Papers by Keyword: Mold

Abstract: The article considers the main points for choosing lubricants, taking into account the specifics of the injection molding process. The main drawbacks of modern lubricant compositions are identified, and based on them, the main requirements for lubricants for injection molding are determined. The most critical parameters of lubricants are specified, depending on the melt to be filled. The methods of applying lubricants are considered, and the most optimal ones are selected.

Abstract: Over the course of the last decade 3D printing has become a more established technology in terms of prototype development (rapid prototyping). The current effort is focused on transferring this knowhow into a product driven approach in order to manufacture even small batch sizes more economic. In terms of this work, this idea is adapted for the development of injection molds (rapid manufacturing). Hereby, a hardened polymer is used to create a forming cavity instead of tool-steel. In order to fulfil the mechanical process requirements of micro injection molding such as form stability under temperature and pressure this cavity is nevertheless integrated into a metal housing. A first set of experiments has been carried out using this develop mold to verify the capabilities of the developed prototype as well as molding process. Based on these first results, an optimization is carried out to improve the next iteration of this molding tool.

Abstract: The complex nature of metal casting process brings about a need to simulate it before undertaken in a foundry. Casting simulations provide insights on flow of molten metal within the mold, solidification sequence, nature and location of defects etc. Moreover, mold design can be optimized to minimize defects without undergoing physical trials-and-errors as previously practiced in traditional metal casting. This study is based on casting an ASTM A216 WCB steel spring flap for automotive suspension system using a simulation based optimized mold design. The initial and optimized mold designs are simulated in MAGMASoft for mold filling, solidification, stress distribution and defects prediction. The results of simulations and actual castings are found to be in good agreement. It is concluded that simulations are accurate in modeling casting process and in predicting defects followed by their minimization through mold design optimization. The use of auxiliary components in a carefully designed mold can lead to a nearly defect-free and high quality cast product.

Abstract: Relaxation-compression resin transfer molding under magnetic field is a new variant of VARTM (“vacuum assisted resin transfer molding”) process, which uses a flexible magnetic membrane controlled by a magnetic force, in order to govern the relaxation and compression phases by changing the permeability of the fabric preform. Thus permits to the resin to enter easily into the mold and to increase the resin impregnation velocity and the fiber volume fraction. This innovation is based on the application of the TRIZ theory (“the theory of inventive problem solving”), which allows us to answer to the shortcomings and the conflict links exist inside the VARTM processes. The objective of this paper is to present this new process and to study the effect of the current intensity and the separated gap between the flexible magnetic membrane and solenoid on the permeability of the preform.

Abstract: Nitrogen ions with an energy of 200keV were used for the investigation of the interlayer effects of nitrogen implantation in the TiN/N₂-film synthesis on the NAK80 steel. The nitrogen ion plasmas formed a broad ion mixing area at the interface between TiN film and NAK80 substrate. The measured hardness indicates the well mixing of TiN film into the NAK80 substrate, which may have an effect on increasing the adhesion of the deposited film. The chemical components and micro-hardness of the filmed surface were measured. The micro-hardness of Rockwell C-scale (HRC) was increased from 40 to 61 after the films of TiN/N₂ were synthesized on the NAK80 substrate, the increased micro-hardness is attributed to the metallurgical phase change and formation of amorphous crystal due to the nitrogen implantation.

Abstract: The use of metal-polymers in the manufacture of mold-forming parts allows for the significant reduction in price and time used in manufacturing of parts. Using data on the thermal conductivity of metal-polymers in calculations of the cooling system of molds allows calculating the optimal cycle of obtaining the product. The authors propose a method of determining the coefficient of heat transfer of metal-polymers based on a die matrix, filled with aluminum. The chosen equipment or measuring tool by them, allows determining the heat transfer coefficient of the material in use. The values of the coefficient of heat transfer of the material in question, obtained in the course of the research can be use in different databases of applications used for modeling production by injection molding. The described method of determining the coefficient of heat transfer may be repeated for samples of metal-polymers.

Abstract: Injection molding is one of the most extended plastic processing technologies. Delivery of polymer melts into the mold cavity is the most important stage of the injection molding process. This paper shows the influence of mold cavity surface roughness and technological parameters on the flow length of thermoplastic elastomers and rubber into mold cavity. The fluidity of polymers is affected by many parameters (mold design, melt temperature, injection rate and pressures) and by the flow properties of polymers. Evaluation of the data obtained by experiments where the testing conditions were widely changed shows that quality of the cavity surface does not affect the length of flow.

Abstract: Laser surface hardening, is a process in which a shaped laser beam is scanned across the surface to produce a hard and wear-resistant surface on components. Compared with the conventional surface hardening process, the laser heat treatment offers a number of attractive characteristics such as minimal part distortion, self-quenching and the need for less finishing work. The challenge of laser hardening is the uneven surfaces found in molds such as those with sharp edges or holes. In these cases, due to the differences in the surrounding volume of the material, overheating problems often appear leading to unacceptable treatment results. The purpose of this paper is to present the new technology, “raio” developed by Talens System for laser hardening process. This technology is able to adapt to geometrical singularities of the components to be treated, ensuring the dimensions of the hardened area and hardness values are compliant with the requirements. The main features of the technology for laser hardening are validated on a set of samples of 1.2738 steel with representative discontinuities of molds. Mechanical and microstructural characterizations of the hardened cross sections confirm the advantages of the raio technology in regard to the quality compliance of the laser hardening process. Furthermore, raio offers the same advantages for other laser processes, like softening of critical area or laser cladding for repairing of damaged components.

Abstract: The energy materials such as titania (TiO₂) and alumina (Al₂O₃) are the environmental friendly materials. In this paper the nanostructure of high surface area titania and alumina are fabricated by anodization process and assistance in electrochemical mold. In general, academic or research institutes can simply control the required experimental conditions in a small sample; however, it’s difficult to control the stable parameters in a large surface and a large number of nanostructural products in the industry production. In order to solve the problems of unstable current density and temperature we have designed a cooling functional electrochemical mold which can improve the nanostructural quality of energy materials during a large number production. The electrochemical mold is used for a local surface treatment at an isothermal temperature controlling. The mold limits sample for a specific treated area and current density in the electrolyte. The mold can be used for the assistance of electrolysis, electro-polishing, electro-deposition, anodization, etching, chemical deposition, pickling, and caustic processes. The mold structure includes fixture group, water-cooling electrode group, and electrode conductive group.

Abstract: ANSYS finite element analysis theory was employed to simulate the process of biomass compression molding. The analysis and calculation like element selection, material attribute setting, mesh generation, contact pair establishment, load and constrain applying and solver setting were finished. The results shows that: The biomass produced in this mold contains heterogeneous density where the density in one end is higher than the other end; There is still shear stress at the section of molding fuel, which cannot be removed after molding; moreover, along with the natural expansion of biomass material after compression, crack is likely to appear on the surface of biomass molding fuel. With respect to mold, it is obvious that, the stress of top of compression material to mold is the largest, which is caused by the concentrated stress on mold generated by joint action of friction between raw material and mold, larger extrusion force at top and deformation force of raw material resisting compression. Thus, the abrasion of this mold at this part is the largest.