The influence of screw configuration and screw speed of co-rotating twin screw extruder on the properties of products obtained by thermomechanical reclaiming of ground tire rubber

De-vulcanization of rubber has been shown to be a viable process to reuse this valuable material. The purpose of the de-vulcanization is to release the crosslinked nature of the highly elastic tire rubber granulate. For present day passenger car tires containing the synthetic rubbers Styrene-Butadiene Rubber (SBR) and Butadiene Rubber (BR) and a high amount of silica as reinforcing filler, producing high quality devulcanizate is a major challenge. In previous research a thermo-chemical mechanical approach was developed, using a twin-screw extruder and diphenyldisulfide (DPDS) as de-vulcanization agent.The screw configuration was designed for low shear in order to protect the polymers from chain scission, or uncontrolled spontaneuous recombination which is the largest problem involved in de-vulcanization of passenger car tire rubber. Because of disadvantages of DPDS for commercial use, 2-2′-dibenzamidodiphenyldisulfide (DBD) was used in the present study. Due to its high melting point of 140 °C the twin-screw extruder process needed to be redesigned. Subsequent milling of the devulcanizate at 60 °C with a narrow gap-width between the mill rolls greatly improved the quality of the devulcanizate in terms of coherence and tensile properties after renewed vulcanization. As the composition of passenger car tire granulate is very complex, the usefulness of the Horikx-Verbruggen analysis as optimization parameter for the de-vulcanization process was limited. Instead, stress-strain properties of re-vulcanized de-vulcanizates were used. The capacity of the twin-screw extruder was limited by the required residence time, implying a low screw speed. A best tensile strength of 8 MPa at a strain at break of 160% of the unblended renewed vulcanizate was found under optimal conditions.

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Application of a New Twin-Screw Extruder to the Waste Tire Regeneration

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.561.326 ◽

2013 ◽

Vol 561 ◽

pp. 326-330

Author(s):

Lei Guo ◽

Qing Kun Liu ◽

Chuan Sheng Wang

Keyword(s):

Mechanical Properties ◽

Reaction Temperature ◽

Physical And Mechanical Properties ◽

Crumb Rubber ◽

Twin Screw Extruder ◽

Screw Extruder ◽

Screw Speed ◽

Waste Tire ◽

Twin Screw ◽

Regeneration Effect

This paper uses a new twin-screw extruder for regeneration of waste tire crumb rubber, discusses the influence of screw speed and reaction temperature on the physical and mechanical properties of reclaimed rubber. Experimental results show that different screw speed and reaction temperature has a great impact on the physical and mechanical properties of the reclaimed rubber. When controls screw speed in the 60 ~ 90 r / min, reaction temperature at 170 to 210°C,the regeneration effect is the best. At this time, the physical and mechanical properties of reclaimed rubber, such as tensile strength, tear strength and elongation at break rate, is the best.

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Optimasi Proses Pembuatan Mi Sorgum Dengan Menggunakan Ekstruder Ulir Ganda (Optimization of Sorghum Noodle Processing with Twin Screw Extruder)

Jurnal Sains Terapan ◽

10.29244/jstsv.3.1.1-7 ◽

1970 ◽

Vol 3 (1) ◽

pp. 1-7

Author(s):

Tjahja Muhandri ◽

Subarna Subarna ◽

Ivan Mustakim

Keyword(s):

Response Surface Methodology ◽

Optimum Condition ◽

Processing Condition ◽

Cooking Loss ◽

Optimum Process ◽

Twin Screw Extruder ◽

Screw Extruder ◽

Screw Speed ◽

Twin Screw ◽

Optimum Processing Condition

The objective of this research was to optimize the sorghum noodle processing with two variables i.e. extruder temperature (80, 85, 90oC) and screw speed (10, 15, 20 Hz). The optimum process was chosen by using Response Surface Methodology (RSM), based on 2 parameters, i.e. cooking loss and elongation. The result of this research showed that the optimum processing condition with desirability of 0.736, was resulted from the combination of the extruder temperature of 85oC and screw speed of 20 Hz. The verification showed that the sorghum noodles from this optimum condition had cooking loss of 11.87 %, and elongation of 234.84. Keywords: noodle, sorghum, optimization, twin screw extruder, RSM

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