Waste Plastic Extruder: Literature Review

The following literature review has been conducted as part of the Waste plastic extruder for Mech 461.

Searches
Waste plastic extrusion RepRap Fab@home Open Source Rapid Prototyping

Open Source Rapid Prototype Technology and Potential Applications
==== J. M Pearce, C. Morris Blair, K. J. Laciak, R. Andrews, A. Nosrat and I. Zelenika-Zovko, “3-D Printing of Open Source Appropriate Technologies for Self-Directed Sustainable Development”, Journal of Sustainable Development 3(4), pp. 17-29 (2010). http://www.ccsenet.org/journal/index.php/jsd/article/view/6984 ====


 * Discusses evolution of Open Source 3D (OS3D) rapid prototyping technology.
 * Expresses potential uses of OS3D as a sustainable development tool, along with increased internet access and material availability.
 * Summary of potential applications and limiting factors on utility
 * Identifies future areas of research to improve OS3D technologies, make them more applicable in a developing world context.
 * Specifically, relating to this project, states that research is needed in creating feedstock from locally available materials.

Fab@home Project, www.fabathome.org.

 * Similar project to RepRap and RapMan.
 * Developed at Cornell University by Hod Lipson and Evan Malone.
 * Uses open source developed hardware and software. Software programs have been specifically developed for the [mailto:Fab@home Fab@home] but are open source.
 * Extrusion uses a syringe/piston based system – can handle diverse materials.

S.P. Ladamy, K.C. So, “Optimal Recycling of Waste Materials in a Plastic Extrusion Production Process”. European Journal of Operational Research, 79(1994), pg 13-24.

 * Recycling process overview.
 * Recyled plastic mixed with virgin material to retain engineering properties
 * Less virgin material in plastic each cycle
 * Authors attempt to determine optimal number of cycles of mixing reclaimed and virgin material
 * Based on factors such as sale price, value of recovered waste material, raw material cost, production, etc.
 * Numerical model developed to determine optimum cycling.

Relevance:


 * Some useful insights into engineering properties of recycled plastics.
 * Virgin material mixing may be utilized.

R. Hettema, J. Pasman, L.B.P.M Janssen, “Reactive Extrusion of Recycled Bottle Waste Materials”, Polymer Engineering and Science, April 2002, Vol. 42, No. 4.

 * States challenges of plastic recycling
 * mixing waste streams (ie. HDPE and PP) results in undesirable engineering properties.
 * hard to recreate properties of virgin material
 * Authors conducted experiments with reactive extrusion (chemicals added during process)
 * peroxides added during extrusion process.
 * found to be beneficial in improving properties such as toughness
 * Extrusion settings also tested for effects on material properties.
 * mass flow rate, screw speed and termperature tested.
 * linkage found between these parameters and % elongation, Young's modulus and yield strength.

Relevance


 * Reactive extrusion could be explored to improve properties of expanded materials. Need to ensure such chemicals are domestically available in a development setting.
 * Extrusion parameters will have to be tested to determine optimal conditions for quality feedstock production.

O. Vongeheur, “ Fundamentals of Extrusion”, Candy Industry. January 2008.

 * Basic outline of extrusion processes
 * describes major steps in extrusion and examines three methods – screw, piston and roller
 * Originally written for Candy Industry – therefore may not apply to RepRap. But does describe mechanical processes for plastic
 * Note also that RepRap extruders have been designed to extrude paste, as has the piston system of Fab@home.

Links

 * Appropedia page that this page was transwikified from
 * Homemade Plastic Extrusion System