Adrian Popescu

Research Concerning the Optimum Extrusion Temperature for Reinforced Polyamide

Polymeric materials extrusion is a very complex manufacturing process opened for new research. In this paper the authors use for extrusion polyamide 6.6 reinforced with 20% glass fibres. This material offers very good mechanical, thermal and frictional proprieties. The improvement of these proprieties can be realized through the optimization of the extrusion process. Temperature is a very important parameter for obtaining good quality products, so to choose the proper values of it, is an interesting challenge. It was proved that the main influence upon the products quality have the temperatures from the metering zone and from the forming zone so the optimization of these is of maximum importance for the quality of the products. The Response Surface Method (RSM), based on ANOVA - Analysis of Variance model was used for optimization the temperatures from the metering zone and from the forming zone.

Custom Implants: Manufacturing Principles and Determination of Psychological Price

This paper presents the basic principle for achieving a custom implant from biocompatible materials with the human body using Additive Manufacturing technologies. Due the fact that is a new product which will be introduced on the market, a marketing study was needed. This study presents also the mathematical, analytical and graphical modeling of the psychological price, for a custom implant type cranioplasty / hip prosthesis / spinal implant. The assessment of psychological price for a custom cranioplasty implant, that is not the object through curative Romanian health programs, bring relevant information on the knowledge of maximum and minimum limits that the purchasers, potential consumers, are willing to accept, so the price at which the proportion of consumers potential is the greatest.

Experimental and Theoretic Research Regarding Extrusion Optimization for Reinforced Polyamide (PA 6.6 – 10 % GF)

This paper presents the possibility of extrusion optimization using Design Expert software for statistical analyze and also for the recommendation of some manufacturing data. Mechanical characteristics are determined on samples from extruded tubes. On these samples, ANOVA (Analysis of variance) software is used, in order to determine the optimal values of the temperatures in different zones. The material is polyamide 6.6, reinforced with 10 % glass fiber (PA 6.6 – 10 % GF). The authors want to present the influence of the reinforcement degree upon some mechanical characteristics of the products made by extrusion. Considering the homogeneity of the polymeric melt the product’s quality will be analyzed. During the extrusion process a series of parameters (extrusion speed, the pellets feed, processing temperature etc.) are involved and they must be taken into account to achieve calibrated and qualitative products.

Research Concerning Chalk‘s Influence on Composite-Based Melamine's Compressive Strength

The main goal of the research is to find new recipe for composite based melamine, in order to obtain less toxic products. In the paper there are presented the equipment and the experiments made by the authors in order to obtain samples from a composite material made from melamine and different ratio of chalk. A compression test was performed and the results were graphically presented. A mathematical approach was realised and the results are presented.

Experimental Research Regarding the Tensile Strength of some Reinforced Composite Materials

The fiber-reinforced polymer composites are of great scientific and technical interest and a very impressive development. This justifies both the development of the research in this area, and the extension of the production of such materials.This paper presents research regarding three different composite materials, plates of carbon fibre, glass fiber and Kevlar in epoxy matrix. The mechanical characteristics of plates made of composite materials (CM) reinforced are presented. Based on the results, a comparative study between the reinforced materials used to manufacture the plates of CM is carried out.

The Mould Design for Production of Plastic Component by Injection Moulding Technology

The article deals with the design of the mould for plastic component production by injection moulding technology. There are described the basic steps of whole design process how to choose and design the suitable components with respect to fulfilling the technology requirements necessary for high quality products. The mould contains also the rotary cores with respect to the shape and dimensions of produced part, especially the thread surfaces. The mould flow analysis was carried out for the functionality demonstration.

Some Researches Regarding the Surface Quality when Drilling Carbon Fiber Reinforced Composites

In this paper, an attempt has been made to model the surface roughness through response surface method (RSM) and ANOVA when drilling CFRP composites. Drilling is the most common machining process applied to CFRP. However, the users of this kind of composites are facing difficulties to machining it, due to its properties. Because of the bad effects that lubricants have on the fiber-reinforced composites, the machining of these materials is performed without coolant. On the other hand dry machining offers the risk of a thermal damage induced by high process temperatures. The current experimental analysis is focused towards determining process temperatures with different tools and drilling parameters.