Sachin D. Waigaonkar

Owing to its promising physical, chemical, and optical properties, glass is the most widely used material in sophisticated micro-electro-mechanical systems (MEMS) devices. These devices are finding large number of applications in the fields of medical electronics, biotechnology, energy, automobiles, aerospace, etc. While manufacturing MEMS devices, micro-holes are needed to be produced in glass with high levels of accuracy. Micro-drilling in glass using the electrochemical discharge drilling (ECDD) method is an emerging technique. Enhancing the material removal rate (MRR) and lowering the entrance hole overcut in ECDD are the major challenges during this process. To address this problem, significant attention is focused on blending two or more techniques known as hybridized methods to improve the quality of the ECDD process. In the present study, a combination of magnetic flux density (MFD) and high-speed tool rotation was employed during the ECDD process for the glass. Additionally, the effect of the process variable viz. the voltage, tool rotation speed, and feed rate of the MFD around the workpiece was analyzed. Finite element analysis was employed to obtain the optimal MFD over the workpiece. For different voltages, tool rotation speeds, and feed rates; the performance analysis of MRR and entrance hole overcut were compared in the absence and presence of magnetic field-assisted high-speed ECDD.

In this study, the short fiber jute-polypropylene (PP) composite simulation was attempted using extended finite element technique. The simulation parameters required for the study were determined from the experimental findings. Special fixtures were developed to determine tensile strength of jute fiber bundle and the interfacial strength of jute fiber-PP matrix. The developed model has been used to study the influence of aspect ratio, fiber volume fraction, and fiber orientation on the modulus of short jute fiber-PP composite. The predicted values of modulus from simulation model were observed to be in agreement with Halpin-Tsai model within the error range of 0.56 to 1.02%. The model forms a base to study the progressive damage occurring in natural fiber composites.

This paper deals with investigations of rotational molding of LLDPE – Fumed Silica (FS) nano composites. The investigations were conducted at an industrial scale using a three arm biaxial rotational molding machine by carefully monitoring the Internal Air Temperature (IAT) within the mold. The effect of 4% FS on powder flow quality (dry flow and bulk density), melt flow quality (Melt Flow Index (MFI), static mechanical properties (tensile strength, modulus, toughness, flexural strength and impact strength) as well as dynamic mechanical properties (storage and loss modulus), along with creep and relaxation were investigated. Morphological studies were conducted to correlate the above findings with the dispersion of the nano particles within the LLDPE matrix.

Rotationally moldable linear low density polyethylene (LLDPE) is one of the most popular materials used for rotational molding. Yet, incorporation of additives is necessary to improve the mechanical, visco‐elastic, thermal as well as melt flow properties of LLDPE. In this article, the influence of fumed silica (FS) nanoparticles on the mechanical properties viz. tensile, flexural, and impact strengths of rotationally moldable LLDPE is investigated. The microstructural studies using SEM were conducted to study the dispersion of FS in LLDPE and correlated with the mechanical properties of the nanocomposites. Dynamic mechanical analysis (DMA) were also carried out to find the time–temperature dependent mechanical properties viz. storage modulus (E'), loss modulus (E”), and tan delta between 1 and 8 wt% of FS. DMA studies were extended to perform accelerated stepped isothermal creep studies to find out the influence of FS in creep strains. POLYM. COMPOS., 38:421–430, 2017. © 2015 Society of Plastics Engineers