Effects of formulation and processing parameters on the morphology of extruded polypropylene-(waste ground rubber tire powder) foams

• Published in: Journal of vinyl & additive technology 2009-12, Vol.15 (4), p.266-274
• Main Authors: Xin, Zhen Xiang, Zhang, Zhen Xiu, Pal, Kaushik, Lu, Bing Xue, Deng, Xu, Lee, Sung Hyo, Kim, Jin Kuk
• Format: Article
• Language: English
• Subjects: Applied sciences; Blowing agents; Cellular; Exact sciences and technology; Foaming; Foams; Forms of application and semi-finished materials; Grounds; Morphology; Polymer industry, paints, wood; Polypropylenes; Process parameters; Screws; Technology of polymers; Waste treatment
• ISSN: 1083-5601; 1548-0585
• DOI: 10.1002/vnl.20191

This paper presents an experimental study of the foaming behavior of polypropylene (PP)/(waste ground rubber tire powder) (WGRT) blends when using a chemical blowing agent in an extrusion foaming process. The effects of formulations (i.e., WGRT content, blowing agent content, compatibilizer) and the processing parameters (i.e., die temperature, screw speed) on the void fraction, average cell size, cell density, and cell morphology of the PP/WGRT foams were investigated. The blowing agent loading affected the cell structure of the foams and the average cell size, and the void fraction increased with increasing blowing agent loading. Both increasing the screw speed and decreasing the die temperature could establish a high pressure drop in the extruder die, and these were beneficial to the foaming extrusion. J. VINYL ADDIT. TECHNOL., 2009. © 2009 Society of Plastics Engineers