Advances in Materials, Mechanics and Manufacturing

Biodegradable poly(ester-urethane)-based scaffolds with an elastomeric character offer special mechanical properties by reducing the mismatch of Young’s modulus between rigid thermoplastic scaffolds classically used, and soft and dynamic tissues to regenerate (skin, tendons, muscles). In this study, porous scaffolds had been elaborated by using a high internal phase emulsion process with variable pores size (150–1800 μm), a porosity of 85% and sufficient strength making them suitable for cell culture, tissue formation and therefore various tissue engineering applications. The scaffold mechanical properties were evaluated at different frequencies. Analysis by conventional quasi-static mechanical tests (0.1 Hz) demonstrated that the scaffolds exhibited an elastomeric character with an effective Young modulus of 165 kPa. In addition, the determination of dynamical viscoelastic parameters was assessed at higher frequencies (MHz–GHz) by the ultrasonic pulse echo method (10 MHz) and micro-Brillouin inelastic light scattering (13 GHz) analysis. Our measurements revealed a strong increased of the Young modulus with increasing frequency and a linear correlation (log-log scale) between stiffer hypersonic (MHz–GHz) modulus and softer low-frequency one. The slope α = 0.194 is characterizing the viscoelastic behavior of this polymer. In addition, micro-Raman was coupled to the micro-Brillouin to determine at the same location the chemical properties of the polymer.

Recycling of Al 2017 alloy machining chips via powder metallurgy route including hot compaction and sintering processes was studied. This method was proposed in order to elaborate Aluminium products based on Al 2017 alloy powder. To obtain desired chips with small thickness, the optimal cutting conditions are applied. The chips obtained after turning operation had undergone a milling step by varying milling times. Then, these powders were hot compacted and then sintered at various temperatures and times. The results indicated a decrease of particle size of 2017A alloy by increasing the milling time which reaches 70 µm after 20 h of milling. This is due to the successive plastic deformation which makes particles hard and brittle. By using DSC analysis, a high level of stored enthalpy release is observed due to the milling process where two kinds of structural changes are presented. Also, heating the deformed powder provides the elimination or the rearrangement of some dislocations and the release of the residual stresses stored in the powder. Then, it can be deduced that higher densities are obtained at higher sintering parameters (t2 = 90 min, T2 = 550 °C) which explained by particle size refinement during the milling step and the activated phenomenon of diffusion during the sintering step.

Additive manufacturing is a revolution for many sectors of the industry. These new manufacturing processes allow a substantial saving of raw material while optimizing the geometry, and at the same time, reducing development costs, by reducing the time between the concept and deployment phases of a product. A 3D printing device using a Cold Metal Transfer (CMT) arc welding station to melt a metallic filler wire is developed to build titanium parts by optimizing the process parameters to control metallurgical and mechanical properties of parts. In this study, two parameters (wire feed speed and movement speed of the robot) have been studied. Their impact on the metallurgical, dimensional process stability and mechanical properties of materials have been analyzed. Microstructure and mechanical properties vary depending on the energy expended during manufacture. This energy remains constant or decreases respectively when the wire feed speed or the robot head travel speed increases. Indeed, the electric generator adapts its power according to the speed of the wire. Regardless of the energy parameters, the movement speed of the robot seems to influence the wetting angles, the depth of melted zones, remelted and heat affected zones and the metallurgy with a refinement of the substructure of the deposits.

Geopolymers obtained following acidic activation represent a promising future material with their different advantages, namely high mechanical strength, excellent dielectric properties and important chemical stability. In the present research, Phosphate-based geopolymer was prepared from metakaolin, as the aluminosilicate precursor and commercial phosphoric acid H₃PO₄, as the activator precursor. These reagents were mixed with (Al/P) molar ratio and solid/liquid (S/L) volume ratio equal to 1. To investigate the obtained material structure, different techniques were used as Fourier Transform Infrared spectroscopy (FTIR), magic angle spinning nuclear magnetic resonance (MAS-NMR) spectra of ²⁹Si, ²⁷Al and ³¹P, X-ray diffraction powder (XRD) and scanning electron microscopy (SEM). As well, the same techniques were used to characterize the used aluminosilicate precursor, which is metakaolin. As a result, the formation of a first aluminum phosphate geopolymeric network dispersed in a second one based on (Si–O–T) units was proven, with T=Si, Al and P. The XRD analyze shows the formation of an amorphous material. In fact, any crystalline phases were observed. Accordingly, the Phosphate-based geopolymer was considered as a composite material composed from two amorphous networks: the aluminum phosphate geopolymeric network which plays the role of reinforcement and the silicate network which represents the matrix.

Production in industry is limited by the vibration phenomenon, but it is also at the root of the problems of surface quality and degradation of the cutting tool and the machine. The vibration has been widely studied and modeled. Most models aim to model the machining system using a model with a single degree of freedom or two degrees of freedom where the cut is stable depending on the dynamic properties of the part—tool—machine. The main objective of this article is to model numerically in three dimensional the dynamic behaviour of the machining system during turning operation while considering the vibration of the unit workpiece and cutting tool. The writing matrix of the differential equation of movement of the system was developed by neglecting their damping effect where the cutting tool and the workpiece are studied and characterized together by matrices mass and stiffness. The finite element method is used to obtain the global matrices mass and stiffness of the machining system by assembling the elementary matrices of the cutting tool and the workpiece by considering them as two elastic deformable beams. We have identified after the assembly that there is a matrix coupling. This method is also used to identify the eigens characteristics of the system using the Matlab software as a numerical simulation tool during a straight turning and to analyze the influence of the cutting tool position and its mechanical characteristics on the dynamic behaviour of the machining system. The dynamic model of the machine was obtained by a numerical modal analysis to determine the modal displacement of the machining system which is influenced by modifying the position of the cutting tool have a great influence on the behaviour dynamic and the modulus of elasticity which. Each machining system being machined has its own frequencies and modes, for frequencies the system is stable and others unstable. The paper concludes with numerical results for this three-dimensional numerical model show that in order to have a stable system, it is obligatory to avoid the eigens modes and frequencies of the machining system.

In this paper, we present a numerical simulation of a round jet impacting a polymer plate using the coupled Smoothed Particle Hydrodynamics (SPH) and Finite Element (FE) methods. Numerical results are compared with the results from other simulations carried out by other numerical method based on the Eulerian Lagrangian (CEL) formulation presented in the work of [1]. Results from the CEL method were experimentally validated in the work of [2]. A water jet with a spherical head was used at an initial speed of 570 m/s to impact on a flat plate made of Polymethyl-Methacrylate (PMMA). To simulate the entire process, the SPH method was used to model the water jet and the FE method was used for the modeling of the PMMA structure. The distribution of the pressure on the impact surface and the resulting deformation of the structure were discussed. A Numerical model was developed using ABAQUS/Explicit version 6.14. Results of the coupled SPH-FE simulation were further validated. It is demonstrated that the (CEL) method presents smoother curves compared to the SPH method. The numerical model using the SPH/FE method proves its ability to produce the entire physical processes of the impact.

Shears with the parallel knives are used for cutting bars to desired lengths from the mill stock. The knives are manufactured mostly from tool steel by heat treatment, while hard surface welding mainly used in repairs damaged parts. This paper presents a comparison of the ordinary knife fabrication from the tool steel X210CrW12 by heat treatment and knife fabrication from the structural steel St 52-3 by hard surface welding. Detail procedure of knife fabrication from tool steel is presented. The material X210CrW12 is received from supplier in soft annealed condition. After machining, following stress-relief annealing, preheating and austenizing, quenching, tempering and cooling on the end. The procedure of knife fabrication from the structural steel is simpler. The material St 52-3 is supplied in normalized condition. After machining and preheating, first welding is welding of ductile and high strength build-up layer, then following hard surface welding. An advantage of the fabrication by hard surface welding compared to the ordinary knives fabrication from tool steel is lower price, time of fabrication and possibility to extend total durability by several times repeating hard surface welding, but this requires skilled maintenance workers.

The effect of post-heat treatment process on TiO₂ nanoparticles (NPs), prepared by hydrothermal-assisted sol-gel method, was investigated through measurement of the band gap energy, crystal size, photocatalytic activity and antibacterial efficiency of TiO₂ NPs. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and UV-Vis spectroscopy were used to characterize treated as well as untreated TiO₂ nanoparticles. Methylene blue (MB) dye was used as a pollutant model in order to investigate the photocatalytic activity of as-prepared TiO₂ nanoparticles. The antibacterial activity of TiO₂ nanoparticles was assessed under UV-A irradiation by testing the growth inhibition of two bacterial strains: a Gram negative bacteria Stenotrophomonas maltophilia (S. maltophilia) and a Gram positive bacteria Micrococcus luteus (M. luteus). The results indicate that the crystal size increases from 13 to 20 nm for untreated (NT) and treated nanoparticles, respectively. FTIR results show that heat treatment eliminates inorganic impurity. SEM micrographs prove that annealing does not modify the morphology of nanoparticles, however, particle size increases due to calcination. In addition, post-heat treatment at 500 °C for 2 h decreases the band gap energy (from 4.35 to 3.25 eV) and consequently enhances significantly the photocatalytic activity as well as the antibacterial performance of as-synthesized TiO₂ nanoparticles.

This paper presents a probabilistic analysis approach applied to finite element analysis for modeling a cracked aluminum plate repaired with composite patches under cyclic loading. For this, it is necessary to have a mechanical model and a probabilistic model correctly representing the behavior of this type of structures. The finite element method reported in this paper to analyse the evolution of the stress intensity factor and to evaluate the effect of the composite patch on increasing the life of cracked structures. The uncertainty of the geometric characteristics and mechanical properties of the Glass/Epoxy repair patch was presented in this study. The Probabilistic method applied to finite element modeling provides another alternative medium for structural analysis of repairing aluminum plates to achieve a robust and reliable design in a more efficient manner. The Monte Carlo simulation was used in this study and the reliability in this context is defined as the probability that the stress intensity factor is less than the toughness under cyclic stress. According to this study, the most influential parameter that has a significant effect on the stress intensity factor is the thickness of the adhesive and the thickness of the patch that must be tightly controlled.

In this paper, a design of a mini parabolic concentrator is studied. The interior surface is covered with a reflective layer and equipped with a cylindrical receiver in its focal position. To validate the sizing of the main parts of our system and to make our mechanism resistant against external forces, we used the numerical simulation carried out on. Currently, solar concentration technologies present opportunities for commercial exploitation. These technologies are based on collectors that concentrate solar radiation and heat a heat transfer fluid at high temperature. Hence the idea of designing and building a parabolic solar concentrator which is composed of a reflective surface that concentrates the incident radiation to its focus. Its size obviously depends on the solar power required. This type of concentrator has the highest thermal efficiency which is around 75%. Our system consists mainly of a dish, a cylindrical receiver placed in the focal position, a recessed reflector on a nacelle, a counterweight, a support supported by a pylon and a frame fixed to the ground. The system is composed of 2 main classes. It has two degrees of freedom of rotation: class 1 to adjust the azimuth angle and class 2 for the angle of elevation.

In this work, an experimental investigation was proposed for the evaluation the wear resistance of hybrid polymer composite inter-layer of Petiole date palm fiber (PDPF) and glass fiber (GF). In order to enhance the interfacial of hydrophobic fibers (PDPF) and hydrophilic (Vinylester resin), chemical treatment was proposed based on 5% NaOH for 48 h. Besides, the glass fiber (woven) was used in order to increase the specific stiffness and the dimensional stability of specimens. The manufacturing of four hybrids specimens was done using a VARTM process [(30PDPF/0GF), (20PDPF/10GF), (10PDPF/20GF) and (0PDPF/30GF)]. The wear characteristics were evaluated at a sliding distance of (1000 m), sliding velocity (1.7 m/s) and applied loads (20 and 40 N). Scanning electron microscopy was performed on both treated alkali fiber and worn surfaces of hybrid specimens to evaluate the surface modification and wear mechanisms, respectively. The adding of glass fiber to PDP fibers was advantageous on the wear resistance, where it improved the wear resistance of 30PDPF/0GF around 190 and 310% as compared to (20PDPF/10GF) and (10PDPF/20GF), respectively. The adding of loads was disproportional to wear resistance. The SEM of worn surfaces showed debonding and bending of fibers, and fragmentation, fiber broken, and deformation on the resinous regions. In the end, the hybridization by 20% of glass fibers exhibits a high wear resistance relative to its nature (partially bio-friendly) and price.

In this paper, Plackett–Burman design was employed for screening factors influencing phosphate-based geopolymers consolidation time, through comparing the differences between each factor at two levels. This design screens 9 factors through 12 experiments. Considered factors are: Si/P molar ratio, curing temperature, heating time, calcination of used aluminosilicate precursor, mold’s condition, aluminosilicate particle size, chemical composition of aluminosilicate precursor, pH and acidic solution. Results show that curing temperature, calcination of aluminosilicate precursor, mold’s condition and aluminosilicate particle size factors are responsible for 97.79% of the consolidation time variation. The most significant effect is attributed to curing temperature, with a contribution of 73.46%. This factor presents a negative effect. Thus, its increase generates the decrease of consolidation time. This result can be explained by the endothermic character of the geopolymeric reaction. In fact, the increase of the curing temperature activates the reaction which accelerates the kinetics of consolidation. The impact of the other factors like Si/P molar ratio, the heating time, nature of aluminosilicate precursor, pH values and the acidic solution is very small and it can be neglected, in the studied conditions. These factors did not present a kinetics influence and they haven’t a direct effect on the consolidation time.

The properties of the coatings produced by plasma spraying are essentially related to the adhesion force between the projected particles and the substrate. The melting of the substrate can significantly improve this adhesion strength. In this paper, a 2D axisymmetric model was developed to simulate the impact of a fully melted particle of alumina in droplet form on an aluminum substrate, taking into consideration the melting of the substrate and its re-solidification using Ansys Fluent 14. Equations of fluid dynamics and energy including phase change are solved in a structured mesh by finite volume discretization. The volume of fluid method (VOF) is used for tracking the free surface of the droplet. An enthalpy-porosity formulation is used to model the solidification. The effect of the initial temperature of the droplet on the melting of the substrate has been studied. Substrate fusion was observed before the droplet spread completely. The volume of molten substrate increases over time, to reach its maximum, then it begins to decrease because of its re-solidification. The substrate is completely solidified well after the solidification of the droplet. It has been observed that the volume of the molten substrate is greater when the initial temperature of the droplet is important, which can improve the adhesion strength of the coating.

Shearing of bulk material is a cost efficient method of producing billets for subsequent forging operations. The procedure of rod shearing is characterised by high billet output quantities without metal removal. This technique is widely used in industrial processing of steel materials. Aluminium billets however, are mostly produced by sawing, causing higher manufacturing costs due to comparably low output. The aim of this paper is an enhancement of sheared aluminium billet quality in order to fulfil industrial standards required for further forging operations. To enhance the quality of sheared aluminium billets, the shearing process parameter clearance (distance between the blades) was varied to create billets of four different aluminium alloys, as EN AW 5754 (UNS A95754), EN AW 5083 (UNS A95083), EN AW 6082 (UNS A96082) and EN AW 7075 (UNS A97075) in different conditions. The quality of sheared billets is assessed by analysing inclination angle, waviness and surface defects of the sheared parts with 3D-measurement. In the investigation, it can be shown that the tensile strength of the investigated alloys influences the billet surfaces. High tensile strength results in positive billet quality. Further, small clearances show best results concerning inclination angles, while higher clearances result in decreased waviness.

Bar shearing is an important operation that supplies semi-finished billets to many metalworking processes such as stamping, extrusion and precision forging. Temperature rise and stress state variation during shearing have a great influence on material behavior and rupture mechanics. Consequently, accurate simulation of shearing requires a precise material modeling. The studied material is the AW-6082 aluminium alloy. This paper concerns principally the improving of shearing simulation by means of adequate modeling of ductile failure. The major contribution of this study is to present a relatively uncomplicated method to calibrate a decoupled damage model. To this purpose, the Hooputra ductile damage (HDD) model is selected since it reflects the influence of different stress states and temperature variations on the mechanical failure of the material. The triaxiality is considered as indicator of the stress state. The identification of the parameters of the damage model is based on a hybrid experimental-numerical analysis of three characterization tests, namely tension tests on smooth bars, tension tests on notched bars and shear tests. The obtained calibrated damage model is employed to simulate shearing. The fracture is simulated using the “element deletion” technique. Computed shearing results are eventually evaluated by comparing simulated force-displacement curve to experimental one.

A multibody system can be considered as an assembly of interconnected components: flexible bodies, rigid bodies, joint and unit control. This paper describes an analytical methodology for the predesign of a multibody system mixing rigid and flexible structure and regarding the vibrational aspect. Indeed, one of the principal aspects that limit performance in mechanical systems is the presence of vibrations. This contribution is based on the object-oriented modelling with Modelica language. Structural engineers frequently encountered problems arising from deflection of flexible structure such as plate and beam under moving load. In this paper, we study the interaction between a dynamic exciter moving with a constant velocity over a flexible beam resting on an elastic foundation by using the theory of dynamic response of Euler Bernoulli beam. The study of the moving load is of great importance in the transportation field. This methodology will be illustrated to the railway system. In fact, the dynamic response of a railway track subjected to a moving train load may be simplified as a beam traversed by a moving load. An analytical based approach is considered for the dynamic simulation of the flexible multibody system. The effect of some parameters on the dynamic response of the system has been studied.

The implementation of controller for a suspension system should have as low as possible complexity. The engineer should find the appropriate way to apply algorithms with low scaling parameters to achieve the required performances such as: ride comfort ride comfort, suspension spaces and dynamic tire load. For this reason, an appropriate way should be invented to apply the algorithm that gives the force generated by each actuator based on the motions of the vehicle which is received from various sensors located at different points of the vehicle. Two control strategies are investigated: First, the Active Disturbance Rejection Control (ADRC) control is investigated for showing its applicability to ameliorate ride comfort of passengers. Second, a traditional skyhook control scheme equipped with an Magnetorheological (MR) damper is investigated to show its superiority to give good performances of road holding and suspension space limits compared to the introduced intelligent controller ADRC. Furthermore, this semi-active controller is known as a simple control strategy with straightforward tuning process where only one gain parameter is needed for the implementation process. A simple prototype of quarter-car suspension is given to show the effectiveness of the introduced controllers. MATLAB/Simulink environment was used for investigating the comparison between the proposed techniques.

Although the dynamic behavior of rectangular plates has been the subject of much research for many decades, it remains of a crucial importance in various engineering fields and some edge conditions have not yet been treated, especially those involving edges connected to distributed rotational springs and non-linear vibrations. Also, in the practice of Modal Testing, theoretical models are needed for quantitatively estimating the flexibility of the real plate supports. A complementary work is presented here corresponding to plates connected to a distribution of rotational springs at two opposite edges vibrating in the geometrically non-linear regime occurring at large vibration amplitudes. To build the plate trial functions, defined as products of beam functions in the x and y directions, the mode shapes of simply supported beams connected to rotational springs are first calculated. Then, after exposing the general formulation of the non-linear problem, based on Hamilton’s principle and spectral analysis, the plate case is examined. Using the single mode approach, the backbone curves are determined, giving the non-linear frequency-amplitude dependence for plates having different combinations of stiffness and aspect ratios. It is noticed, as may be expected, that the obtained hardening non-linearity effect becomes more accentuated with increasing the rotational spring stiffness.

This paper addresses the temperature effects in abrasive milling of polymer matrices used in fibre reinforced polymers (FRP). Current knowledge of fibre reinforced polymers machining still remains understudied and involves challenging issues for their optimal use. A design of experiments including three matrix types was constructed to analyse the heat distribution due to cutting conditions. The cutting speed N, depth of cut a_p, and feed rate V_f were kept constant in this study. Milling tests were performed on resin specimens using an abrasive grinding wheel and 5-Axis CNC Machine with maximum spindle of 12,000 rpm. Three resinous matrices, namely, polyamide, Epoxy and Polyester were considered for the design of experiments. Equidistant thermocouples type K were embedded within the median plan of the specimen in order to record the temperature histories during cutting step. Measurements showed unequal temperature peaks on the three matrices referring to heat losses irrespective to matrix type. Temperature distribution within the specimens informs about heat evacuation during tool advance. The temperature histories reveal three typical regions regardless the matrix type being milled: fast heating period, maximum peak, and a relatively longer cooling period giving rise to room temperature. Those three periods vary sensitively with the resin properties.

In many engineering applications (automotive, computer and mobile device industries, etc.), magnesium alloys have been widely used owing to their interesting physical and mechanical parameters. However, magnesium alloys are identified by the low ductility at room temperature, due to their strong plastic anisotropy and the yielding asymmetry between tension and compression. In this work, the ductility limit of a rolled magnesium AZ31 sheet metal at room temperature is numerically investigated. This investigation is based on the coupling between a reduced-order crystal plasticity model and the Marciniak–Kuczyński localized necking approach. This reduced-order model is used to describe the anisotropic behavior of this material taking into account the strong plastic anisotropy (e.g., yielding asymmetry between tension and compression) due to the limited number of slip systems (i.e., twinning mode). To accurately describe the plastic anisotropy due to slip and twinning modes, a combination of two separate yield functions (according to Barlat and Cazacu) is used. The coupling between the adopted constitutive framework and the Marciniak–Kuczyński instability approach is numerically implemented via an implicit algorithm. Comparisons between experimental results from the literature and numerical results obtained by using our calculation tool are carried out to validate the choice of the reduced-order crystal plasticity model.

This paper investigates the effect of capacity tightness on performance of multi-objective particle swarm optimization (MOPSO) algorithm in solving the multi-item capacitated lot-sizing problem with consideration of setup times and backlogging (MICLSP-SB). The considered problem is formulated as a multi-objective optimization model. The formulated model aims at simultaneously minimizing two objective functions. The first one seeks to minimize the total cost, which the sum of production, setup and backlogging costs. The second one seeks to minimize the total inventory level. Sensitivity analysis is performed on a set of generated problem instances. The capacity tightness factor is defined as the ratio between the required capacity and the total available capacity. Three levels of capacity tightness factor are considered for each problem instances. The metrics, which are used for evaluating the performances of the MOPSO algorithm, are number of Pareto solutions, spacing and computational time. Results of sensitivity analysis show a considerable impact of capacity tightness on performances of MOPSO algorithm in terms of number of Pareto solutions and computational time. This investigation offers to the decision makers a clear insight into the performances of MOPSO algorithm in solving the considered MICLSP-SB depending on problem features especially, the capacity tightness factor.

Damping plays an important role in the simulation of the mechanical system. Various damping models are used such us non-viscous damping, coulomb damping, and hysteresis damping. For mathematical convenience, Rayleigh damping is usually used in a gear system to model damping. Rayleigh damping coefficients (RDCs) can be identified using the frequencies when the degree of freedom of the system is low. However, for complex systems, problems of selecting the frequencies of the RDCs are presented. The classical methods used only a constant damping ratio for all modes can underestimate the dynamic response. Continuous wavelet transforms (CWT) method is recently used to identify the modal parameters such as the natural frequencies and the damping ratios. This study presents initial research into the use of the CWT method to select the optimal frequencies of the Rayleigh damping formulation to identify RDCs. The RDCs are identified using the modes contributing to the dynamic response of the two-stage gear system. The modes that remarkably affect the dynamic responses are determined on the basis of the modes corresponding to the maximum values of the wavelet spectrum. The proposed method is validated using the simulated responses of a two-stage gear system and compared with the classical methods.

Technology evolution and the demand of modern life have led to more using for machine tools which are the basic energy consumption devices in manufacturing. Subsequently, CO₂ emissions in the atmosphere will increase, causing several climate changes such as the greenhouse effect. As the resources and energy in the earth are limited and getting fewer and fewer, sustainable manufacturing is gaining more and more attention to produce the same product with less negative environmental impacts. In this paper, a mono-objective optimization for sustainable manufacturing is presented. Such approach needs a balance between economic and ecological aspects. Thus, the objective of this work is machining product with less environmental impacts by minimizing consumed energy with respect to technological and economic constraints. The consumed energy is modelled based on the dynamic behavior of the cutting forces. A case study of single pass of face milling operation is carried out using the particle swarm optimization tool. The surface quality is adopted as an objective in this work. Three decision variables are taken into account during the resolution such as rotational speed, axial depth of cut and feed per tooth. Results show that the proposed optimization model has a great efficiency to find a trade-off between the four objective functions in order to minimizing them.

The aim of this paper is to investigate the optical properties of the recycled polymer during numerous internal reprocess using experimental design. The process conditions (material temperature, mold temperature, injection rate) and recycling on the gloss and colorimetric properties of polypropylene containing 2 wt% of pigment was studied. Several injection parameters and cycles numbers must be tested. One most limit for this kind of study is the large number of experiments that requires longtime and significant investments. The idea is to vary three injection parameters (Temperature of material, Temperature of the mold, injection rate) for five injection cycles using statistical approach. The three variables (materiel temperature, mold temperature and injection flow) were investigated at three industrial used levels. The number of recycling varies from cycle 0 to cycle 4 at five levels. The complete matrix for screening was designed using D-optimal quadratic design. The experimental design was generated with the statistical software MODDE 10.1-Umetrics. A set of 45 experiments was carried out to determine the influence of injection parameters and recycling on the appearance properties of samples. The statistical software package Nemrodw^® version 2007, LPRAI (Marseille, France) was used to analyze the experimental design.