A single-step, extrusion-based process to depolymerize poly(ethylene terephthalate) (PET) is being investigated. The depolymeriza tion is effected by reacting ethylene glycol (EG) with the high molecular weight polymer (glycolysis). The ethylene glycol causes chain scission by attacking the ester linkages along the polymer backbone. The objective is to recover purified low molecular weight olig...

A central composite rotatable design with four independent variables viz. blend ratio (broken rice flour and cowpea flour): 90:10–70:30, moisture content (10–18% wet basis), barrel temperature (110–150 °C), screw speed (280–360 rpm) were varied in the development of ready-to-eat snacks using a twin extruder for broken rice–cowpea product. The effects on specific mechanical energy, water absorpt...

A closed loop controller is designed for regulation of the volumetric output flow in a polymer extruder. To this aim, temperature and pressure at the machine output must be controlled on the basis of real time measurements. It has been verified that temperature and pressure regulations can be achieved by solving two disjoint control problems. The temperature controller acts on the heat delivere...

Co-rotating twin-screw extruders are widely used by polymer materials producers and compounders due to a number of interesting constructive and functional features. In fact, a broad range of polymer systems can be prepared / processed by adjusting adequately the operating conditions (output, screw speed and barrel temperature profile) and the screws geometry/configuration. This work presents a ...