input of submodel predicting wiper behaviour. This submodel represents a fraction of the whole complex model.

Author Keywords :

two-axis cover, model of covers,sealing wiper

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

APPROACH FOR SIMULATING BALL BEARING SCREWS IN THERMAL FINITE ELEMENT SIMULATION

Sven GLEICH^1
1Institute of Machine Tools and Production Processes, Prof. R. Neugebauer, University of Technology Chemnitz, Germany

Abstract

When simulating the thermal behaviour of a machine tool and its components the everlasting question arises: how to simulate the motion of the structure? Beside the approach of continuously re-meshing it is particularly interesting to use a static mesh at a conceptual stage of the design phase. That gives the engineer a fast response time of the model if he tries to play around with model parameters. The contribution to the workshop will describe an approach which uses finite element models with little nodes and elements. It will be shown how to connect the appropriate parts in the model, which parameters are used for the coupling and how to connect them to get a motion-like thermal load. Furthermore it will be described how to implement this model into a complex model of a machine tool. The used FE software is Ansys, but the general approach can be transferred to any FE software.

Author Keywords :

thermal FEA simulation, machine tools, ball bearing screw

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

COMPENSATION OF THERMAL DISPLACEMENTS OF HIGH-SPEED PRECISION MACHINE TOOLS

Jerzy JEDRZEJEWSKI¹, Wojciech MODRZYCKI^1
1 Institute of Production Engineering and Automation, WrocLlaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, tel./fax: +48 71 3202703, POLAND

Abstract

In order to manufacture high quality products the accuracy of machine tools must be increased. The accuracy of high-speed precision machine tools is mainly determined by errors caused by thermal displacements. Hence it is necessary to compensate thermal errors in real time, using a volumetric error model. The paper discusses problems relating to the modelling and compensation of thermal errors, using as an example the high-speed machining centre. Attention is drawn to the conditions in which investigations aimed at identifying and preparing input data for a volumetric error model should be conducted. The accuracy of thermal error reproduction and the effectiveness of real-time compensation of the high-speed machining centre's thermal errors are analyzed.

Author Keywords :

machine tool, thermal displacemen, compensation

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

INLUENCE OF TOOLING SYSTEM ON CUTTING EFFICIENCY

Petr KOLAR^1
1 Research Center for Manufacturing Technology, CTU in Prague, Horska 3, 128 00 Prague 2, Czech Republic

Abstract

The total cutting efficiency is ratio average value of the specific cutting powers to spindle drive power. can not affect the dynamics of the spindle, but he can choose suitable tooling system. So the user can tune dynamical properties of the whole spindle-tool holder - tool system because the tooling system has significant influence to the machining efficiency. In comparison of different tooling systems and their influence to the cutting power is presented. The general recommendations for choice of tooling system of high performance cutting are given in the paper.

Author Keywords :

cutting efficiency dynamical compliance tooling systems

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

A STUDY OF CUTTER PATH IN HIGH SPEED ROUGH MILLING OF POCKETS. PART I: MODELLING AND PERFORMANCE EVALUATION

Michelangelo GIULIANI¹, Michele MONNO², Gaetano Massimo PITTALA^2
1Laboratorio MUSP, Le Mose Strada Statale 10, 29100, Piacenza, Italy
²Dipartimento di Meccanica, Politecnico di Milano, Via Bonardi 9, 20133, Milan, Italy

Abstract

Considering large aeronautical parts, such as wing ribs, a volume up to 90-95% of the initial weight is removed. Prticularly pocket milling takes 60-70% of the total cycle time, so this operation plays an important role in the cost definition of the final product. Since typical materials in aircraft frames are aluminium alloys. High Speed Machining technology is convenient and more frequence used, also for rough operation. Using modern production systems cutting velocity and feedrate are relatively high also in rough machining. Main features of linear trajectory and cubic spline trajectory have been numerically evaluated in part I of this paper. In the second part tool paths have been experimental tested in terms of machining time considering high speed rough machining of pockets; a comparison between linear interppolation and cubic spline has been performed using CNC systems and an open architecture revolute robot.

Author Keywords :

high speed rough milling, pockets, spline interpolation, experimental evaluation

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

A STUDY OF CUTTER PATH IN HIGH SPEED ROUGH MILLING OF POCKETS. PART I: MODELLING AND PERFORMANCE EVALUATION

Luca GIORLEO¹, Michelangelo GIULIANI², Gaetano Massimo PITTALA¹, Massimo RUBERTO^3
1Dipartimento di Meccanica, Politecnico di Milano, Via Bonardi 9, 20133, Milan, Italy
²Laboratorio MUSP, Strada Statale 10 Localita Le Mose, 29100 Piacenza, Italy
³Dipartimento di Ingegneria dei Materiali e della Produzione, Facolta di Ingegneria, Universita degli Studi di Napoli" Federico II", P.le Tecchio, 80, 80125 Nalpes, Italy

Abstract

Large aeronautical parts, such as wing ribs, involve a volume of metal removed up to 90-95 % of initial weight, particularly pocket milling takes 60-70% of the total cycle time, so this operation plays an important role in the cost definition of the final product. Since typical materials in aircraft frames are aluminium alloys, High Speed Machining technology is convenient and more frequently used, also for rough operation. Using modern production system cutting velocity and feedrate are relatively high also in rough machining. It is important to determine cutter path and position vs time law in order to allow the lowest machining time and to control machine dynamic conditions. In this paper linear trajectory and cubic spline trajectory are compared in terms of execution time during high speed rough machining of pockets; in this part the comparison is numerical. The results indicate time saving using spline interpolation and the influence of feedrate and acceleration profile about above cutter paths. This is important information to select best cut condition and machining performance.

Author Keywords :

high speed, rough milling, cutter path, pockets, spline interpolation

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

ABOUT THE TOOL'S MOTION IN THE POLYGONAL HOLES DRILLING APPLYING CENTRODES

Miodrag ZLOKOLICA¹, Maja CAVIC¹, Milan KOSTIC^1
1University of Novi Sad, Faculty of Technical Sciences, P.O. Box 55, Trg D. Obradovica 6, 21121 Novi Sad, Serbia

Abstract

The polygonal holes can be made in many different ways but using the rotating tool in drilling process is one of the easier and most efficient ways for doing it. The aim of this paper is, for the given constant angular velocity, to determinate motion, and velocity of the tool's blade used for polygonal hole production in the manufacturing process as mechatronics system. The given task will be solved using the equivalent mechanism and applying centrodes theory. Euler- Savary equations with matrix vector notation will be used for defining the velocity of tool's blade as well as geometry of polygonal contour.

Author Keywords :

kinematics, polygonal holes, manufacturing process, cutting velocity

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

WIRE ELECTRICAL DISCHARGE MACHINABILITY OF WC-CO CEMENTED CARBIDES

Stanisław ZABORSKI¹, Dariusz POROS¹, Adam SUDZIK^1
1Wroclaw University of Technology Institute of Production Engineering and Automation ul. Lukasiewicza 5, 50-371 Wroclaw, e-mail: stanislaw.zaborski@pwr.edu.pl, POLAND

Abstract

Cemented carbides are widely used in industry as the structural components or wear-resistant parts (including tools and dies) and other applications where the demand for highperformance materials is essential. About 60% of the punches, used within dies for the production of high quality sheet metal parts, are made of WC-Co. These materials are machined either by WEDM or electrochemical grinding or grinding. WC-Co cemented carbides characterize good wear and corrosion resistance but are difficult-to-machine by conventional methods. WEDM of WC-Co can be automated and enables machining of complex shapes. The influence of the material properties and the composition (cobalt content) of HF6 and G20 cemented carbides on the WEDM technological effects is studied in this paper. The research was realized on the electrical discharge machine Sodick AQ 300 l which provides no wear compared to balls crews, no vibrations and perfect positioning through linear glass scales.

Author Keywords :

composition of sintered carbides, cemented carbides, WEDM

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

INNOVATIVE APPROACH TO PROBING SOFTWARE FOR ON-MACHINE INSPECTION

Lukasz SLAZAK1^1
1Renishaw Sp. z o.o., Szyszkowa 34, 02-285 Warsaw POLAND, tel. 0048225771185, e-mail: lukasz.slazak@renishaw.com

Abstract

Nowadays inspection systems enabling probing on machine tools are getting a popular option for three, four and five axis machining centres. Such systems are set of two parts - hardware (inspection probe) and software. Paper presents innovative approach to inspection software (including toolsetting applications) creation depending on machine type and application. Last but not least is the issue of software influence on productivity of manufacturing process. Due to different user demands and expectations following software levels were designed and introduced by Renishaw: OEM level software and End user (EU) level software. OEM level software is aimed at machine tool manufacturers - prepared for full integration with machine tool controller. EU level software is suitable for retrofits and custom applications - designed in more flexible way, easy to adjust for complex probing tasks. Paper contains comparison of these two groups of software including examples from aerospace industry. Additionally, simple user guide for choosing probing software for certain application was proposed.

Author Keywords :

inspection software, machine tool, probes

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

DIAGNOSTICS OF MACHINING AND ASSEMBLY SYSTEMS BY NETWORKED MOTES

Jurgo PREDEN¹, Martins SARKANS¹, Tauno OTTO^2
1Tallinn University of Technology, Dep.of Comp.Contr., Ehitajate tee 5, 19086 Tallinn, Estonia, jurgo.preden@ttu.ee
²Tallinn University of Technology, Dep.of Machinery, Ehitajate tee 5, 19086 Tallinn, Estonia, msarkans@staff.ttu.ee

Abstract

Distributed computing solutions based on miniature computing devices called "smart dust" were introduced in the beginning of the current century. Prototype applications of wireless sensor networks, which form a subset of smart dust solutions, have been developed in military, meteorological, agricultural and office domains. As shown in the current research this new technology has great potential in manufacturing systems, enabling the creation of independent monitoring layer for measurement essential parameters like temperature, humidity, vibrations, movement, noise. The sensors are integrated into small sized boards and equipped with small sized accumulators; because of autonomous power supply andwireless communication interface the deployment of these systems is simple, relatively cheap and fast - integration with existing equipment is possible with little effort. For industrial applications the size of the sensor board is not critical, and therefore it enables to increase the size of energizer allowing maintenance free operation. The modularised test network model was built at Tallinn University of Technology for adding information input from flexible manufacturing system consisting of two robots, CNC mill, two CMM and conveyer system. The system is monitored by eight motes. Data from sensor boards is analyzed and saved in database.

Author Keywords :

diagnostics, FMS, smart dust, modularisation, wireless sensor networks

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

PRODUCTION AND QUALITY MANAGEMENT OF KNITTING PRODUCTS

Robert ULEWICZ^1
1 PhD, Department of Engineering Production, Management Faculty, Czestochowa University of Technology

Abstract

In article were presented results of researches carried out in knitting company, which is specializing in lady's sweaters production. Company's organizational structure is characteristic for polish family enterprises. In order to establish incompatibilities level of produced products there was carried out analysis based on usage of Ishikawa and Pareto-Lorenz diagram in two researched periods. Results of the above analysis were defined as starting point for elaborating the proposal of quality level improvement. For description and selection of the most optimal quality improvement proposals there was used relations diagram. There was also proposed implementation at work places 5S practices, organizational structure reorganization and also change of the choice and qualification way of raw materials' deliverers. In this purpose there was used PDPC diagram for raw materials quality improvement.

Author Keywords :

quality, incompatibility, knit goods Pareto - Lorenz, Ishikawa

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

METHODS FOR ENHANCING PRODUCTIVITY AND WORK EFFICIENCY IN THE WORKSHOP

Juri RIIVES¹, Tauno OTTO², Kaia LOUN^3
1Federation of Estonian Engineering Industry, Mustamäe tee 4, 10621, Tallinn, Estonia, jyri@eestitalleks.ee
² Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn, Estonia, tauno@staff.ttu.ee
³J.R. Technoconsult, Kola 2b, 10918, Tallinn, Estonia, kaia.loun@mail.ee

Abstract

The use of computer numerical controls (CNC) enables to the transfer the set-up function from the machinists to computer programmers and manufacturing engineers. The workshop productivity increasingly depends on skills and knowledge of whole workshop team. Different equipment and competencies are needed depending on complexity of production. The humans' impact on productivity and the methods for enhancing the productivity and efficiency of work in the machinery workshop environment are described in this paper. The data covering 75 Estonian metalworking and machinery companies has been analyzed. A novel expert tool is introduced, where during the evaluation guess values are assigned onto machinery, products, and staff members of the workshop, reflecting existing and needed levels of competence and machinery, thus helping further process planning.

Author Keywords :

monitoring, human resource management, expert tool, process planning, productivity, eManufacturing

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

IDSS AS A TOOL FOR PROJECT MANAGEMENT IN A COLLABORATIVE NETWORK OF SME-S

Sergei KRAMARENKO¹, Eduard SHEVTSHENKO², Tatyana KARAULOVA^2
1AS BLRT Grupp, Tallinn, Estonia, s.kramarenko@bsr.ee
²Tallinn Technical University, Ehitajate tee 5, 19086, Tallinn, Estonia, tatjana.karaulova@ttu.ee

Abstract

Rapid advances in technologies such as networks, database analysis techniques and high speed data processing helped the growing importance of organizational decision support systems. Integration of a various resources of information and knowledge for companies enhances their decision-making process in the framework of the real project. Development of this problem is offered in this paper. The Intelligent Decision Support system (IDSS) designed in this work helps a project manager in the decision support process during projects' management. IDSS is responsible for the information management and analysis. The output is the project portfolio selection proposals represented to the key users of the managing company.

Author Keywords :

intelligent decision support system, collaborative network of enterprises, project management

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

GCENTRAL HEATING BOILERS PRODUCTION AND QUALITY MANAGEMENT

Elżbieta KOPCIUSZEWSKA¹, Magdalena MAZUR^1
1University of Technology, Faculty of Management, Department of Production Engineering

Abstract

As the market is getting more and more competitive, maintaining high market position requires high product quality from companies. To the high quality of water central heating boilers contributes their workmanship, as well as saving during operation and low emission of chemical substances into the atmosphere. In this paper, presented are technical characteristic and manufacturing process of the LIBAL boilers. With the help of the Pareto_Lorenz diagram, the incompatibility causes structure in the LIBAL central heating boilers production process was established.

Author Keywords :

product quality, Pareto-Lorenz diagram manufacturing process

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

MACHINDETERMINANTS OF QUALITY OF PRINTING ON FOIL

Jacek SELEJDAK¹, Renata STASIAK - BETLEJEWSKA^1
1 Division of Production Engineering, Departament of Management, Częstochowa University of Technology

Abstract

One of the features which determines the sales volume of a product is a design of a product and, continuously, quality of overprint. There are several technologies of creation of overprint on various types of packages. The greatest part, particularly in the "foodstuffs- friendly" categories, belongs to the technology of flexography of overprint based on foil. A group of factors that influence the quality of overprint put on various types of foil has been determined in the work below. The data was based on the research led in a printing company. For the purpose of determination of the mentioned factors the analysis of the created discrepancies, according to the Pareto-Lorenz analysis and to the dependence diagram, has been made. The analysis proved that a human factor mostly influences the quality of overprint. Hence, some actions, which mainly aim to effect the procedures of activities, have been taken.

Author Keywords :

flexography, quality of overprint, discrepancies, the Pareto - Lorenzo analysis, a deendence diagram.

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

HIGH-PRESSURE ABRASIVE-WATER JET SURFACE TREATMENT MODEL BASED ON GENETIC ALGORITHM

Przemyslaw BORKOWSKI^1
1Koszalin University of Technology, Unconventional HydroJetting Technology Center

Abstract

The genetic algorithm, composed of 67 bits presented in the paper was developed to search for favorable process conditions of corrosion cleaning using the high-pressure abrasive-water jet. Due to application of specific numerical procedures the linear mono-parametric models of the surface machining process were developed. On the basis of process parameters stored in as the input data, the genetic algorithm enabled to determine the optimal process parameters for surface treatment of corroded steel plates implemented by the use of the high-pressure abrasive-water jet. The trained artificial neural network by making use of relations between such input parameters as: the water pressure, the water consumption, the feed, the distance of the sprinkler from the processed surface, the abrasive grain granularity, the abrasive consumption and the set output parameter i.e. the process productivity generated an adequate process model. This model consisting of a series of simple linear mathematic equations was subject to optimization by the use of the genetic algorithm. Due to that, the parameter values were generated ensuring the maximum process productivity by the use of abrasive-water jet that was the objective of the assumed numerical procedure.

Author Keywords :

surface machining, modeling, high-pressure abrasive water jet, genetic algorithm

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

MODELLING OF HIGH-PRESSURE SURFACE TREATMENT USING FINITE ELEMENT MODELLING METHOD

Przemyslaw BORKOWSKI¹, Adam SZPAKOWICZ^1
1Koszalin University of Technology, Unconventional HydroJetting Technology Center

Abstract

The method and results of surface modelling using computer algorithm based on ANSYS/LS-DYNA software are presented in the paper. Experimental results verifying numerical simulation (FEM) are presented too showing out satisfactory correlation between modelling and experimental practice.

Author Keywords :

high-pressure abrasive-water jet, numerical modelling

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

THE QUALITY OF SURFACE CUT AFTER HIGH-PRESSURE ABRASIVE-WATER CUTTING

JOzef BORKOWSKIsup>1, Marzena SUTOWSKA^1
1Koszalin University of Technology, Unconventional HydroJetting Technology Center

Abstrakt

Surface geometric structure (SGP) of materials cut with high-pressure water-abrasive jet is presented in the paper. There were classified all those structures next and experimental results of main cut parameters influence on SGP parameters are presented in. The structure of treatment traces depends on abradant kinetic energy distribution, therefore reliable SGP analysis needs measurements not only in the upper, but mostly in the lower cut area. Detailed statistical analysis of those experiments let to choose characteristic group of SGP parameters, adequate for cutting process. These are: Sa, Sq, SHTp, Sv, Smmr, Sz, Sci, Str and Ssc. They might be used for quantitative evaluation of SGP during high-pressure abrasive-water jet cutting.

Author Keywords :

high-pressure abrasive-water jet, materials cutting, surface structure

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

ABRASIVE GRAINS DISINTEGRATION AND REGENERATION USING HIGH-PRESSURE ABRASIVE-WATER JET

Przemyslaw BORKOWSKI¹, Jaroslaw PRAZMO^1
1Koszalin University of Technology, Unconventional HydroJetting Technology Center

Abstract

Problem of abrasives disintegration during separate stages of high-pressure water-abrasive jet creation are presented in the paper. Research methodology, experimental stand and its equipment, also work conditions are discussed in. Experimental results point out the size and characteristic forms of abrasive disintegration, giving possible to estimate such operation of abrasive recovery and regeneration. As it appears, intensity of abrasive grains disintegration, during the jet creation for surface treatment operation, is much lower than for cut operation. At the same time, the growth of the water pressure causes increased disintegration of abrasive material.

Author Keywords :

abrasive grains disintegration, abrasives regeneration, high-pressure abrasive-water jet, surface treatment

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

THE PROBLEM OF SURFACE TREATMENT USING HIGH-PRESSURE ABRASIVE-WATER JET

Przemyslaw BORKOWSKI^1
1Przemyslaw BORKOWSKI, Koszalin University of Technology, Unconventional HydroJetting Technology Center

Abstract

Presented paper adopts a theoretical approach to physical phenomena occurring during the creation of high-pressure abrasive-water jet making use of them as an erosive tool. The distribution of velocity and energy of grains in a jet and their influence on a workpiece were analyzed. The most essential interaction is caused of grains macro- and micro-stereometry and their spray direction. It concerns especially abrasive grains distributions in the abrasive-water jet cross-section. Research of all those phenomena and probable relations between them gives a basis for reasoning on dynamics of abrasive grains behavior under such conditions. Based on that it was possible to create a model of material erosion treated with high-pressure abrasive-water jet. The velocity of abrasive grains at the sprinkler outlet reaches values close to the flow velocity of water jet carrying them, however these grains at the contact zone with the workpiece reaches the velocity exceeding 100 m/s. Owing to this zone, the abrasive grains reveal very high kinetic energy close to 1x10^-3J. Under such cutting conditions the abrasives (#36) consumption reaches the level of the order of 25-30 g/s, which results in the increased flow rate of abrasive grains exceed the level of 70,000, reaching even 180,000 grains per second, whereas the surface erosion efficiency reaches the value (3-4)x10³mm²/s.

Author Keywords :

surface treatment, high-preassure abrasive-water jet, pressure distribution in water jet, erosion efficiency

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

THERMODYNAMICAL ASPECTS OF HIGH-PRESSURE WATER-ICE JET USED FOR SURFACE TREATMENT

Przemyslaw BORKOWSKI^1
1Przemyslaw BORKOWSKI, Koszalin University of Technology, Unconventional HydroJetting Technology Center

Abstract

Tests on a high-pressure water-ice jet are aimed at creation of a good water-jet tool used for surface cleaning. Ice particles admixed to this jet are impinge the surface with a high velocity and they should be characterized by erosiveness similar to abrasive grains. A method of jet formation consisting in acceleration of over-cooled dry ice particles by a high-pressure water jet is presented in this paper. Experimental results indicate conditions of high-pressure water-ice jet formation characterized by satisfactory abrasive and erosive properties

Author Keywords :

high-pressure water-ice jet, thermodynamical analyze, surface treatment

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

ABRASIVE GRAINS AND DRY-ICE PELLETS DISTRIBURTION IN HIGH-PRESSURE WATER JET USED FOR SURFACE TREATMENT

Przemyslaw BORKOWSKI^1
1Koszalin University of Technology, Unconventional HydroJetting Technology Center

Abstract

The paper presents properties and operational conditions for a high-pressure hydro-abrasive jet used for surface treatment. Methods of the assessment of abrasive grain distribution in such a high-pressure jet are discussed in. The present findings illustrate conditions necessary to form the abrasive-water jet with the most favorable distribution of abrasive grains conditioning the efficiency of surface treatment. Similar methodic was used for analogical examining realized for ice-water jet and hybrid (abrasive-water-ice) jet. The most favorable, flattened abrasive-grain and dry ice pellets distributions are obtained due to the application of the sprinkler with a four-outlet concentric nozzle. The increased number of water outlets in such the nozzle is usually conductive to the higher concentration of abrasive grains and ice particles in a jet and this solid particles rate, which involve the higher costs of surface treatment.

Author Keywords :

high-pressure hydro-abrasive jet, surface treatment grains distribution, dry-ice pellets distribution

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

HIGH-PRESSURE HYBRID JET STRUCTURE

Przemyslaw BORKOWSKI¹, Jozef BORKOWSKI^1
1Koszalin University of Technology, Unconventional HydroJetting Technology Center

Abstract

The high-pressure hybrid abrasive-ice water jet is a new technology that has grown in popularity lately. Such technology is based on a high-pressure water jet with addition of abrasives and dry-ice pellets CO₂. The experimental plant accompanied with suitable equipment is discussed in. Ice particles sublimation effect also structures of water pressure and abrasive grains distribution were researched. As it appears for the analysis the hybrid jet erosion efficiency, created by means of the sprinkler with the optimized 4 holes concentric nozzle, undergo a distinctive increase along with an increase in the water pressure and the sprinkler tube length. The lowest pressure occurs in internal layers of hybrid jets, whereas much higher pressure is characteristic for external layers with clear separated elementary jets which number is equal to the number of water holes arranged in sprinkler nozzles. All that influence on the abrasive grains distribution in the jet. Flow rate of abrasive grains (#36) during such high-pressure hybrid jet treatment reaching the range of 90,000÷150,000 grains per second while the ice pellets number is 70 times lower.

Author Keywords :

high-pressure hybrid abrasive-ice water jet structure, surface treatment

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

HIGH-PRESSURE HYBRID JET PROPERTIES IN THE ASPECT OF SURFACE TREATMENT

Przemyslaw BORKOWSKI¹ Walther MAIER^2
1Koszalin University of Technology, Unconventional HydroJetting Technology Center

Abstract

The hybrid abrasive-ice water jet treatment is a new technology based on a high-pressure abrasive-water jet with addition of dry-ice pellets CO₂. Theoretical basis, including kinetic energy of solid particles also with thermodynamical ice particles state during hybrid jet creation are presented in the paper. A problem of dry-ice pellets CO₂ sublimation effect in that hybrid jet, pressure and solid particles of abrasives and dry-ice distributions across the jet are also discussed in. It shows out that great volume of gas CO₂ generated rapidly in the contact area of dry-ice pellets with the work surface produces a very dynamic increase in the hammer water effect. It makes the cracks existing in the surface layer of the work material grow and disrupt. Moreover, very important factor that determines the high-pressure hybrid jet structure is abrasive and ice particles distribution. It results that the highest number of abrasive grains flows along the axis of an abrasive-water jet where the lowest total pressure prevails reaching the range of 90,000 - 150,000 grains per second. In practical conditions of a hybrid jet formation, the abrasive grains consumption is in the range of 100 kg/h and 150 kg/h of dry-ice particles respectively. In such conditions, for one ice grain erosion accompany of approximately 70 abrasive grains. Therefore all that proportions are important for treatment mechanism.

Author Keywords :

hybrid abrasive-ice-water jet, surface treatment, solid particles distributions, sublimation effect of CO₂

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

KINEMATICS OF THE ROTATION WATER JET IN THE ASPECT OF FLAT SURFACE TREATMENT EFFECTIVENESS

Jozef BORKOWSKI¹, Przemyslaw BORKOWSK¹, Zbigniew BUDNIAK^1
1Koszalin University of Technology, Unconventional HydroJetting Technology Center

Abstract

Analyses of surface treatment effectiveness using rotational multi-orifice nozzles are presented in the paper. Theoretical models of such jet traces distribution during flat surface treatment operations are presented too. Criteria of after-treatment traces distributions and their influence on rotational nozzles kinematics are also discussed in. Presented analytical results point out an influence of such most important kinematical parameters like: traces width, rotational velocity and feed rate of nozzles equipped with different orifices number, on such kind surface treatment efficiency. An increase in the rotational speed of the working head and the number of nozzles leads to an increase in the qualitative effectiveness of the surface treatment. The most effective method for increasing the qualitative effectiveness of the of travel of the working head, which causes the thickening of the post-machining marks.

Author Keywords :

high-pressure water jet, rotation water jet, surface treatment

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

THERMAL ASPECTS OF DIFFERENT STRUCTURES AND APPLICATIONS OF HIGH-PRESSURE WATER JETTING

Jozef BORKOWSKI¹, Przemyslaw BORKOWSKI¹, Artur SOKOŁOWSKI^1
1Koszalin University of Technology, Unconventional HydroJetting Technology Center

Abstract

Research temperature results using thermovision infrared camcorder are presented in the paper. Presented research methodology let to illustrate temperature distribution both inside the high-pressure jet and in the erosion zone showing real-time courses. Exemplary research results in the form of thermograms showing surface zone for high-pressure water, abrasive-water, ice-water and hybrid (abrasive-ice-water) jet are discussed in A comparison of treatment parameters influence on temperature creation in the erosion zone was also made. Experimental results prove that the highest temperature in the treatment zone (for p=30 MPa) is obtained using high-pressure abrasive-water jet heating up sample material up to 30^oC. Therefore, it is evident that high-pressure water jet erosion proceed in slightly increased temperature and that is way this kind of machining method can be defined as "cold machining".

Author Keywords :

thermo-vision examining, high-pressure water jet

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

NOISE LEVEL RESEARCH CARRIED OUT FOR DIFFERENT WATER-JET TREATMENT CONDITIONS

Jozef BORKOWSKI¹, Przemyslaw BORKOWSKI¹, Marzena SUTOWSKA^1
1Koszalin University of Technology, Unconventional HydroJetting Technology Center

Abstract

Noise level research results carried out for different work conditions of water-jet used for surface treatment and cutting are presented in the paper. Research were carried out for standard usage conditions of abrasive-water jetting as well as suspension abrasive-water jet created according to BorJet and MicroBorJet cutting machines and surface treatment generated in the sprinkler equipped with multi-outlet concentric nozzle and for different working heads made by Hammelmann. Influence of work parameters like water pressure and its rate, jet angle and its structure, abrasive material quantity and sort on noise level emission during different material treatment are also discussed in. Water jet abrasive-water jet, ice-water and hybrid jets created for different conditions were examined and compared in the aspect of their acoustic properties. Additionally, noise level was registered for underwater cutting and related to typical not immersed cut conditions.

Author Keywords :

noise level, high-pressure water jet, abrasive-water jet

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

THE CONCENTRIC SPRINKLER OPTIMIZATION USED FOR HIGH-PRESSURE ABRASIVE-WATER JET SURFACE CLEANING

Przemyslaw BORKOWSKI^1
1Koszalin University of Technology, Unconventional HydroJetting Technology Center

Abstract

Technical surface cleaning with high-pressure abrasive-water jet is becoming more prevailing in industry-wide applications. The most important in the high-pressure abrasive-water jet creation are the multioutlet concentric nozzle and the tube which are the main elements of the sprinkler. Therefore optimisation of water nozzle and tube construction in aspect of treatment efficiency maximisation has proved justified. For this purpose the wide theoretical analysis was carried out and 52 respective optimisation tests on different nozzle constructions and 16 different tube types as well, regarding 5 criteria that assure objective and complex evaluation of high-pressure abrasive-water jet functional quality. Consequently the optimal nozzle and tube construction solution were established that provide a significant increase in functional quality of the high-pressure abrasive-water jet.

Author Keywords :

high-pressure abrasive-water jet, water jet cleaning, multioutlet concentric nozzle, concentric sprinkler

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

MECHANISM OF ENAMEL DECOATING WITH HIGH-PRESSURE HYBRID JET

Przemysław BORKOWSKI^1
1Koszalin University of Technology, Unconventional HydroJetting Technology Center

Abstract

Specific aspects of enamel coated materials treatment with high-pressure hybrid jet are presented in the paper. Micro structural research points out bubble enamel structure causing that the most advantageous decoating process used for is high-pressure hybrid jet compounded of abrasive and dry ice pellets CO₂. Research results let to create enamel layer erosion model according to which perpendicular hitting of abrasive grains onto enamel surface causes more intensive erosion occurring in the form of cracks and gaps. Water is pressed then in those cracks as a result of relatively big dry ice pellets hits that violently sublimates partially. All that leads to intensive spalling and of the enamel material.

Author Keywords :

high-pressure hybrid jet, surface machining, enamel coating

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

OPTIMIZATION RESEARCHES OF ABRASIVE SUSPENSION JET GENERATED ACCORDING TO BORJET SYSTEM

Jozef BORKOWSKI¹, Przemyslaw BORKOWSKI^1
1Koszalin University of Technology, Unconventional HydroJetting Technology Center

Abstract

BorJet system that ensures effective creation of high-pressure suspension jet with hybrid admixtures and research methodology of such kind jetting are discussed in the paper. Optimization criteria and research results of hybrid jet erosion parameters influence on cutting effectiveness are presented too. All those research let to verify optimization criteria pointing out hazard in making mistakes taking into consideration only costs of abrasives consumption minimization omitting costs of hybrid admixtures, e. g. Super-Water emulsion or other kind polymer components. As it occurs, abradant costs incurred while cutting different work materials e. g. metal, non-metal and rocks are similar in character. An increase in water pressure is found to cause a decrease in the costs of materials, where their level depends on physical properties of work material. Whereas, a change in the sand quartz consumption allowing the abradant costs to be optimised, which optimum values mostly occur at the abradant consumption of the order of 60 70 g/s. The application of high-efficient synthetic abradant instead of silica sand causes all the material costs of suspension abrasive-water jet to be considerably higher. Therefore using of poly-fluidal and poly-hartenol occurs to be unprofitable. Therefore, the cutting processes of suspension water jet created according to BorJet's system are the most favourable if the abradant is admixed exclusively with silica sand #30.

Author Keywords :

high-pressure abrasive suspension water jet, minimizing costs of abrasive-water jet cutting

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

DEVELOPMENT OF MICRO-BOR-JET SYSTEM IN ASPECT OF SUSPENSION ABRASIVE-WATER JETS CREATION

Przemyslaw BORKOWSKI¹, Ryszard SOBCZAK^1
1Koszalin University of Technology, Unconventional HydroJetting Technology Center

Abstract

Original installation constructed to precise high-pressure abrasive suspension jet cutting, created according to MicroBorJet system is presented in the paper. Water pump of that system is a unit built of two push-pull synchronized pneumatic-hydraulic amplifiers. Basic parameters characterizing this system are: nozzle diameter (40-80 µm), working pressure (up to 100 MPa) and flow rate (3-8 dm³/h) of high-pressure abrasive suspension jet. Basis technological research let to determine the jet characterized with above parameters that enables precise cutting of different materials in a wide range. However it is necessary to develop adequate diamond nozzle hole geometry, characterized with satisfactory durability. Selection of proper abrasive, that is characterized with adequate density, fine-grained and dimensional homogeneity, also is a serious problem.

Author Keywords :

high-pressure abrasive-water jet, micro-cutting system, suspension abrasive-water jet

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

APPLICATION OF HIGH-PRESSURE WATER JETS TO INACCESSIBLE PIPELINE CLEANING

Przemyslaw BORKOWSKI¹, Jozef BORKOWSKI^1
1Koszalin University of Technology, Unconventional HydroJetting Technology Center

Abstract

After several dozen years of water pipeline usage, thick and hard pollutions layers in the form of stone are deposit inside. Such impurities are characterized with great hardness and adhesion to the substrate because the main compounds of the are iron, manganese, calcium and silicon. Effective cleaning of such pipeline is a real problem. Theoretical and experimental profile of developed hydro dynamic method of pipeline renovation using high-pressure water jet are presented too. Based on the whole work it should be mentioned here that this method of water pipe cleaning ensures high effectiveness of the process, since solid sediment is removed from 93÷96% of total inside area of a pipe. A significant rate of pipeline cleaning (of the order of 100÷120 m/h) at low consumption of process water (less than 6 m³/h) ensures low cost and short processing time. Moreover, this cleaning method is environmentally friendly because a working medium is clear water.

Author Keywords :

high-pressure water jet, pipe cleaning

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

HIGH-PRESSURE WATER JET USAGE TO ABYSSAL WELL RENOVATION

Jozef BORKOWSKI¹, Przemysław BORKOWSKI^1
1Koszalin University of Technology, Unconventional HydroJetting Technology Center

Abstract

The efficient methods of water-pipe line cleaning also filters and nearby zone of abyssal well after some decades of their operational use are presented in the paper. It consists in introducing inside the regenerated installation a special nozzle, where from high-pressure water jets of coherent structure and high power density are discharged. It results in breaking away and disintegration of sedimentary solids and their removal from the installation with process water or by additional rinsing. Design for nozzles and conditions of cleaning are selected depending on a type and technological properties and a diameter of the installation, but first of all on an amount and hardness of accreted incrustations and sediment deposited inside.

Author Keywords :

high-pressure water jet, renovation, abyssal well

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

WATER-JETTING TECHNOLOGY APPLICATION FOR SHIP'S SIDE SURFACE TREATMENT

Przemyslaw BORKOWSKI¹, Jozef BORKOWSKI^1
1Koszalin University of Technology, Unconventional HydroJetting Technology Center

Abstract

Cleaning the corroded ship's side using the high-pressure abrasive-water jet is a new technology in the shipbuilding industry that now undergoes the intensive development. The main trends in development are automation and mechanization of work and an increase in water jet pressure as well, while application of new technologies to Polish shipbuilding industry is limited for many reasons. Especially it applies to small shipyards where most of repair work to fish cutters is done manually. A highly efficient abrasive-water jet sprinkler designed for such cleaning operations along with thorough investigations are described in this paper.

Author Keywords :

high pressure water jet, surface treatment, ship's side removing

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

DEVELOPMENT OF HIGH EXPLOSIVES WASHING OUT TECHNOLOGY FROM ARTILLERY AMMUNITION

Przemyslaw BORKOWSKI¹, Jozef BORKOWSKI¹, Dariusz WOZNIAK^1
1Koszalin University of Technology, Unconventional HydroJetting Technology Center

Abstract

The methodic of high explosives materials washing out process from old artillery ammunition using high-pressure waterjet technology are discussed in the paper. Experimental results let to define explosives washing out mechanism and its potential effectiveness. Methodics and experimental range concerning title process are presented too. Test results let to elaborate so-called imitator of high explosives ensuring safety of the experiments. Finally, there were presented exemplary structures of washed out explosives and methods of its utilization.

Author Keywords :

high-pressure water jet, artillery ammunition, explosive materials

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

SOLID WASTE UTILIZATION WITH HIGH-PRESSURE HYDROJETTING TECHNOLOGY

Jozef BORKOWSKI¹, Artur SOKOLOWSKI^1
1Koszalin University of Technology, Unconventional HydroJetting Technology Center

Abstract

Intensive increase of our life standard and technique development involves systematic increase of waste generation but their structure is changing causing dangerous environmental situation. In order to increase the efficiency of traditional waste utilization methods, a new conception of high-pressure water jet technique was introduced. A few original experimental stands were built in order to evaluate water jet usefulness in that matter. Experimental results let to define effectiveness of that method in the aspect of solid waste disintegration and densification. There were also realized experiments of waste initial separation using compressed air. Results obtained in that scope are promising giving a chance to mechanize that separation process and consequently to reduce waste dump volume.

Author Keywords :

high-pressure water jet, municipal solid waste, utilization

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

CONCRETE CUTTING USING HYDROJETTING TECHNOLOGY

Przemyslaw BORKOWSKI^1
1Koszalin University of Technology, Unconventional HydroJetting Technology Center

Abstract

Technological equipment and high-pressure accessories used for building materials treatment with water pressure of 300 MPa and work medium rate over 0,5 dm³/s are presented in the paper. Reinforced concrete cutting and examples of its spalling using high-pressure abrasive-water jet are also presented in. All those research were carried out for variable work conditions, taking into consideration influence of water pressure, type and size of abrasive also work head positioning. Research results let to analyze cutting process that helped to create concrete cutting model.

Author Keywords :

high-pressure abrasive-water jet, concrete cutting

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

DEVELOPMENT OF SOFT METALS GRINDING AIDED WITH WATERJET

Jozef BORKOWSKI¹, Przemyslaw BORKOWSKI¹, Adam SZPAKOWICZ^1
1Koszalin University of Technology, Unconventional HydroJetting Technology Center

Abstract

Conventional grinding of soft and ductile materials is seriously hindered of the grinding wheel working surface loading and an accompanying loss of its grinding ability. The conditions of grinding operations improve considerably with the water jet application of the pressure level of 6÷8 MPa for cleaning the grinding wheel. This report deals with the problems connected with grinding of aluminum and copper alloys. The dependences and relations between the cutting parameters (cutting speed, depth of cut, grinding wheel parameters, and workpiece material) and water jet parameters (type of nozzle, flow ratio, pressure, used liquid) on the one hand and workpiece surface quality an the life of the grinding wheel on the other hand are presented in this paper. It was concluded that the application of proper grinding wheel cleaning condition could increase by several times the time of its life, which present aspects of application of such a way grinding wheel working surface cleaning.

Author Keywords :

grinding, waterjet

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2010, Poland

HIGH-PRESSURE ABRASIVE-WATER JET CUTTING COMPARISON WITH CONVENTIONAL METHOD OF MATERIAL SEPARATION

Przemyslaw BORKOWSKI^1
1Koszalin University of Technology, Unconventional HydroJetting Technology Center

Abstract

Important features of materials cutting with high-pressure abrasive-water jet compared with oxygen as well as plasma cutting are presented in the paper. Comparison of those different methods is based on relative factors presenting percentage values. The following parameters were taking into account: material machinability, cutting process conditions and technological possibilities, chemical emissivity of work stand dustiness as well as ecological disadvantages of the process. Analysis of those parameters shown out multi-aspect advantages of material cutting with high-pressure abrasive-water jet.

Author Keywords :

abrasive-water jet, systems for abrasive-water jet cutting