Use of response surface methodology in characterization of properties of recycled high density polyethylene/ground tire rubber compositions (in English)
Polimery 2014, No 6, 495
The results of an investigation of the process of electrostatic separation of binary polymeric blends with different content (10, 20, 30, 40, 50, 60, 70, 80, and 90 wt %) of acrylonitrile-butadiene-styrene terpolymer (ABS) and poly(methyl methacrylate) (PMMA) are presented. The separation was carried out by using a home-made prototype of electrostatic cylindrical separator. It was found that the effects of the tribocharging in fluidized bed depended on the process duration. A maximum value of the electric potential (over 22 kV) of the blend containing 50/50 wt % of ABS and PMMA was attained after ca. 20 s of the electrization. Instead, during the mechanical tribocharging, an electric potential increased with the rise of the rotational speed of a stirrer and reached a value of ca. 18 kV. The blend separation was performed in an electrostatic field arising between a high-voltage elliptic electrode and cylindrical ground electrode rotating at a rate of 30 rpm. The dc voltage between the electrodes was 20 kV and the electrostatic field intensity did not exceed 4 kV/cm. It was found that the effects of the separation process, i.e., purity of the particular fractions and yield of the ABS and PMMA recovery, depended on both the tribocharging effects and contents of the individual blend components. A better separation was achieved for the more balanced compositions. The investigations also indicated that the separation of blends containing 20—70 wt % ABS (30—80 wt % PMMA) may result in a purity of the particular fractions above 95 wt % and recovery yield above 97 wt %. Further increase in the purity and yield is possible by application of a multi-step separation.