Papers by Keyword: Polymer

Abstract: The production of Molded Interconnect Devices (MIDs) may be achieved through different processes. In this work Centro Ricerche Plast-optica (CRP) has chosen to evaluate, implement and assess Laser Direct Structuring (LDS) and In Mold Labeling (IML) technologies for the production of MIDs. Both alternative methods have been analyzed starting with a 2D component, mainly used for implementation and optimization of the process, and finally a more complex 3D component, that has been designed and produced. The first phase of the activity regards the production of several conductor patterns on planar substrates dedicated to evaluate properties as conductors resistance, adhesion, SMD components solderability, wire bondability of bare LED dice etc. In the case of IML, a flexible circuit has been over-molded during the production of the component by injection molding process: planar parts have been tested also in terms of adhesion of flexible circuit to the injected polymer. The second phase of the activity concerns the production of 3D circuits. Both technologies have been implemented in order to select to materials, process conditions and parameters, design rules and to verify the reliability in the automotive severe conditions. Exploitation of technologies have been performed on an automotive rear lamp. A prototype has been produced in LDS technology and allowed to define the conditions that make economically affordable this solution. Differently, the IML technology allowed to produce a completely new device by embedding a planar electronic circuits into the plastic material.

Abstract: The idea of incrementally forming sheet metal with a single point tool, called ‘dieless forming’, was patented by Leszak [1] well before it was technically feasible. There have been many studies, which have lead to the present situation [2-9]. The new processes are attractive because manufacturing sheet metal can be accomplished by any facility having a three-axis cnc mill. Sheet metal spif is an innovative, flexible sheet metal-forming technology that uses principles of layered manufacturing. It transforms the complicated geometry information into a series of parameter of two-dimensional layers and then the plastic deformation is carried out layer-by-layer through the computer numerically controlled. The basic principle of spif (Fig. 1) is that the forming tool moves around the outline of the part along the predefined tool path and extrudes the sheet metal point by point so that the local plastic deformations occur incrementally [8, 10]. The forming tool paths have a great effect on the surface quality, forming time and dimensional accuracy. Although the movement mode of the forming tool is similar to one of the cutters in the cnc milling machine, the forming process based on the plastic deformation and milling process is totally different, so the requirements for the tool paths are different. As a result, there are some specific characteristics which should be considered in forming tool path generation. The goal of this paper is to evaluate the possibility of producing low-cost polymer sheet components by means of spif. Three different thermoplastic materials were incrementally formed on a conventional cnc milling machine. Experiments are conducted to determine the formability, failure modes and significant process parameters. Even though considerable amount of research work has been done in the field, these aspects are not completely defined and only limited number of materials has been tested.

Abstract: In this paper electromagnetic properties of composite materials based on polymethylmethacrylate and multiwall carbon nanotubes (MWCNTs) are investigated. Carbon nanotubes are received with application of various types of catalysts and have various structural parameters. Calculation of dielectric permeability of the synthesised materials is carried out. Dependence of electromagnetic properties of composite materials on concentration and structure used multilayer carbon nanotubes is shown.

Abstract: The paper presents the results of experimental investigation of formation microstructure and properties of ultra high molecular weight polyethylene (UHMW-PE), modified by ceramics А1₂О₃ particles by different particle size and method of obtaining.

Abstract: This article provides the results of the study of the strain-stress state of two corrugated shell structures. Geometric modeling was conducted in “Autodesk Inventor” system. Corrugated shell structures were studied with the help of engineering analysis systems MSC.Patran and MSC.Marc. As a result of the study an optimal type of corrugated shell structure was chosen.

Abstract: The use of polymeric matrices with different crystalline degree values for the design of polymer compounds for tribotechnical purposes is demonstrated. The wear resistance of the provided material in question trends significantly in favor of compounds with greater crystalline degree values. Considering the macrolevel data, the level of the sampled materials carry almost equal effective stress-strain properties. Therefore this difference may be associated with local material properties which influence the rearrangement of stress-strain state parameters in polymeric matrices with changing crystalline degree values.

Abstract: Weak gel was sythysized by twin-tail hydrophobically associating polymer P(AM/ DiC6AM/NaAA) crosslinked with water-soluble phenolic resin. Apparent viscosity of week gel increases with the increasing of polymer concentration and the increasing of phenolic resin. The crosslinking reaction is influenced by salt. Apparent viscosity of week gel firstly increased and then decreased with increasing salt concentration. Weak gel has shear thinning property. But apparent viscosity of weak get is recoverable after shear.

Abstract: Brief introduction of research progresses of hydrophobically associating water soluble polymer, as well as a synthesis method of a hydrophobically associating water-soluble polymer P (AM/KAA/MAHB). Meanwhile the molecular structure is characterized, and the viscosity behavior of the ionic hydrophobic-associating polymer solution is analyzed. The influences of polymer concentration, temperature, shear rate and water salinity of the saline solution on apparent viscosity are discussed. The critical associating concentration of polymer in salt solutions and salt thickening effect are also studied. The results show that the polymer possesses obvious temperature resistance and salt tolerance compared with partially hydrolyzed polyacrylamide polymer.

Abstract: This research paper deals with behavior of recycled material at higher temperature. Assessment of recycled material influence takes place on four kinds of thermoplastic materials, which are always high-heat polycarbonate (PC-HT) with different amount of recycled material (pure polycarbonate, polycarbonate with twenty percent of recycled material, polycarbonate with thirty percent of recycled material and hundred percent of recycled polycarbonate). Specimens were prepared by the mostly used technology for production products, which is injection molding. Each kind of material is one by one loaded by high temperature 110°C and consequently tested. This temperature was chosen because we encounter products made with recycled material additive, which can be used at elevated temperatures. To determine behavior of recycled material at this high temperature, one basic mechanic material tests is used. This test is normalized compression test.

Abstract: This article studies creep of a radiation cross linked HDPE polymer material. It describes a process of production of test samples, which are then radiation cross linked in six doses of radiation. These samples are tested for creep resistance at elevated temperatures on a machine of custom design that will provide sufficient information about a suitable use for the material and to find an optimal dose to achieve minimal stretching. [1-3]