Study on the Influence of the Injection Pressure on Certain Mechanical Features of Acrylonitril Butadiene Styrene (ABS), of Polypropylene (PP), and of Polyethersulfone (PES), by Determining Methods of Stress Resistance

摘要

The paper presents the influence of the injection pressure during the processing of the acrylonitrile butadiene styrene (ABS), the polypropylene (PP), and polyethersulfone (PES) on certain mechanical features when obtaining technical items made for various industries. The ABS samples were obtained at the following injection pressures: 400 bar, 500 bar, 600 bar, 700 bar, and 800 bar. The PP samples were obtained at the following injection pressures: 200 bar, 300 bar, 400 bar, 500 bar, and 600, and the PES samples were obtained at the following injection pressures: 650 bar, 750 bar, 850 bar, 950 bar, and 1050 bar. Determining the mechanical properties was made using determining methods of tensile properties of Izod impact test, and of Shore Durometer hardness test. It was observed in the case of the three analysed polymers that increasing the injection pressure in the case of polypropylene (PP) leads to a slight increase in hardness, whereas in the case of the acrylonitrile butadiene styrene (ABS) and polyethersulfone (PES), an increase in the injection pressure leads to a decrease in the hardness of the two materials. The Izod shock resistance for the three tested materials decreases along with the increase of the injection pressure. The tensile strength at break by traction is influenced by the injection pressure. An increase in the injection pressure in the case of ABS and PP leads to an increase in the resistance of the tensile strength at break by traction whereas in the case of PES, an increase in the injection pressure leads to a decrease in the tensile strength at break by traction.