Waste plastic extruder: literature review\Addition Compatibilization of PP\PS Blends by Tailor-Made Copolymers

The following literature review has been originally conducted as part of the Waste plastic extruder for Mech 461. It now supports the Recyclebot project. Please add content.

Addition Compatibilization of PP/PS Blends by Tailor-Made Copolymers[edit | edit source]

M. Diaz, S. Barbosa, and C. Numa, "Addition Compatibilization of PP/PS Blends by Tailor-Made Copolymers," Polymer Engineering and Science, vol. 46, no. 3, pp. 329-336, Mar. 2006.

• Taylor Made Compatibilizer (TMC) is added to PP/PS blend
• benefits - uses small amounts of low cost reactants, process is not affect by secondary reactions that can degrade/modify the blend, allows for optimization of amount/quality of the copolymer formed
• incomplete homogenization of the compatibilizer caused samples to break before the cold drawing-strength zone meaning that the interfacial PP/PS adhesion is lower than the shear stress of the matrix
• TCM concentration doesn't affect yield strength
• % elongation at break highest when TMC concetration (wt %) is between .5 - .75,
• applicable to the recycling of mixed plastics from urban/industrial waste sources.

Combined kinetic analysis of thermal degradation of polymeric materials under any thermal pathway[edit | edit source]

P. E. Sánchez-Jiménez, L. A. Pérez-Maqueda, A. Perejón, and J. M. Criado, "Combined kinetic analysis of thermal degradation of polymeric materials under any thermal pathway," Polymer Degradation and Stability, vol. 94, no. 11, pp. 2079-2085, Nov. 2009.

• experimental curves for the thermal degradation of polytetrafluoroethylene and polythylene under linear heating
• may be useful for determining the impact of long term heating on PE

Molecular Modification and Compatibilization of Collected Polyethylene[edit | edit source]

M. Sjoqvist and A. Boldizar, "Molecular Modification and Compatibilization of Collected Polyethylene," J polym environ, no. 19, pp. 335-340, 2011.

• PE extruded at 200, 300, 350 °C
• 350°C had highest Elastic modulus, 200°C lowest
• adding 5% EPDE ( Ethylene- propylene diene rubber ) to PE w. 5% PP leads to better interfacial adhesion, increased tensile strength

Processing and Characterization of Recycled Poly(ethylene terephthalate) Blendes with Chain Extenders, Thermoplastic Elastomer, and/or Poly(butylele adipate-co-terephthalate)[edit | edit source]

Y. Srithep et al., "Processing and Characterization of Recycled Poly(ethylene terephthalate) Blendes with Chain Extenders, Thermoplastic Elastomer, and/or Poly(butylele adipate-co-terephthalate)," Polymer Engineering and Science, vol. 51, no. 6, p. 1023, 2011.

• recycled PET shows hydrolytic and thermal degradation, reducing molecular weight and viscosity which negativley impacts mechanical properties and moldability
• can add reinforcing fillers and toughening modifiers to help compensate
• chain extenders (CE) increases molecular weight and melt viscosity, diepoxides, diisocyanates,
• adding PBAt (poly(butylene adipate-co-terephthalate)) improves toughness
• adding CE and PBAT doesn't affect melting temp of recycled PET
• RPET + 25%PBAT + 1.3% CE had the highest impact strength of 5.17
• RPET + 1.3% CE had the greatest Ultimate tensile strength and tehnsile modulus (53.2 and 1450.3 respectably)
• heat treating improved all mechanical properties

Processing of Ternary Polymer Blends Based on Polyvinyl Chloride, Thermoplastic Polyester Polyurethane and Polyethylene-Co-Acrylate-Co-CO.[edit | edit source]

M. Modesti, F. Simioni, M. I. Tiberio, M. Veronelli, G. Zinelli, and M. Passudetti, "Processing of Ternary Polymer Blends Based on Polyvinyl Chloride, Thermoplastic Polyester Polyurethane and Polyethylene-Co-Acrylate-Co-CO.," Journal of Elastomers and Plastics, vol. 32, no. 15, 2000.

• mix of PVC (poly(vinyl cholride)), TPU (thermoplastic polyester polyurethane) and ENBACO (polyethylene-co-n butyl acrylate-co-CO) has possible application in footwear industry
• TPU increases abrasion resistance and tensile characteristics, reduces thermal stability
• Increased ENBACO decreases specific gravity, resistance to abrasion, increases flexibility of chains reducing performance at low temps

Extrusion Process and Technology[edit | edit source]

Fundamentals of Extrusion[edit | edit source]

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.

An experimental study on shear stress characteristics of polymers in plasticating single-screw extruders[edit | edit source]

Atakan Altinkaynak, Sam L. Crabtree, Mahesh Gupta, Mark A. Spalding, "An experimental study on shear stress characteristics of polymers in plasticating single-screw extruders" Polymer Engineering and Science, 49(3), p471, 2009.

• ABS resin inside barrel temp 160-130˚C bc. stresses at interface at maximum and provide maximum forwarding forces at barrel wall.
• Barrel zone temp may need to be 210 ˚C for inside to be at 160˚C.
• LDPE 90˚C screw and 130˚C Barrel stress at interface = .24 MPa (screw) and .27 MPa(barrel) = enough to conval LDPE resin
• LDPE resins can be extruded using an exturder w. short melting section

Reactive Extrusion of Recycled Bottle Waste Material[edit | edit source]

Hettema, L.P.B.M Janssen, J. Pasman, "Reactive Extrusion of recycled bottle waste material" Polymer Engineering and Science, 42(4), p665, 2002.

Notes:

• HDPE mixed w. PP / different grades HDPE --> poor mechanical properties
• Increase in PP = increased young's modulus, decreased impact strength and elongation at break, Figure 8
• Processing Conditions - increasing screw speed @ constant thoughput = improved mixing, impact strength and elongation at break decrease, young's modulus increases (single screw extruder)

Plastics Processing Data Handbook[edit | edit source]

Rosato, Dominick (1997). Plastics Processing Data Handbook (2nd Edition).. Springer - Verlag. (Online) [1].

Notes:

• Very comprehensive text on a wide range of plastics processing technologies. Particularly useful sections for the report include:
  • Chapter 1 - Fundamentals - includes material properties, process overviews, general information.
  • Chapter 3 - Extrusion - extrusion processes and technology
  • Chapter 16 - Auxiliary Equipment - includes material and parts handling, other processes.
• Focus is on large industrial applications but background will be usefull.

Volatile Emissions During Thermoplastics Processing - A Review[edit | edit source]

Patel, S. H., and Xanthos, M., 1995,"Volatile Emissions during Thermoplastics processing—a Review", Advances in Polymer Technology, 14(1) pp. 67-77.

Abstract:

Types and amounts of volatiles emitted during thermoplastics processing depend upon the chemical structure of the material and the choice of processing conditions. The identification of volatiles and the development of analytical techniques for measuring their concentration in the workplace are of paramount importance to establish or revise threshold limit values that would minimize exposure to hazardous chemical substances and lead to corrective action. In this review, information related to the types of volatiles emanating from injection molding machines and extruders as well as analytical methods for their measurement was collected, analyzed, and tabulated. Emphasis was placed on the four major commodity plastics, viz., polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), and polystyrene (PS). Although the main emphasis is on emissions during processing, related literature under simulated conditions is also mentioned.

Notes:

• detailed recording of volatiles emitted from various plastics under different temperatures and process.
• recommend exposure limits not included - relevant for health effects of producing feedstock from waste plastic.

Rapid prototyping of electrically conductive components using 3D printing technology[edit | edit source]

J Czyewski et al., "Rapid prototyping of electrically conductive components using 3D printing technology," Journal of Materials Processing Technology 209 (2009): 5281-5285.

• electrically conductive, carbon-black-filled thermoplastic polymer compounds.
• have a volume resistivity of 10^1 -10^3 ohms and a surface resistivity of 10^2 - 10^4 ohms
• steps 1) model made of powder deposited layer-by-layer and bound by inkjet printed liquid binding agent 2) structure impregnated by a hardenable infiltrant (epoxy based resin)
• can be made electrically conductive if an electrically conductive filer to the infiltrate
• using carbon nanofibers - require low concentration and don't affect infiltrant
• surface resistivity below 800 ohms/sq reached with less than 4 weight% of CNF's
• works at a lower weight% if the CNF's are aggregated vs. being well dispersed

Feasibility study on developing productivity and quality improved layered manufacturing method for rapid prototyping/tooling/manufacture[edit | edit source]

Ajantha K. Egodawatta, D. K. Harrison, A. De Silva, G. Haritos, "Feasibility study on developing productivity and quality improved layered manufacturing method for rapid prototyping/tooling/manufacture," Journal of Materials Processing Technology 149 (2004): 604 - 608.

• Rapid prototyping needs to reduce time to market to compete with conventional manufacturing processes (injection moulding)
• Shell assisted layer manufacturing improves quality and productivity
• 1. develops out shell of specific layer of the part
• 2. fill shell with UV curable resin
• 3. repeat until built
• uses a print head of 1536 nozzels
• benefits - faster, can be made smoother
• drawbacks - complicated, need to remove shell, cannot be used for extremely fine applications

Emissions from Processing Thermoplastics[edit | edit source]

Forrest, M. J., Jolly, A. M., Holding, S. R., 1995,"Emissions from Processing Thermoplastics", The Annals of Occupational Hygiene, 39(1) pp. 35-53.

Notes:

• Various processes and materials tested
• all tested levels well below legislated standards.
• extrusion found to have higher fumes than injection moulded. Worker position important.
• Some toxins, (i.e. aldehydes) not tested.

Thermal and Mechanical Degradation During Polymer Extrusion Processing[edit | edit source]

C. Capone, L. Di Landro, F. Inzoli, M. Penco, and L. Sartore, "Thermal and Mechanical Degradation During Polymer Extrusion Processing," Polymer Engineering and Science, vol. 47, no. 11, 2007.

• found that processing with the extruder screw at a higher rpms had little to no effect on the shear viscosity

Existing Waste Plastic Extrusion Technology[edit | edit source]

RecycleBot[edit | edit source]

"RecycleBot," May-June 2010, RecycleBot blog, [online], http://recyclebot.tumblr.com/archive.

Notes:

• student project at Victoria University in Wellington
• hand crank device built to extrude plastic filament.
  • appears fairly successful.
  • no information on MakerBot mounted adaptation.

More information RecycleBot blog

Plastic Extruder for Growing Media[edit | edit source]

Web4Deb, "Plastic extruder for growing media," December 10, 2010. The Adventures of Bigelow Brook Farm blog. 2010

Notes:

• Web4Deb is online avatar. Name to be found.
• developed to extrude HDPE as a growth medium for aquaponics.
• automated system extrudes at 200ft/ hour.
• could be modified to extrude filament.

More information:

The Adventures of Bigelow Brook Farm: Plastic Extruder for Growing Media.

Also: Web4Deb extruder, RepRap wiki

Developing a plastics recycling add-on for the RepRap 3D printer[edit | edit source]

Braanker, G.B., Duwel, J.E.P., Flohil, J.J., & Tokaya, G.E. (2010), "Developing a plastics recycling add-on for RepRap 3D Printer". (Online) Available: http://web.archive.org/web/20200211171744/https://reprapdelft.files.wordpress.com/2010/04/reprap-granule-extruder-tudelft1.pdf (June 30, 2010).

Abstract:

The main theme of this paper is using domestic waste plastic to create new plastic products. A brief research is conducted in the granule-making field. This research functions as the foundation in selecting the right domestic appliance for creating granule of the right size for a small extruder. This had to be done in a way that regular people must be able to copy this process, so this should be as easy as possible. Parallel to this a literature review was conducted to find the right extruder principle for the creation of a mini extruder. A principle was selected and with the help of experts in the field of 3D printing and extruding this principle was evolved to a design. After lots of trial and error this design has been transformed into a working prototype.

With this prototype five tests were conducted. These tests proved to be very valuable in obtaining new insight in problems that still have to be overcome. The most important problems that were faced are getting the right accuracy in the tolerances, heat development in the granule making process and creating a good granule feed flow for the extruder. While trying to solve these problems other point of interest came along. This research can be seen as the starting point of the development of a new kind of domestic extruder.

Notes:

• background review of RepRap project and rapid prototyping technology
• similar goal to this project - conversion of domestic plastic waste to usable feedstock technology.
• blender used to grind plastic - feedstock for granule extruder.
• Some successes
  • able to extrude some material into filament
  • groundwork on background research and granule extruder design
  • prototypes constructed and tested
• further work
  • consistent product of printing quality
  • reduction of wear on screw and extrusion barrel
• further research and alternatives
  • safety concerns with melting of plastics and hot components
  • effectiveness of tapered screw system
• things to consider - lateral extrusion (used by most commercial processes) and automation.

Follow Up: different method for grinding plastic - developing world context.

Other[edit | edit source]

3-D Printing of Open Source Appropriate Technologies[edit | edit source]

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). Full text: [2]

• covers the use of 3D printers and open design to improve self-directed sustainable development.
• a research trajectory is outlined that includes the use of a waste plastic extruder to extend the existing technology to provide complete village-level fabrication of OSATs.

Understanding Open Source Design[edit | edit source]

Richard Doyle, Erick Froede,David Saint John,Richard Devon, Understanding Open Source Design: A White Paper, In the Beginning Was the Noösphere: Community and Collaboration in Open Source Evolution of Technology, ASEE Proceedings, 2010.

Solid Domestic Wastes as a Renewable Resource: European Experience[edit | edit source]

V.S Fridland and I. M. Livshits, "Solid Domestic Wastes as a Renewable Resource: European Experience," Thermal Engineering, vol. 58, no. 1, pp. 79 - 84, 2011.

• in europe - recycling ratio at 50%
• 10% of solid domestic waste is plastic
• only 10% of the total mass of polymeric wastes can be used as primary polymers because polymers can't be mixed due to thermodynamic incompatibility

Public participaton in plastics recycling schemes[edit | edit source]

Seonaidh McDonald and Rob Ball, "Public participaton in plastics recycling schemes," Resources, Conservation, and Recycling, vol. 22, pp. 123-141, 1998.

• Plastics make up 7% of the UK domestic waste stream
• found a lack of differentiation between groups in terms of age, socio-economic group or household size

Assessment of Plastic Waste Generation and its potential recycling of household solid waste in Can Tho City, Vietnam[edit | edit source]

"Nguyen Phuc Thanh, Yasuhiro Matsui, Takeshi Fujiwara "Assessment of plastic waste generation and its potential recycling of household solid waste in Can Tho City, Vietnam" Environ Monit Assess. DOI 10.1007/s10661-010-1490-8"

• 1 month survey of 130 households - ave plastic waste generated/day = 17.24 g/cap/day, 95.6% plastic containers, 45.72% plastic bags

Solid Waste Characterization, Quantification and Management Practices in Developing Countries[edit | edit source]

Al-Khatib, I. A., Monou, M., Abu Zahra, A. S. F., 2010, "Solid Waste Characterization, Quantification and Management Practices in Developing Countries. A Case Study: Nablus District – Palestine," Journal of Environmental Management, 91(5) pp. 1131-1138

Available online [3]

Abstract:

Solid waste management (SWM) is one of the most challenging issues faced by developing countries that suffer from serious pollution problems caused by the generation of large waste quantities. This paper presents the case study of SWM in the Nablus district – Palestine. Surveys for household residents' and SWM program operators, field investigations, on-site waste measurements and characterizations were conducted. Per capita waste generation rates varied between different localities although trends were similar. Overall, the majority of waste was organic (65.1% by weight), suggesting a strong resource recovery potential in terms of animal feed or compost. Recyclable waste (plastic, paper and card) made up 16.7% by weight the waste composition suggesting an incentive to introduce source separation. Household attitudes complemented the waste characterization study, revealing the main problems faced. SWM operators quoted on the current status, highlighting problems with disposing in unsanitary landfills, ineffective solid waste fees system, increasing solid waste quantities and lacking equipment and experienced personnel. To enhance sustainable SWM, public awareness, funding, expertise, equipment and facilities and other provisions currently lacking or inappropriate must be provided.

Notes:

• found significant percentage (7.6%) of waste was plastic.
• survey included cities, villages and refugee camps in Palestine.
• shows instance of availability of plastic waste for feedstock in developing world

Open Design-Based Strategies to Enhance Appropriate Technology Development[edit | edit source]

Buitenhuis, A. J., Zelenika, I., & Pearce, J. M. (2010). Open Design-Based Strategies to Enhance Appropriate Technology Development. Proceedings of the 14th Annual National Collegiate Inventors and Innovators Alliance Conference : Open, March 25-27th 2010, pp. 1-12.

Available online [4]

• covers the use of the open source philosophy in facilitating appropriate technology and sustainable development.
• discusses technical, economic and social barriers to such a strategy.
• frames the philosophy of this project.

Waste for Life: Student learning through international development projects. Who Pays and who benefits?[edit | edit source]

C. Baillie, "Waste for Life: Student learning through international development projects. Who pays and who benefits?" Materials Today, 11(10) , pp. 6, 2008.

online here

Notes:

• Author's experience with a development inititive in Buenos Aires, Argentina.
• states the importance of good project planning, consultation with local communities and collaboration with reputable organizations when working on development projects.
• outlines the process Waste for Life undertook in launching their project.
  • first met with interested groups in Argentina
  • designed low cost prototype after determining local needs.
• developed low cost hot press/compression moulder with the help of Darko Matovic at Queen's University. Used to create cardboard-plastic composite sheets from recycled materials.

Relevance:

• similar project initiative... low cost means of turning waste plastic in usable material.
• precautions for projects targeting third world. Proper research, consultation and cost/benefit evaluation must be conducted before implementing development projects.

Assessing Informal Waste Recycling in Kanpur City, India[edit | edit source]

Zia, H., Devadas, V., and Shukla, S., 2008, "Assessing Informal Waste Recycling in Kanpur City, India", Management of Environmental Quality: An International Journal, 19(5) pp. 597-612.

Abstract:

Purpose – The purpose of this paper is to outline the socio-economic and environmental implications of the informal sector engaged in waste recycling in the city of Kanpur, with special emphasis on the lives of lowest group of people, i.e. waste-pickers, and to discuss various possible scenarios to integrate them with the formal sector.

Design/methodology/approach – The study involved field survey of secondary material markets, followed by the administration of questionnaires to 40 respondents belonging to various segments of the informal sector. The questionnaires were designed to elicit information on the socio-economic characteristics of the respondents. The study was conducted in 2004.

Findings – The study has attempted to delve into the socio-economic conditions of the waste and dump-pickers, the lowest segment of the informal recycling sector. The study of the status of existing alliances of formal-informal sector and the community shows that there is a lot of scope for improvement in the management of solid waste and the condition of the informal waste-recycling sector. Stronger alliances have the potential to improve the services as well as the socio-economic condition of the informal waste-recycling sector.

Research limitations/implications – A very small sample size was selected for this study in the absence of any prior database pertaining to the size, socio-economic conditions of the informal waste-recycling sector.

Notes:

• example of plastics availability in developing world context
• analysis of informal sector recycling
  • perhaps potential for adding value to this process with WPE?
  • social implications?

Solid Waste Recycling and Reuse in Bangkok[edit | edit source]

Muttamara, S., Visvanathan, C., and Alwis, K. U., 1994, "Solid Waste Recycling and Reuse in Bangkok", Waste Management & Research, 12(2) pp. 151-163.

Abstract:

Materials recovered from solid waste in Bangkok are mainly glass bottles, paper and paper products, plastic products and metals. Materials are separated at three different stages of the collection process: at the source, prior to collection; by the crews of the collection vehicle; and by the scavengers at the dump site. The total daily tonnage of recyclable garbage collected at the source by the waste pickers is estimated at 286 tonnes, about 5% of the garbage collected by the city. There are small scale recycling shops (SSR) located around the main disposal sites where collected materials are sold by the collection crews and the scavengers. The quantity of materials delivered to the SSR shops by the collection crew vary between 1-6 tonnes per day. The amount of materials recovered by the scavengers (at the dump site) varies between 50-150 kg person-1 day-1. Therefore around 7.5% of the solid waste is recycled. In Bangkok both formal and informal sectors manufacture paper pulp, cardboard boxes and magazines from the recyclable paper. Paper products which account for 55% of the total waste stream are considered as the largest "product group" in the municipal solid waste. Recyclable glass (1-3% of the total waste stream) or cullet is used to manufacture plain glasses or cups. Plastics constitute about 10-15% of the waste stream. The benefit/cost ratios of production of most of these industries were reported to be higher than 1.5. In order to enhance recycling, legislative measures need to be introduced and enforced. In Thailand, there is, however, no law concerning recycling. There is no incentive for the consumer to separate solid waste for recycling, as the prices of waste in Bangkok are low and inconsistent. Therefore the pricing system should be more organized for recycling to be more effective.

Notes:

• further example of availability of plastics for recycling.
• evaluation of existing recycling systems
• potential for value added to recycling process?