Over the past few decades, masterbatch production has been increasing year by year. Pigments are used primarily in masterbatches because of their ability to impart colour or opacity to a matrix. The effectiveness of pigments depends not only on their intrinsic ability to absorb or scatter light, but also, importantly, on the dispersiblity and distribution of the pigments that can be achieved in plastics. Nowadays, stringent environmental as well as excellent quality controls are making inevitable the use of non‐dusty monoconcentrated predispersed pigments for the production of masterbatches for the colouring of plastics. Commercially, for the most part, two types of monoconcentrated predispersed pigments are being used for the colouring of thermoplastic masterbatches. These are polymer‐ and wax‐based predispersed pigments. This study has been undertaken to provide a comparison of the colouring properties of polymer‐ and wax‐based monoconcentrated predispersed pigments. Four commercially used organic pigments have been selected. Both types of monoconcentrate predispersed pigments have been developed on a co‐rotating twin‐screw compounding extruder with a length/diameter ratio of 44. A detailed analysis on the comparison of the colouring properties is presented. Results indicate that good colour properties are achieved when operating conditions are optimised.

The performance of the composites is determined on the basis of the interface bonding of the

Polyvinyl chloride (PVC) is one of the most commonly used thermoplastic materials in cables and wires for electrical insulation. PVC has very good-to-excellent electrical and mechanical properties which make it suitable for use as an electrical insulating material in many domestic and industrial electrical insulation applications. Mica-filled PVC composites may become the cost-effective substitutes for other types of cable and wire compositions with their improved properties. In this study, water ground mica samples of different particle sizes, surface areas, and concentrations were used for fabrication of PVC composites with and without its surface treatment. Haake Rheochord 9000 compounder using roller-type blades was used for the fabrication of different PVC test composites. Melt-compounded composite was compression molded for making sheets. Mechanical and electrical properties were determined using these test sheets. Mechanical properties such as Young’s modulus, stiffness, and shore hardness increased with increase in mica concentration, whereas tensile strength and elongation at break values are found to decrease with increase in mica concentration. Dielectric properties also increase with mica loading. Morphological studies revealed that there was good adhesion and dispersion of the mica in the PVC composite. It was revealed that mechanical and electrical properties were marginally improved with the use of silane-treated mica.

In the frame of the circular economy, welding of Ni-based superalloys has gained increasing importance when applied, for instance, to repairing highly expensive components widely used in strategical sectors, such as the defense and aerospace industries. However, correct process parameters avoiding metallurgical defects and premature failures need to be known. To reach this goal, Inconel 625 butt-welded joints were produced by CO2 laser beam welding and different combinations of process parameters. The experimental investigation was carried out with three parameters in two levels with an L4 orthogonal array. Laser power, welding speed, and shielding gas flow rate were varied, and the results were reported in terms of mechanical properties, such as microhardness, tensile strength, distortion, residual stress, and weld bead geometry, and metallurgy. At a lower welding speed of 1 m/min, the full penetration was observed for 3.0 kW and 3.3 kW laser powers. However, sound welds (porosity-free) were produced with a laser power of 3.3 kW. Overall, the obtained full-penetration specimens showed a tensile strength comparable with that of the parent material with residual stresses and distortions increasing with the increase in heat input.

Polyvinyl chloride (PVC) of different grades is the second most commonly used polymer for fabrication of electric cables and wires after polyethylene. Cables of domestic and industrial use of various capacities are fabricated using different compounds of PVC. Mica is useful particulate filler extensively used to enhance the performance of many polymeric materials. It surface resistance and arc resistance improving its mechanical properties. In the present research work mica filled PVC composites of different concentrations were prepared using untreated and surface treated water ground mica of different particle size. Mica filled PVC composites were compounded for various compositions and test samples were prepared using compression moulding process. These samples were tested for electrical insulation and mechanical properties. The results shows enhancement in dielectric properties with improvement in Young's modulus, stiffness, reduction in elongation at break and slight increase in shore D hardness of composites. Scanning electron microscopy was used to test the morphology of the samples which has shown proper distributions and adhesion of the filler mica in PVC matrix. There was some effect of surface treatment of mica on its mechanical and dielectric properties of the composite.