عنوان مقاله [English]
This research has been conducted with the view of the effect of various polymeric processing aids (PPA) on the stick-slip phenomenon in polyethylene compounds. In the extrusion process of thermoplastic polymers, such as polyethylene, for proper and efficient products like wire coatings, pipes, bottles, and films, it is desirable that the final products, gain a smooth surfaces and be polished. In the industry, it is also necessary that the rate of extrusion process is as high as possible, dislike the pressure of this process is as low as possible, so that it can be used for the most part from process machines and thus reduce process costs so much as practical. In this study, MBM and MBR masterbatches (containing 35-40% carbon black) were added to high density polyethylene powder (PE100) and the effect of these masterbatches on the reduction of viscoelastic phenomenon was confirmed. In the next step, three types of PPA with commercial names of Viton, Fx and Daikin with concentrations of 50, 100 and 150 ppm were added to the PE100MBR and PE100MBM compounds to reduce the melt fracture of the samples. The capillary rheometry test determined the quantity changes in the stick-slip phenomenon. The microscopy test also showed qualitatively the changes that occurred in the extrudates. The torque meter test also determined the effect of the PPA on the ampere and the energy consumed by the extruder. Finally, samples were produced with these features due to the importance of reducing energy in the process as well as improving the quality of the extrudates. Depending on the structure of the fluoroelastomer and hyper branch polymers, it has been found that adding these kind of materials has improved processability, and finally the appearance of the product is smoother and polished.