Papers by Keyword: Thermoplastic

Abstract: In order to expand the possibilities of practical application of polymeric materials we studied syndiotactic 1,2-polybutadiene (1,2-SPB). The experimental procedure and the MV-002 device for determining the breakdown voltage and electrical breakdown of a polymer are described in detail. Mathematical models of the dependence of the breakdown voltage of the polymer on the frequency and magnitude of the electrical breakdown of the polymer on the thickness of the sample have been built and studied. Regression analysis was used for mathematical data processing. The reliability of the results obtained is proved by the methods of test statistics.

Abstract: Reliable composite forming experiments are required to characterize composite formability, to aid material development, and to validate process simulations models. Due to practical reasons, however, typically a limited amount of forming configurations is studied. The objective of this study is, therefore, to develop a methodology for obtaining controlled forming results in a wide range of configurations. Press forming experiments using a dome geometry were used to explore the formability of two commercial unidirectional thermoplastic composite materials. A variety of forming configurations was employed by changing the blank dimensions and layup. The observation of wrinkling defects was simplified by leaving an additional 3 mm tool gap. Blank width and layup had the most influence on the wrinkling severity, followed by blank thickness and length. Quasi-isotropic layups were found to produce wrinkles in nearly all cases, confirming a difficulty in general to form double curved parts. The size and number of wrinkles in these layups were found to change with the stacking sequence. Cross-ply layups showed better formability, but significant wrinkles were still observed depending on the orientation of the blank relative to the layup. The formability experiments using a dome geometry provided a reliable methodology for controlled forming results in many configurations using a generic toolset. Additionally, a comprehensive comparison of formability for two commercial thermoplastic UD materials in a variety of scenarios was provided.

Abstract: Out of autoclave composite manufacturing is a process that achieves same quality as an autoclave process but through different method and one of them is thermoforming process in which, it can save the process cost and time. Recently, the fabrication process to fabricate thermoplastic composites by using thermoforming method becoming more popular among the thermoplastic research area. The simulation process is applied to enable the prediction of defects as well as to study the behavior of the process at early stage using simulation analysis to avoid trial and error during fabrication. To simulate the simulation, there are several factors and parameters need to be considered so that the defects could be avoided due to the excellent and poor formability will be linked between the fabricated samples in Aniform and the manufactured products. In this study, Two-Folded Clip panel mold type has been chosen to simulate the fabrication process. The results show the tensioner of AUY-50 is the best tensioner to be used in this research due to the significant of the result of press formed laminate quality with no voids appeared.

Abstract: The article contains the analysis of thermoplastics used in prototyping machine parts. We used several types of experimental samples with different filling percentages. The equipment on which the experimental studies were carried out is shown. During the experiment, a specialized tensile testing machine was used. The experimental samples were installed in the developed centering device. Normal conditions were observed during the tests. The results of an experimental tensile study of PLA-plastic specimens are presented. The typical stress-strain diagram of an experimental sample is described, which describes the dependence of stress on relative deformation. An equation of the linear dependence of the tensile strength on the percentage of filament filling has been compiled, which makes it possible to determine the tensile strength of the product at any percentage of the filling of the plastic filament. The assessment is adequately verified by Fisher's criterion. Recommendations for filament filling in prototyping machine parts are given.

Abstract: The paper presents a series of experimental researches performed using the design of experiments method RSD (Response Surface Design) for modeling and optimizing the welding process of PE 100 pipelines, used in natural gas distribution. In this sense, the aim was to analyze the influence of controllable factors such as pressure, temperature and time on the objective functions, aiming to obtain certain characteristics of the welded joint. By modeling the welding process, based on the results obtained, an optimal welding procedure was established and validated to meet the conditions imposed on the objective functions.

Abstract: Material selection is one of the vital and critical steps in the mechanical design process. In recent times, various tools based on the multi-criteria decision-making process are used successfully to cope with such complexity in material selection. .This work provides appropriate methods and tools to find the optimum thermoplastic polymer reinforced natural fiber composites. The material selection applied using a decision-making model that consists of the „Technique for Order of Preference by Similarity to Ideal Solution“ (TOPSIS) and „Vlsekriterijumska Optimizacija I Kompromisno Resenje“ (VIKOR) methods in order to rank of the materials according to applied criteria. Analytical Hierarchy Process (AHP) method was performed in order to determine the weighting of the material properties or criteria. Rank the materials were gained by using ranking scores as results of the methods use. The results offer that the best polymers were found to be the LDPE and Nylon 6,6. It was proved that the multi-criteria decision-making model is an application for solving complex material choice decision problems. This model can be applied to other engineering applications with any number of alternatives and criteria for material selection.

Abstract: The diglyceryl phthalate epoxy resin contains a benzene ring in its molecular structure, and its molecular weight is small. In addition to the generality of epoxy resins, it also has the advantages of low viscosity, moderate reactivity, high adhesion, good compatibility, excellent electrical insulation and ultra-low temperature, and good weather resistance. It has good adhesion with carbon fiber, and it is suitable to make carbon fiber composite material. Based on this background, this article mainly focuses on the seat art design, and uses the wrapping method to analyze the preparation of the carbon fiber composite resin matrix. The optimal reaction conditions are determined by changing the reaction during the preparation of the thermoplastic resin matrix. / PA = 1.9, esterification time 120min, cyclization time 70min, reaction temperature 110 °C, amount of promoter water 6g, concentration of cyclizing agent sodium hydroxide solution 30%. The resin synthesized in this case is a light-yellow transparent liquid with an epoxy value of 0.51 (mol / 100g).

Abstract: In this work, a smart thermoplastic window frame for a regional aircraft has been designed and manufactured. The aim of the work was to design a smart sensing system for monitoring of a bonded thermoplastic aircraft window frame in operation. The conductive tracks were designed and inkjet-printed onto the window frame and their disruption was used as an indication of a damage event created within the bondline. Based on the electrical resistance measurements, the method was able to detect a damage that was created in the bondline due to an impact event. To verify the proposed methodology, ultrasonic C-scan inspection was also performed.

Abstract: Poly (diethylene glycol) adipate diol, tolylene-2,4-diisocyanate, 1,3-bis (3',4-dicarboxylphenoxy) benzene and 1,4-bis (4'-aminophenoxy) biphenyl were used as monomers to form statistical copoly (urethane-imide) s with variable content of imide blocks (from 37 to 65% (wt)). The copolymers imide blocks on the T_g and T_m values relative content increasing effect was traced, which is associated with the phase separation of hard imide and flexible polyester blocks in the systems studied.

Abstract: This paper investigates the damage behavior of thermoset and thermoplastic fiber-reinforced composites. The specimens were subjected to low-velocity impacts (LVI) to produce barely visible impact damages (BVID). To compare the dependency of the matrix system and the laminate lay-up on the impact damage, four test series were set up. Therefore, laminates with an epoxy (EP) and a polyether ether ketone (PEEK) matrix in a quasi-isotropic (QI) [+45/0/-45/90]_2s and an orthotropic (OT) fiber lay-up [0/90]_4s were manufactured. To eliminate the influence of variant fiber systems, the thermoplastic tape and the thermoset prepreg contain similar carbon fibers (CF). After impact testing with three different impact energies, inner damages were investigated by using ultrasonic analyses. To get a deeper understanding of the interior damage mechanisms, cross sections of the damaged areas were examined via reflected light microscopy. By using these destructive and non-destructive test methods, significant differences in the damage behavior of composites with thermoplastic and thermoset matrix systems were identified for both laminate lay-ups.