DEGREE PROJECT IN CHEMICAL ENGINEERING AND TECHNOLOGY, FIRST LEVEL STOCKHOLM, SWEDEN 2016

Cellulose and polypropylene filament for 3D printing Isabella Kwan

KTH ROYAL INSTITUTE OF TECHNOLOGY KTH CHEMICAL SCIENCE AND ENGINEERING

DEGREE PROJECT Bachelor of Science in Chemical Engineering and Technology

Title:

Cellulose and polypropylene filament for 3D printing

Swedish title:

Cellulosa och polypropen filament för 3D-utskrivning

Keywords:

Additive manufacturing, 3D printing, extrusion, polypropylene, filament

Work place:

Innventia AB

Supervisor at the work place:

Fredrik Berthold Henrik Pettersson

Supervisor at KTH:

Elisabet Brännvall

Student:

Isabella Kwan

Date:

2016-09-16

Examiner:

Elisabet Brännvall

Abstract Additive manufacturing has become a very popular and well mentioned technique in recent years. The technique, where 3 dimensional (3D) printing is included, creates opportunities to develop new designs and processing systems. As a research institute within the forest based processes and products, Innventia AB has an idea of combining 3D printing with cellulose. The addition of cellulose will increase the proportion of renewable raw material contributing to more sustainable products. However, when cellulose is added the composition of the filaments changes. The main aim for the project is to devise methodologies to improve properties of composite filaments used for 3D printing. Filament in 3D printing refers to a thread-like object made of different materials, such as PLA and ABS, that is used for printing processes. A literature study was combined with an extensive experimental study including extrusion, 3D printing and a new technique that was tested including 3D scanning for comparing the printed models with each other. The extruding material consisted of polypropylene and cellulose at different ratios, and filaments were produced for 3D printing. The important parameters for extruding the material in question was recorded. Because the commingled material (PPC) was in limited amount, UPM Formi granulates, consisting of the same substances, was used first in both the extrusion and printing process. Pure polypropylene filaments were also created in order to strengthen the fact that polypropylene is dimensional unstable and by the addition of cellulose, the dimensional instability will decrease. After producing filaments, simple 3D models were designed and printed using a 3D printing machine from Ultimaker. Before starting to print, the 3D model needed to be translated into layer-by-layer data with a software named Cura. Many parameters were vital during printing with pure polypropylene, UPM and PPC. These parameters were varied during the attempts and marked down for later studies. With the new technique, in which 3D scanning was included, the 3D printed models were compared with the original model in Cura in order to overlook the deformation and shape difference. The 3D scanner used was from Matter and Form. Photographs of the printed models, results from the 3D scanner, and screenshots on the model in Cura were meshed together, in different angles, using a free application named PicsArt. The result and conclusion obtained from all three parts of the experimental study was that polypropylene’s dimensional stability was improved after the addition of cellulose, and the 3D printed models’ deformation greatly decreased. However, the brittleness increased with the increased ratio of cellulose in the filaments and 3D models.

Sammanfattning Additiv tillverkning har på den senare tiden blivit en mycket populär och omtalad teknik. Tekniken, där tredimensionell (3D) utskrivning ingår, ger möjligheter att skapa ny design och framställningstekniker. Som ett forskningsinstitut inom massa- och pappersindustrin har Innventia AB en ny idé om att kombinera 3D-utskrivning med cellulosa. Detta för att höja andelen förnybar råvara som leder till mer hållbara produkter. Dock kommer filamentens sammansättning vid tillsättning av cellulosa att ändras. Det främsta syftet med detta projekt är att hitta metoder för att förbättra egenskaperna hos de kompositfilament som används för 3Dutskrifter. Filament inom 3D-utskrivning är det trådlika objektet gjort av olika material, såsom PLA och ABS, som används vid utskrivningsprocessen. En enkel litteraturstudie kombinerades med en experimentell studie. Det experimentella arbetet var i fokus i detta projekt som omfattade extrudering, 3D-utskrivning samt en ny teknik som prövades, där 3D-scanning ingick, för att jämföra de utskrivna modellerna med varandra. Extruderingsmaterialet bestod av polypropen och cellulosa av olika halter, och av detta material tillverkades filament för 3D-utskrivning. De viktiga parametrarna för extrudering med det önskade materialet antecknades. Eftersom mängden cominglat material (PPC) var begränsat, användes först UPM Formi granuler, som består av samma substanser som i PPC, i både extruderingen och utskrivningen. Filament av ren polypropen tillverkades också för att stärka det faktum att polypropen är dimensionellt instabil. Genom att tillsätta cellulosa minskades dimensionsinstabiliteten. Efter att filamenten hade tillverkats, designades enkla 3D-modeller för utskrivning med en 3Dutskrivare från Ultimaker. Innan utskrivningen kunde börja behövde 3D-modellen bli översatt till lager-på-lager-data med hjälp av en programvara vid namn Cura. Många parametrar är viktiga vid utskrivning med ren polypropen, UPM samt PPC. Temperatur och hastighet varierades för de olika försöken och antecknades för senare studier. Med den nya tekniken, där 3D-scanning ingår, jämfördes de utskrivna 3D-modellerna med originalmodellen i Cura för att se över deformationen och formskillnaden. Den 3D-scanner som användes kom från Matter and Form. Fotografier på de utskrivna modellerna, resultaten från 3D-scannern och bilder på modellerna i Cura sammanfogades i olika vinklar med hjälp av ett gratisprogram som heter PicsArt. Det resultat som erhölls och den slutsats som kunde dras utifrån alla tre delarna av den experimentella studien var att polypropens dimensionsinstabilitet minskades efter tillsatsen av cellulosa, och att de 3D-utskrivna modellernas deformation minskade kraftigt. Skörheten ökade ju högre halt cellulosa som filamenten och de utskrivna modellerna innehöll.

Acknowledgements This thesis was done at Innventia AB as a part of TechMark Arena 2016, and this year’s theme was additive manufacturing and 3D forming methods. When the project started, my knowledge about additive manufacturing and 3D forming methods (3D printing) was very limited. During this project I have learnt a lot such as how to produce filaments and how to 3D print. It was an enjoyable process. I would like to thank my supervisors at Innventa, Fredrik Berthold and Henrik Pettersson, for giving me the opportunity to accomplish this project. They have been very helpful from the beginning, both theoretically and practically in the lab, and has given me many ideas and solutions to the problems encountered. Thanks to Karin Edström for introducing TechMark Arena and creating many interesting events. Thank you to all staff and students that, whether involved in TechMark Arena or not, have given me good advice and contributed with good atmosphere in both the lab and the working room. Finally, I would like to thank my examiner from KTH, Elisabet Brännvall, for supporting me and giving good advice throughout the whole project.

Isabella Kwan 2016-09-01

Table of Contents 1. Introduction ................................................................................................................................. 1 1.1 Aim and goal ......................................................................................................................................... 1 1.2 Methodology ......................................................................................................................................... 2

2. Theory ............................................................................................................................................ 3 2.1 Manufacturing techniques .............................................................................................................. 3 2.1.1 Additive manufacturing and 3D printing .......................................................................................... 3 2.1.2 Extrusion ........................................................................................................................................................ 3 2.1.2.1 Twin-screw extrusion ........................................................................................................................................... 3

2.1.3 3D scanning ................................................................................................................................................... 4 2.2 Polymer raw materials ..................................................................................................................... 4 2.2.1. Chlorinated polyethylene elastomer.................................................................................................. 4 2.2.2 Acrylonitrile butadiene styrene ............................................................................................................ 4 2.2.3 Polylactic acid ............................................................................................................................................... 4 2.3 Pulp fibers ............................................................................................................................................. 5 2.4 Polypropylene...................................................................................................................................... 5 2.5 UPM .......................................................................................................................................................... 6

3. Materials and equipment ......................................................................................................... 7 4. Methods.......................................................................................................................................... 8 4.1 Manufacturing techniques .............................................................................................................. 8 4.1.1 Extrusion ........................................................................................................................................................ 8 4.1.2 3D printing.................................................................................................................................................. 10 4.2 Comparison technique .................................................................................................................... 11 4.2.1 3D scanning ................................................................................................................................................ 11 4.2.2 Image merging .......................................................................................................................................... 12

5. Results .......................................................................................................................................... 15 5.1 Extrusion.............................................................................................................................................. 15 5.2 3D printing .......................................................................................................................................... 16 5.3 3D scanning ........................................................................................................................................ 17 5.4 Comparison ......................................................................................................................................... 18

6. Discussion ................................................................................................................................... 22 6.1 Extrusion.............................................................................................................................................. 22 6.1.1 Errors and problems............................................................................................................................... 22 6.2 3D printing .......................................................................................................................................... 23 6.2.1 Errors and problems............................................................................................................................... 23 6.3 3D scanning ........................................................................................................................................ 24 6.3.1 Errors and problems............................................................................................................................... 24 6.4 Comparison ......................................................................................................................................... 25 6.4.1 Errors and problems............................................................................................................................... 25

7. Conclusion ................................................................................................................................... 27 8. Recommendations of further work .................................................................................... 28 9. References ................................................................................................................................... 29 Appendix 1 – Extrusion parameters ....................................................................................... 31 Appendix 2 – Printing parameters .......................................................................................... 33

Appendix 3 – Dimension comparison .................................................................................... 39 Appendix 4 – Materials ................................................................................................................ 41 Appendix 5 – Pictures from extrusion ................................................................................... 42 Appendix 6 – Pictures from 3D printing ............................................................................... 43 Appendix 7 – 3D models made of different substances ................................................... 44

1. Introduction Innventia AB is a Swedish research institute focusing on research, development and innovation alongside direct consulting and development assignments within the pulp and paper industry, graphics industry and packing industry. By adapting new, modern and advanced processes the institute aims to develop new ideas for the future. [1] In recent years, additive manufacturing has become the most up-to-date technique, which threedimension (3D) printing is included, in order to produce new designs and processing systems. The usual plastics used for 3D printing are chlorinated polyethylene (CPE), acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA). Which plastic to be used depends on what the purpose is with the printed model. All the plastics named above are quite expensive but stable. Adding cellulose to these plastic filaments will increase the proportion of renewable raw material but the filaments’ composition will change. This project will examine the use of polypropylene as plastic in combination with cellulose at different ratios to produce filaments for 3D printing. Polypropylene was chosen because it is a commonly used and cheap plastic, and the cellulose used is in the form of softwood pulp. Although, a consequence with polypropylene is its dimensional instability, and the compatibility of polypropylene with cellulose is poor but can be solved with the addition of additives such as MAPP. The dimensional instability and shrinkage of polypropylene will decrease after the addition of cellulose making it possible to 3D print with. The addition of cellulose also increases the proportion of renewable raw material contributing to more sustainable products.

1.1 Aim and goal The main aim with the thesis is to devise methodologies to improve properties of composite filaments used for 3D printing, but also to get a deeper knowledge about additive manufacturing. The goal with this project is to produce filaments out of polypropylene mixed with cellulose which is supposed to make the filament more stable. The produced filament will be used to print 3D models which enables the change of the cellulose additive to be seen. In order to achieve the goal, the following research questions are to be answered: 1. Can the dimension stability of polypropylene increase with the addition of cellulose? 2. Which parameters are vital, and which can be ignored, when extruding and 3D printing? 3. Which are the optimal settings when 3D printing with filaments of pure polypropylene and filaments with cellulose and polypropylene? 4. How much do the printed models deform in comparison with models in the CAD program Cura?

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1.2 Methodology During the project, both a literature and experimental study will be included. The experimental study will involve extruding a material consisting of polypropylene and different amounts of cellulose. To find the optimum parameters for extrusion and printing, commercially available granulates containing polypropylene and cellulose, UPM Formi, will be used before using a commingled material of polypropylene and cellulose pulp fibers. This material will be named PPC. Pure polypropylene filaments will also be created. The filaments will be used to 3D print models and a 3D scanner will later on be used to identify the shape difference of the 3D printed models in comparison to the models in the CAD program Cura.

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2. Theory 2.1 Manufacturing techniques 2.1.1 Additive manufacturing and 3D printing Additive manufacturing (AM) is a more formal and standard term for what was earlier called rapid prototyping (RP). More lately, additive manufacturing has become more known as threedimensional (3D) printing. RP is referring to the process of producing objects rapidly from a 3D model data, a computer-aided design (CAD) system, usually layer-by-layer. By using the AM technology, it has become easier to produce complex 3D objects without the need for process planning. Other manufacturing processes such as additive techniques, freeform fabrication and fused deposition modeling (FDM), require careful and detailed analysis, and in some cases the machinery and/or the processes are very complex and expensive. The named technologies are suitable for high valued industries and applications. These include industries of aerospace, automotive and biomedical products. However, the AM technologies only required a basic understanding of how the machine works, the used materials properties and dimensional details of the model. [2] [3] [4] [5] In 3D printing, filament is a long, threadlike object [6] that has a diameter of 1,75 or 2,85 mm depending on the printer used. These filaments are made of fibers or plastics such as PLA and ABS, and is the material the designed 3D model will printed with. [7] In the layer-by-layer process, each layer is built up of a thin cross-sectional slice of the CAD data. In other words, the CAD program will make thousands of calculations in order to determine how each layer will be printed exactly. The thickness of each layer determines how the final result of the product will be. The thinner the layers, the more the final product will resemble the CAD model. Not only the thickness of the layers, but also how the layers are created, how they are fused to each other and what material is used, will affect the final product. How long the process of turning a CAD model into a real, useful product will be depends on the chosen AM technology. [2] [3] [4]

2.1.2 Extrusion Extrusion is the method for producing filaments and can be divided into two different types: single-screw extrusion and twin-screw extrusion. Since this project will only examine twinscrew extrusion (Appendix 5 Figure 19 and 25), single-screw extrusion will not be concluded. 2.1.2.1 Twin-screw extrusion Twin-screw extrusion was developed alongside single-screw extrusion in the beginning of the 20th century, and has for the past 30 years gone through a rapid growth. The extruder includes: “two parallel screws, rotating inside a barrel with a figure-eight cross-section.” [8] The screws may differ between different extruders. The two most important dissimilarities to distinguish twin-screw extruders apart are in what direction the screws are rotating and the interpenetration between the two screws. The two screws can rotate either in the same direction or in opposite directions. If the screws rotate in the same direction it is called co-rotating and if the screws 3

rotate in opposite directions, it is called counter-rotating. Interpenetration is how close the screws are to each other. If an extruder is interpenetrated, it means that one of the screw’s flight penetrates the channel of the other screw. The interpenetration can either be partial or complete. [8] [9]

2.1.3 3D scanning The most common technique used is laser scanning, and ever since the laser was introduced in the 1960s, the technique has been used for landscape and architecture purpose. 3D scanning is used for recording and collecting data for analysis from an object’s actual 3D shape, and is applicable into, among other, 3D visualization and modeling, cloud-to-cad comparison, prototyping, architectural data requirements and digital archiving. [10] [11]

2.2 Polymer raw materials Polymers used today for 3D printing are polycarbonate (PC), nylon, thermoplastic polyurethane (TPU), chlorinated polyethylene (CPE), acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA). All the named plastics, except for PLA, are made from fossil raw materials, expensive and difficult to degrade.

2.2.1. Chlorinated polyethylene elastomer Chlorinated polyethylene elastomer (CPE) is a polymer produced by chlorinating polyethylene. CPE have both very good mechanical and physical properties including chemical, heat, oxidation and weather resistance and have good tensile strength. The polymer is very versatile because it is both a flexible elastomer and a rigid thermoplastic. CPE can be blended with other plastics such as ethylene vinyl acetate (EVA) and polyvinyl chloride (PVC) to improve the plastics dimensional stability but also to achieve different properties. CPE is commonly applied in building products, wire and cable jacketing, automotive and industrial hose and tubing. However, as many other plastics, CPE is difficult to degrade and known emissions while combusting are hydrogen chloride and carbon monoxide which are toxic to the environment. Carbon dioxide is also released which is a greenhouse gas. [12] [13]

2.2.2 Acrylonitrile butadiene styrene Acrylonitrile butadiene styrene (ABS) is a thermoplastic produced by mixing three monomers together, acrylonitrile, butadiene and styrene. By combining all these three monomers, and in some cases even a few more monomers, the plastic’s properties will improve. Benefits that are achieved are good dimensional stability, improved mechanical and impact strength, and heat and chemical resistant. Because of this, ABS are used in Lego, automotive parts, pipes and industrial products. However, the plastic is hard to degrade and is relatively expensive. [14] [15]

2.2.3 Polylactic acid Polylactic acid (PLA), or polylactide, is a bio-based polyester made from monomer lactic acid produced from catalyzed fermentation of sugar or starch by microorganisms. PLA have some poor material properties such as low heat and impact resistance. Due to this, PLA is often mixed 4

with other common petro plastics such as polyethylene terephthalate (PET) in order to increase its impact and heat resistance. The plastic is biocompatible and is relatively cheap in comparison to other plastics used for 3D printing. [16] This have made PLA into a very common plastic around the world with applications in among other 3D printing, medical implants and packaging.

2.3 Pulp fibers Pulp is a fibrous raw material, either wood or nonwood, that are used when producing paper and cellulose products. The pulp fibers produced from paper and pulp industries can be created in three ways: mechanically, chemically and/or biologically. The most commonly used method is chemically where the kraft process is dominant. [17] [18] During the chemical pulp process, the fibrous raw material is cooked in an aqueous solution consisting of chemicals that will separate the fibers by dissolving and breaking down the raw materials’ lignin. In more recent times, organic solvents are used more frequently. The goal with chemical pulping is to remove all the lignin, but all lignin cannot be removed no matter what processes or solutions are used. When the kraft process is performed, an alkaline sulfate solution, usually sodium sulfate (Na2SO4) and sodium hydroxide (NaOH), is used which will make the produced pulp both stronger and darker in color than pulp made of acidic solutions. The pulp has a darker color because of the remaining 2–5 % lignin in the mass. The remaining lignin can be removed through bleaching processes of the chemical pulps. [17] [18] Bleaching is used for increasing the brightness of chemical or mechanical pulps and is a chemical process. Alkaline pulps from kraft pulping processes and softwood pulps are more difficult to bleach. There are two different methods of bleaching; lignin degrading bleaching or lignin preserving bleaching. Lignin degrading bleaching will remove the remaining lignin and is performed through several bleaching sequences using chlorine- and/or oxygen-based chemicals. During lignin preserving bleaching, the lignin will be freed of chromophoric groups and the process is carried out in either one or two steps using hydrogen peroxide (H2O2) and/or sodium dithionite (Na2S2O4). Usually if the bleaching process contains several steps, each step is separated with a washing step in order to remove degraded lignin and residual chemicals. [17] [18]

2.4 Polypropylene Polypropylene (PP) is a thermoplastic containing long chains of propylene. This plastic is very common and useful because of its good mechanical properties and low cost. Examples of applications are ropes, carpets, mobile shells and office supplies. Even though the plastic has good mechanical properties and a low cost, it has a melting point at approximately 130 °C. For a plastic, that temperature is relatively low and makes polypropylene both dimensionally and thermally unstable. To print 3D models using polypropylene is difficult because of dimensional and thermal instability which will lead to deformation on the models. [19]

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2.5 UPM UPM Formi granulates are made of pure polypropylene and reinforced with cellulose fiber with a high content of renewable material. There are four different renewable material content (cellulose content) 20, 30, 40 and 50 weight %. By adding cellulose fiber into pure polypropylene, the strength and stiffness increases along with the brittleness. The granulates are primarily designed for injections molding but can also be used for extrusion. [20]

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3. Materials and equipment The cellulose used in the experiment was fully bleached sulphate pulp of softwood from Södra Cell. Two different kinds of polypropylene were used, where one was in fiber form called Create WL (1,7 dtex – 6 mm) from a Danish company named Fibervisions. The other polypropylene was in granulated form called Polypropylene homopolymer HJ40XI from Polychim Industrie in France. The used UPM Formi granulates (Appendix 4 Figure 17) are called UPM Formi GP from UPM – The Biofore Company in Finland. The used granulates had four different cellulose contents: 20, 30, 40 and 50 weight %. In the thesis, these will be named UPM20, UPM30, UPM40 and UPM50. Table 1 shows the physical and mechanical properties of UPM Formi at different cellulose content. Table 1. Physical and mechanical properties of UPM Formi at different cellulose content [20]

Property Test method GP 20 GP 30 GP 40 GP 50 3 Density, g/cm ISO 1183 0,99 1,03 1,08 1,13 2 Tensile strength, 50 mm/min, N/mm ISO 527-2 33 43 53 57 2 Tensile modulus, 1 mm/min, N/mm ISO 527-2 2100 3100 3800 4800 Elongation at break, 50 mm/min, % ISO 527-2 7,5 6,3 5,2 4,0 Cellulose content, weight % 20 30 40 50 The used equipment for the experiment includes a L&W Pulp Disintegrator from Lorentzen & Wettre, a bigger blender from IKA Labortechnik, a small extruder named HAAKE MiniLab from Thermo Scientific, a big extruder called LabTech LTE-20-48, and a heating gun called Steinel HG 2310 LCD. Two 3D printers, model 2 and model 2+, were used both from Ultimaker. The used 3D scanner came from Matter and Form. Three free softwares were used: Cura for 3D printing, Matter and Form Scanner for 3D scanning, and PicsArt for merging images in the comparison.

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4. Methods The methodology can be divided into two parts: manufacturing techniques and analysis.

4.1 Manufacturing techniques The used manufacturing techniques were divided into two parts: extrusion and 3D printing.

4.1.1 Extrusion Two different extruders were used during the experiment, one smaller more manual and one bigger with more varied temperature along the machine. Before running the extruder, material had to be prepared. Four different UPM granulates were used: UPM20, UPM30, UPM40 and UPM50. The granulates have to be dry, or at least have a relatively low humidity, prior the extrusion. In order to dry the granulates, they were placed in an oven at 50 °C for about one week. The commingling process of cellulose and polypropylene (PPC) began with weighing teared softwood pulp into four small plastic jars. Each plastic jar was marked with 20, 30, 40 and 50 g respectively. The same amount of softwood pulp was put into the jars and then filled with water to later be placed in the refrigerator for 24 h. To loosen up the cellulose fiber, the pulp was poured into a pulp disintegrator with fixed (10 000) rotations, see Figure 1a. In order to add the polypropylene fiber, the premixed pulp was put in a plastic bucket and filled with 10 L water. The amount of polypropylene fiber varied from 50 g to 80 g, making the total weight of each material 100 g. The bucket was placed under a bigger blender set up of a stand and a motor with adjustable speed with associated rotor blades, see Figure 1b. After starting the blender, polypropylene fiber was poured in and the pulp mixture then blended for 1 h. Vacuum filtration was used to strain off the water and the pulp mixture was dried in an oven at 50 °C for approximately one week, see Appendix 4 Figure 18.

Figure 1a. Pulp disintegrator with fixed rotations

Figure 1b. Blender with adjustable speed

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Before extruding, the extruder needs to be pre-heated to the required temperature. The temperature is usually set right above the material’s melting point. Since the outlet of the extruder is rectangular, a die needs to be attached to the extruder in order to make the produced filaments round. The material to be extruded is inserted into the inlet of the heated extruder. The material will slowly melt and enter the two rotating screws’ path. Material needs to be fed in continuously using a T-shaped handle to push the material, see Figure 2. Slowly the melted material will come out through the machine and filament have been made. However, there is nothing to roll up the filament that is coming out. Due to this problem, the filament was let to drop on the floor and the filament became uneven at some points. In order to straighten out the filament before 3D printing, since the filament has to be even and smooth before entering the printer, a heating gun was used. The heating gun, looking like a hair dryer, had two preset temperatures, at 50 °C and 350 °C. The higher temperature was chosen. When heating, the filament was held at a reasonable distance from the gun. The exposure of the filament under the heat was not long since the temperature was very high for the filament. By the heat, the filament softened which made it bendable. During this process, caution must be taken since the filament may break.

Figure 2. Extrusion running with PPC using the small extruder

To find the vital extrusion parameters, UPM granulates were extruded first since the UPM pellets were commercially available and the PPC material was in limited amount. Table 4-11 in Appendix 1 shows the varied parameters from the first round of extrusion. After a few trials of printing using the PPC filaments, the result was not good enough for further analysis. The obtained results looked fluffy and hairy. The material flow was not constant making a lot of empty space which meant that the printing process had to be stopped. Another decision was taken, to extrude all the PPC filaments once again in order to make the filaments straighter and more homogeneous. This time the big extruder (Appendix 5 Figure 21), with longer screws, was used.

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4.1.2 3D printing The used 3D printer for this experiment was from Ultimaker [7], see Figure 3, and before starting to print, a few things that had to be prepared. A 3D model has to be designed and can be done so freely, but with dimensions within the printer. Cura is a software that translates the designed 3D model into instructions that the printer will understand. Literally, it slices up the 3D model into layers, just as 3D printing is done, layer-bylayer. In Cura, several settings can, and in most cases need to, be adjusted such as nozzle size, layer height, infill density, print speed etc. depending on what material is used for printing and how detailed the model needs to be. After making the required adjustments for a specific 3D model, it should be saved as printing instructions and transferred to the printer’s memory card.

Figure 3. Ultimaker 3D printer

The settings that cannot be set with Cura, like the nozzle’s temperature, the build plate’s temperature and the filament’s diameter, need to be adjusted on the printer directly. Another thing that have to be done manually is to change the nozzle to match the set size parameter in Cura. To change filament, the old filament needs to be ejected, which is done by the printer, and the new filament will be inserted. Calibration of the build plate is also an important step to do before starting to print. After the calibration, it is time to set the temperature for both the build plate and nozzle, but also adjusting the diameter setting of the filament in the machine to the actual filament diameter. The temperature on the nozzle need to be set so that material can flow out continuously. However, the highest possible temperature on the nozzle was 260 °C and the maximum temperature on the build plate was 100 °C. Many different temperatures on both the nozzle and build plate were tested as well as some other parameters such as speed, flow rate, nozzle size and infill density. The diameter of the filament was measured randomly over the filament using digital calipers. The different tested temperatures, print settings and filament diameter for UPM, pure polypropylene and PPC are shown in Appendix 2 Table 12-18. For more pictures of the printing process, see Appendix 6, and for pictures of the 3D models obtained using different substances from the printing process, see Appendix 7.

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4.2 Comparison technique The comparison technique included 3D scanning and merging images in order to see the deformation changes.

4.2.1 3D scanning The used 3D scanner for the experiment was from Matter and Form [21]. The scanner is a laserbased scanner and works by shining a laser at an object. The camera of the scanner will collect data from the laser returning from the object and a software will put all the data together that will be shown on the computer screen. An important step before starting to use the scanner is to calibrate it. There are a few parameters that are important to consider in order to get a good scanning result. The object scanned should not: be transparent since then the laser will go through the object, be shiny because the laser will reflect or bounce on the object, and not be too dark since the laser will then be absorbed. Other important parameters to consider when scanning is the environment and the lightning on the object. If the lightning is too bright, the scanned object’s color will be uneven and hot spots will appear. However, if the lightning is too dark or dim, the object may not be fully scanned and the object may also be discolored. After placing the object on the turntable and before starting the actual scan, the scanner began to tune for object shape, object color and lightning. Once the tuning was done the scanning process started automatically, see Figure 4. During the process, the outcome of the scan was shown on the computer screen. However, the scanner had trouble scanning deep objects, which many of the models were. When the scanning was done, the scanner stopped automatically, prepared for scanning a new object or another side of the current one. Later, the scanned result had to be cleaned because the scanner sometimes picked up and added unintended points to the scan. This step is very important prior to combining different scans and before meshing. The cleaning should be as exact as possible, which means all unnecessary points should be cleaned. There are three options that can be used during cleaning: crop points, brush cleaning and fuzzy points (auto clean). The option chosen was brush cleaning because it is the best option for removing individual points.

Figure 4. Laser firing at the object

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Usually, one scanning angle is not good enough for getting a complete scan of an object and some points may even be missed. Making two or more scans of the same object but at different angles and then combining the separate scans after cleaning will help fill in the missing points, see Figure 5. This process is an automatic process that identifies key points by using mathematical algorithms from two different scans. The key points will be lined up so the scans can overlap.

Figure 5. Combining process of scans at different angels

The meshing of a scanned object was later made in order to turn the file into a format that could be opened in Cura. The meshing process connects the points and produces a smoother object. As mentioned previously, the scanner had trouble scanning deep models and this also applies when meshing objects. Since many of the printed models had a deep part, the meshing process for that part was covered.

4.2.2 Image merging A new technique for the comparison of the original models and the printed/scanned models was tested. The method was to merge images of the objects/results and compare them with the original 3D model from Cura. Photographs were taken on the printed models in different angels. A photograph editor application that could merge photos together was opened up on the computer. For this test, a free application named PicsArt was used. After selecting and opening an image, the other image needed to be created. The same model as in the photograph taken was opened up in Cura. After adjusting the size and angle of the model, a screenshot was taken. The screenshot was slightly edited in the classic software program Paint and saved. Back to PicsArt, the button Add photo was hit and the newly saved screenshot was selected. After opening up the image over the photograph, at the bottom of the images, the opacity could be chosen, see Figure 6. Since the 12

maximum opacity was 255, half of the maximum was chosen, 122. The size of the screenshot needed to be adjusted, which depended on how much the 3D model was zoomed in Cura. The image could also be rotated by hitting and dragging the button with two arrows either to the left or right.

Figure 6. PicsArt meshing process

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The model in Cura and the model in the photograph have to be in the same angle and size in order to see the difference. If the screenshot of the model in Cura was not in the same angel and size even after zooming and rotating, a new screenshot had to be taken adjusting the size and angle of the model in Cura. In Figure 7, the merging process of two images is shown.

Figure 7. Meshing process of a photograph and screenshot from Cura

14

5. Results The results of each part will be presented below. Two different materials were used, UPM Formi granulates with four different cellulose ratios, called UPM20, UPM30, UPM40 and UPM50. The other material was commingled consisting of polypropylene and the same ratio of cellulose as the UPM samples, called PPC20, PPC30, PPC40 and PPC50. The number beside the substance in Table 2 and 3 refers to the cellulose content. In order to see the deformation reduction by the addition of cellulose, pure polypropylene filament and 3D models were also produced.

5.1 Extrusion The vital parameters for extruding were temperature, torque, speed of the screws and how the produced filaments were twined. Table 2 shows the optimal temperature and speed for producing filaments for each substance while using the small extruder. The filament from PPC50 was extruded twice. This was because the filament became square shaped after the first extrusion. When 3D printing, the filaments have to be rounded so a decision was made to make pellets of the produced filament in order to extrude the material again. Table 2. Results from small extruder

Substance Temperature [°C] Speed [1/min] Polypropylene UPM20 180 50 UPM30 177 35 UPM40 190 50 UPM50 193 70 PPC20 180 40 PPC30 180 40 PPC40 190 45 PPC50* 190 40 * = extruded twice The bigger extruder was used for the second extrusion. The big extruder had longer screws and the temperature varied from 180 °C to 190 °C along the screws.

15

5.2 3D printing The most important parameters when printing, no matter what material is used, are: the temperature of the nozzle, the size of the nozzle, the diameter of the filaments, the build plate’s temperature, what base is used when printing, layer height, infill density and print speed. Factors that affected the printing process, except of the named parameters above, with pure polypropylene, UPM and PPC was: material, deformation, filament input, material flow, and the space between the nozzle and build plate. Table 3 shows some of the optimal parameters while 3D printing. However, no result was obtained for UPM30 and UPM40 because the substances was not tested due to lack of time. For more details on different parameters tested, see Table 12-18 in Appendix 2. Table 3. Optimal values of 3D printing parameters

Substance

Build plate [°C] Polypropylene 0

Nozzle [°C] 187

Print speed [mm/s] 15

UPM20

0

190

15

UPM30 UPM40

-

-

-

UPM50

0

235

15

PPC20

0

235

15

PPC30

0

245

15

PPC40

0

245

15

PPC50

0

240

15

Base Rough thick PP plastic film Rough thick PP plastic film Rough thick PP plastic film Rough thick PP plastic film Rough thick PP plastic film Rough thick PP plastic film Rough thick PP plastic film

16

5.3 3D scanning Figure 8 shows the result of a successful combined scanned 3D model before meshing.

Figure 8. Combined scanned 3D model

Figure 9 shows the result after meshing the scanned 3D model.

Figure 9. 3D model after meshing

17

5.4 Comparison In an attempt to examine the deformation, the dimensions of the 3D printed models was measured using digital calipers and compared to the original dimensions of the 3D model in Cura, see Appendix 3 Table 19-25. Figure 10 and 11 shows the deformation difference of the printed models. Figure 10 is a comparison between pure polypropylene and polypropylene with 20 (PPC20) and 50 (PPC50) % cellulose ratios. Figure 11 is the same comparison but between UPM20 and UPM50.

Figure 10. Comparison between 3D printed models of pure polypropylene and PPC20 and PPC50

Figure 11. Comparison between 3D printed models of pure polypropylene and UPM20 and UPM50

From the figures, the printing result difference can also be seen in comparison to pure polypropylene. The model in the middle contains 20 % cellulose, where Figure 10 is made of PPC and Figure 11 is made of UPM. Comparing these two, the PPC model has a rougher surface and darker color while the model printed with UPM has a lighter, almost reflective, and smoother surface. It also had more deformation than the model made of PPC. Not much difference can be seen between the models in the figures made with a cellulose ratio of 50 %. The model printed with PPC had a rougher and more uneven surface than the model printed with UPM.

18

Figure 12 shows the result of two meshed images, where one of the images is a photo taken of the 3D printed model and the other image is a screenshot of the model in Cura. Figure 13 is the same as Figure 12 but in a different angle.

Figure 12. Meshed image of the model in Cura and photograph

Figure 13. Meshed image of the model in Cura and photograph in different angle

19

Figure 14 shows two meshed images, but this time one of the images is a screenshot of the scanned model from Matter and Form, while the other one is a photo taken from the same model as in Figure 12 and 13.

Figure 14. Meshed image of the model in Matter and Form and photograph

Figure 15 shows two models beside each other. The model to the left in the image is how the model should look originally from Cura and the model to the right is the model scanned, meshed together using the Matter and Form software and translated into a format able to be opened in Cura.

Figure 15. Cura model and meshed model beside each other

20

Figure 16 is the same two models as in Figure 15, but from a different angle. In the image, it is seen that the deep part of the model to the left is covered.

Figure 16. Cura model and meshed model beside each other in a different angle

A simple comparison was also done between the materials used, PPC and UPM. The best material for 3D printing was UPM. The obtained result considered among other how many times the material was extruded, deformation and the difficulty when printing. Since UPM30 and UPM40 was not tested, the best cellulose ratio for UPM was 50 weight %.

21

6. Discussion 6.1 Extrusion The vital parameters when extruding are temperature, torque, speed of the screws and how the produced filaments were twined. Two of these parameters, temperature and speed, were measured for each material using the small extruder which is shown in Table 2. However, torque, the strength put on the screws, was not measured because it depended on the temperature, speed and feed rate of the material. When using the small extruder, the material flow was controlled manually which lead to very variated numbers. Even though it was not measured, torque is an important parameter when extruding. To find the optimal temperature and speed, every attempt is shown in Appendix 1 Table 4-11. The last attempt of each material was set as the final temperature and speed that is shown in Table 2. However, the result obtained should not be considered as optimal result for the whole extrusion process because the material was extruded different amounts of times. How many times the material is extruded affects the outcome of the filaments. The second time extruding (third time for PPC50), the speed and temperature was not marked down as the bigger extruder was used, and the bigger extruder had more varied temperature along the screws. One thing to take notice of was that the chosen temperature for the bigger extruder were based on the results of the small extruder, so the temperature was set between 180 °C and 190 °C. The speed was also varied depending on the outcome of the filament. As shown in Table 2, there is no result obtained for polypropylene because no usable filament was obtained from the small extruder due to the thermal instability. However, polypropylene filament was successfully produced using the bigger extruder.

6.1.1 Errors and problems The shown temperature and speed for each material in Table 2 are based on the last attempt which might be slightly inaccurate because the number of attempts varied from sample to sample. The reason for this was because when the produced filament was of good quality, even though if the process was a bit slow, the temperature and speed was not adjusted and kept stable. If more time was given to the project, even more accurate results could have been obtained. Since there was no good method to twine the produced filaments together, they became uneven and sometimes rough. Because of this, the filaments needed to be straightened and smoothened which took valuable time from the project, and during that process, some filaments broke because of the brittleness. In some cases, the diameter of the filaments varied very much and for example, the filament after extruding UPM50 was too thick to print with. As mentioned in chapter 3.1, problems occurred with the produced PPC50 filament. The filament became square shaped and the decision was made to cut it into pellets and to extrude the material again in order to reduce the size of the fibers. Another problem mentioned was that the printed 3D models was not good enough for further analysis, and the material flow was not continuous during the printing process. In order to produce a good 3D model, the material flow have to be continuous, and one speculation was that the particle and fiber size was too big for the chosen nozzle size (the biggest was 0,8 mm). After the second time of extrusion the result was

22

improved. Even though the result was improved, the produced filaments became more brittle than the first time extruding.

6.2 3D printing Many parameters are vital when 3D printing and the most important parameters found when printing with the three different materials were: temperature on the nozzle, the size of the nozzle, the diameter of the filaments, the build plate’s temperature, what base is used when printing, layer height, infill density and print speed. However, these parameters were not the only things affecting the 3D model. Factors such as material, deformation, filament input, material flow and the space between the nozzle and build plate, also affected the printing process. However, some of these parameters such as layer height were not tested. Table 3 shows some of the optimal parameters while 3D printing, but since UPM30 and UPM40 were not tested due to lack of time, no result was obtained. The first few attempts using the printer was made using UPM filaments since the PPC filaments were limited. The result in the table were obtained by using filaments from the second round of extrusion (the third time for PPC50). Because of the one extra time of extrusion, the material flow was more continuous which resulted in better 3D models. This was because the particles and fibers were broken into smaller parts, but with this they became more brittle. In Table 12-18 in Appendix 2, the successful attempts of printing are displayed. Each material had different amount of attempts, and out of these, only a few could be used for analysis. The number of successful attempts varied because the filament was either limited or difficult to print with.

6.2.1 Errors and problems The temperature and size of the nozzle is a part of deciding how fast the material will flow through the nozzle. If the temperature is too low or the nozzle size is too small, the material will not melt nor will it flow continuously making the 3D printed model uneven. However, the temperature of the nozzle was limited while using a Ultimaker printer. The maximum nozzle temperature is 260 °C so the material of choice will be affected. As shown in Tables 12-18 in Appendix 2, the temperature of the nozzle was very high, almost maximum. However, since there was cellulose in the filaments used, a high temperature made the printed models darker in color and in some cases a burnt smell came from the printer. The diameter of the filament will affect the filament’s input to the machine, and if the diameter is too small, which happened during some attempts of printing, the result will not be good because the material flow was uneven. The optimal diameter of the filament for 3D printing using a Ultimaker printer was 2,85 mm [7]. The produced filament’s diameter varied quite much and if the diameter was too thin, a helping hand had to be given when printing in order for the filament to flow continuously. However, in some cases the filament broke by the force put on the filament forcing the printing process to stop. The build plate’s temperature and the base used when printing affected the attachment of the printing model. At the first few trials of using the printer, the model did not adhere to the build

23

plate so many different methods were tried which are shown in Appendix 2. This problem was solved, with the help of the literature [5], by attaching a thick, roughed (with sandpaper) polypropylene plastic film on the build plate. However, because of the heat from the nozzle, the plastic film warped resulting, in some cases, that the printed model’s bottom also became uneven and deformed. Another problem that occurred using the plastic film was that the printed model attached too well to the plastic film making it hard to separate the two. This problem occurred especially if it was material containing a high ratio (50 %) of cellulose. Because of this, some of the models’ bottoms were damaged. Infill density and print speed were two parameters adjusted in Cura. Both of these parameters will affect the time taken to print and the final result. The infill density was varied depending on the designed model, and so was the printing speed. However, the optimal printing speed for all designed models was 15 mm/s. The space between the nozzle and build plate depended on the calibration of the build plate which was done manually. The calibration only affected the first layer of the model and if that layer was not done properly, the whole model was affected and a bad result was obtained. This problem occurred especially when printing with pure polypropylene. During the printing process, the attachment of the model to the plastic film was good but since the film became uneven it affected the gap between the nozzle and model. In some cases, the material flow even got smudged making the model looking bad.

6.3 3D scanning The result of the scanning process can be seen in Figures 8 and 9. Figure 8 shows a successful display of the combination of the different scans of the same model. As mentioned in chapter 3.3, the combination process will fill in the missing points of a scan, see Figure 5. Figure 9 shows the meshed version of 3D model in Figure 8.

6.3.1 Errors and problems During the scanning process of the printed models, many factors affected the result. First, the printed polypropylene models could not be scanned since the models were transparent. A trial of using spray paint on the models before scanning was not successful which was probably due to the glossy surface of the color. The glossiness was tried to be reduced by mattifying the surface using sandpaper but with no result obtained. Another problem was the light in the room the scanner was placed in. The lighting varied from time to time even though the lamps’ lighting from the ceiling was constant. The variation of lighting was due to the weather outside the window beside the scanner. Many results after scanning needed much cleaning before it could be combined together, and sometimes the model had to be re-scanned because of the poor result. The light on the object also affected the scanned objects color on the computer screen, making some result darker than others even though the same model was scanned. Because of the re-scanning process, the given time for the project was not enough to try out different lightning support or the advanced function on the scanner.

24

Since the scanner had trouble scanning objects containing a deep part, the meshing process was not successful which is shown in Figure 9. The deep part of the model was covered.

6.4 Comparison As part of the comparison, all models dimensions were measured and compared to the original dimensions of the 3D model from Cura. The results are shown in Table 19-25 in Appendix 3. In order to measure the models, digital calipers were used, and the inner dimensions, or the deep part, of the model was ignored. Figure 10 and 11 shows the deformation difference of the printed models from the same Cura model. Figure 10 shows a comparison between pure polypropylene and PPC20 and PPC50. In Figure 11, the same comparison is done but with UPM20 and UPM50. Figure 12-14 show the result after meshing two images together. This was done in order to examine the deformation of the printed 3D model in comparison to the designed 3D model in Cura. Figure 14 shows the difference between the scanned model and a photograph taken of the printed model in the same angle. Figure 15 displays two models, where the left model in the figure is the original model in Cura. The model to the right is the model scanned and meshed together. Figure 16 is showing the same two models but in a different angle. The meshed model to the left in the image have its deep part covered up, as mentioned before. When comparing the two material used, PPC and UPM, the comparison considered how many times the material was extruded, deformation and the difficulty when printing. The best material was UPM since it only needed one extrusion time. PPC was a commingled material and one extrusion time was not enough because the materials’ particles and fibers were too big making the 3D printed results poor. The big particles and fibers also resulted that the material flow through the nozzle was not constant. PPC needed to be extruded at least three times in order to obtain the same result as UPM that was extruded once (referring to PPC50 in comparison to UPM50). How many times PPC was extruded also affected the deformation of the 3D printed models. Because UPM30 and UPM40 was not investigated, the best cellulose ratio when using UPM was 50 weight %, despite the increasing brittleness with the increased ratio of cellulose.

6.4.1 Errors and problems From the tables in Appendix 3, it is clear that the actual dimensions differed from the original ones. However, the used measuring method might not be that accurate since the calipers was handled manually and every measurement was affected by how hard the model was pinched. Another factor affecting the results was the deformation of the model. Almost every model’s bottom was deformed, making it hard to measure. It can clearly be seen in Figures 10-16 that the printed/scanned model and the model in Cura differs from each other. The models in Cura have sharp edges and a smooth surface, but many

25

of the printed and scanned models have rough, uneven surfaces and blunt edges. This was caused by the material and deformation. The comparison method took more time to finish than planned because the merging process of the different images required the right angle and size in order to show a good result. However, it is a good comparison method.

26

7. Conclusion The addition of cellulose to polypropylene will increase the dimensional stability of a produced filament and reduce the deformation of a 3D printed model. However, the higher the cellulose ratio, the more brittle the filament and 3D model will be. Which parameters that are vital during extrusion depends on how the extruder is structured – is the extruder big or small? Is it a single-screw extruder or a twin-screw extruder? In this study, a twin screw extruder was used and the important parameters were temperature, torque, speed of the screws and how the produced filaments are twined. When 3D printing, the most vital parameter is the material used and many other parameters that are important when printing depends on the material. When printing with pure polypropylene, UPM, and PPC with different cellulose ratio, the important parameters were: temperature on the nozzle, the size of the nozzle, the diameter of the filaments, the build plate’s temperature, what base is used when printing, layer height, infill density and printing speed. Except the parameters above, other factors that affect the printing process are: deformation, filament input, material flow, and the space between the nozzle and build plate. The comparison method used took quite some time to perform, but the result obtained was good. By using the method, the deformation of the models could be compared to the original model in the CAD program Cura. However, the more cellulose content the model contained, the less deformation was shown. An expected result, which was proven to be correct, was that the models printed with pure polypropylene would be much deformed in comparison to the models in Cura. The best material for 3D printing was UPM and the best cellulose ratio for UPM was 50 weight %, despite the brittleness.

27

8. Recommendations of further work 





Continue to extrude the PPC material in order to examine if the 3D printing process will run smoother. From this thesis, it was observed that the particle and fiber size had an impact on the printing process and the obtained 3D models. How many times the material was extruded also affected the deformation. Investigate the tensile strength and tensile modulus by comparing the 3D printed models in comparison to models made from injection molding, for pure polypropylene, UPM and PPC. A method need to be find in order to calculate the deformation on the 3D printed models, since the comparison method used in the thesis did not include any calculations on how much the printed models deformed.

28

9. References [1]

"Innventia," Innventia AB, [Online]. Available: http://www.innventia.com/. [Accessed 21 July 2016].

[2]

I. Gibson, D. Rosen and S. Brent, Additive Manufacturing Technologies, New York: Springer New York, 2015.

[3]

S. S. Muthu and M. M. Savalani, "Introduction," in Handbook of Sustainability in Additive Manufacturing, Singapore, Springer, 2016, pp. 1-5.

[4]

B. Berman, "3-D printing: The new industrial revolution," Business horizons, vol. 55, no. 2, pp. 155-162, 2011.

[5]

O. Carneiro, A. Silva and R. Gomes, "Fused deposition modeling with polypropylene," Materials & Design, vol. 83, no. 1, pp. 768-776, 15 October 2015.

[6]

Merriam-Webster, "Merriam-Webster," Merriam-Webster, 2015. [Online]. Available: http://www.merriam-webster.com/. [Accessed 20 August 2016].

[7]

Ultimaker, "Ultimaker," Ultimaker, 2016. [Online]. Available: https://ultimaker.com/. [Accessed 29 July 2016].

[8]

P. G. Lafleur and B. Vergnes, "Co-rotating Twin-Screw Extrusion," in Polymer Extrusion, Croydon, John Wiley & Sons, Ltd, 2014, pp. 109-198.

[9]

M. Stevens and J. Covas, "Twin-screw extruders," in Extruder Principles and Operation, New Delhi, Springer Netherlands, 1995, pp. 316-348.

[10] A. R. Large and G. L. Heritage, "Laser Scanning - Evolution of the Discipline," in Laser Scanning for the Environmental Sciences, Chennai, Blackwell Publishing Ltd, 2009, pp. 1-20. [11] A. Kus, E. Unver and A. Taylor, "A Comparative Study of 3D Scanning in Engineering, Product and Transport Design and Fashion Design Education," Computer Applications in Engineering Education, vol. 3, no. 17, pp. 263-271, 2009. [12] S&E Speciality Polymers, "S&E Speciality Polymers," S&E Speciality Polymers, 2016. [Online]. Available: http://www.sespoly.com/products/cpe-chlorinatedpolyethylene/. [Accessed 20 August 2016]. [13] Green Spec, "Green Spec," Green Spec, 2016. [Online]. Available: http://www.greenspec.co.uk/building-design/chlorinated-polyethylene-cpe-healthenvironment/. [Accessed 20 August 2016]. [14] spi: the plastics industry trade association, "spi: the plastics industry trade association," spi: the plastics industry trade association, 2015. [Online]. Available: https://www.plasticsindustry.org/AboutPlastics/content.cfm?ItemNumber=1384&navIt emNumber=1128. [Accessed 20 August 2016]. [15] D. M. Kulich, S. K. Gaggar, V. Lowry and R. Stepien, "Acrylonitrile–Butadiene– Styrene (ABS) Polymers," Kirk-Othmer Encyclopedia of Chemical Technology, vol. 1, pp. 414-438, 2003.

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[16] M. Lackner, "Bioplastics," Krik-Othmer Encyclopedia of Chemical Technology, pp. 141, 18 September 2015. [17] Y. Ni and Z. Liu, "Pulp Bleaching," Kirk-Othmer Encyclopedia of Chemical Technology, pp. 1-11, 15 November 2002. [18] J. F. Kadla and Q. Dai, "Pulp," Kirk-Othmer Encyclopedia of Chemical Technology, vol. 21, pp. 1-47, 14 April 2006. [19] S. Mukhopadhyay, B. L. Deopura and R. Alagirusamy, "Studies on Production of Polypropylene Filaments with Increased Temperature Stability," Journal of Applied Polymer Science, vol. 101, no. 2, pp. 838-842, 15 July 2006. [20] UPM, "UPM Formi," UPM - The Biofore Company, 2015. [Online]. Available: http://www.upm.com/formi/Pages/default.aspx. [Accessed 22 July 2016]. [21] Matter and Form, "Matter and Form," 2016. [Online]. Available: https://matterandform.net/. [Accessed 1 August 2016]. [22] A. D. French, N. R. Bertoniere, R. M. Brown, H. Chanzy, D. Gray, K. Hattori and W. Glasser, "Cellulose," Krik-Othmer Encyclopedia of Chemical Technology, vol. 5, pp. 360-394, 17 October 2003. [23] C. Woodings, "Fibers, Regenerated Cellulose," Krik-Othmer Encyclopedia of Chemical Technology, vol. 11, pp. 246-285, 19 December 2003.

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Appendix 1 – Extrusion parameters Table 4. Extrusion parameters for UPM20

Attempt 1 2 3 4 5 6 7 8

Temperature [°C] Speed [1/min] 170 30 175 45 172 33 170 40 175 40 177 45 177 47 180 50

Table 5. Extrusion parameters for UPM30

Attempt 1 2 3 4 5 6 7 8 9 10

Temperature [°C] Speed [1/min] 175 30 180 35 178 30 170 30 172 30 170 30 175 30 170 30 175 33 177 35

Table 6. Extrusion parameters for UPM40

Attempt 1 2 3 4 5 6

Temperature [°C] Speed [1/min] 180 35 185 40 187 40 187 45 187 50 190 50

Table 7. Extrusion parameters for UPM50

Attempt 1 2 3 4 5 6

Temperature [°C] Speed [1/min] 180 50 185 35 185 40 187 40 187 45 190 45

31

7 8 9 10 11 12 13

180 185 190 193 193 193 193

40 45 50 55 60 65 70

Table 8. Extrusion parameters for PPC20

Attempt 1 2 3

Temperature [°C] Speed [1/min] 150 30 175 35 180 40

Table 9. Extrusion parameters for PPC30

Attempt 1 2 3 4

Temperature [°C] Speed [1/min] 170 30 175 30 175 40 180 40

Table 10. Extrusion parameters for PPC40

Attempt 1 2 3

Temperature [°C] Speed [1/min] 180 35 185 40 190 45

Table 11. Extrusion parameters for PPC50

Attempt Temperature [°C] Speed [1/min] 1 175 40 2 185 40 3 190 45 4 193 50 5* 180 40 6* 185 40 7* 190 40 * = 2nd time extruding

32

Appendix 2 – Printing parameters Table 12. Printing parameters for polypropylene

Attempt Diameter [mm]

Build plate [°C] 0 40 60 45

Nozzle [mm]

Nozzle [°C]

Infill [%]

0,6 0,6 0,6 0,6

175 175 180 180

15 15 15 15

1 2 3 4

2,1 2,1 2,1 2,1

5

2,1

0

0,6

180

15

6

2,1

60

0,6

180

15

7

2,1

0

0,6

180

0

8

2,1

0

0,6

185

0

9

2,1

0

0,6

187

0

10

2,1

0

0,6

187

80

11

2,1

0

0,6

187

80

12

2,1

0

0,6

187

60

13

2,2

0

0,6

187

0

14

2,2

0

0,6

187

0

15

2,2

0

0,6

187

0

Print speed [mm/s] 15 15 15 15

Base

Glass+glue Glass+glue Glass+glue Plastic film+glue 15 Plastic film+glue 15 Plastic film+glue 15 Rough thick PP plastic film 15 Rough thick PP plastic film 15 Rough thick PP plastic film 15 Rough thick PP plastic film 25 Rough thick PP plastic film 35 (100% Rough thick  60%) PP plastic film 15 Rough thick PP plastic film 15 Rough thick PP plastic film 15 Rough thick PP plastic film

33

16

2,2

0

0,6

187

0

20

17

2,2

0

0,6

187

0

20

Nozzle [mm]

Nozzle [°C]

Infill [%]

0,6 0,6 0,6 0,6 0,6 0,6 0,6

185 185 185 185 185 185 185

20 20 20 20 20 20 0

Rough thick PP plastic film Rough thick PP plastic film

Table 13. Printing parameters for UPM20

Attempt Diameter [mm]

Build plate [°C] 185 185 0 90 90 100 0

Print speed [mm/s] 30 30 30 30 30 30 15

1 2 3 4 5 6 7

2+ 2+ 2+ 2+ 2+ 2+ 2+

8

1,84

0

0,6

185

0

15

9

1,97

0

0,6

185

100

15

10

1,97

0

0,6

185

100

15

11

1,94

0

0,6

185

0

15

12

1,9

0

0,6

185

0

15

13

1,9

0

0,6

185

0

15

14

1,79

0

0,6

185

0

15

Base

Glass Glass+glue Glass+glue Glass+glue Glass+glue Glass+glue Rough thick PP plastic film Rough thick PP plastic film Rough thick PP plastic film Rough thick PP plastic film Rough thick PP plastic film Rough thick PP plastic film Rough thick PP plastic film Rough thick PP plastic film

34

15

1,84

0

0,6

185

0

15

16

1,86

0

0,6

190

0

15

17

1,86

0

0,6

190

0

15

18

1,86

0

0,6

190

0

15

Nozzle [mm]

Nozzle [°C]

Infill [%]

0,6 0,8 0,8 0,8 0,8 0,8 0,8 0,8 0,8 0,8 0,8 0,6

185 200 220 220 250 235 235 250 220 235 235 235

20 20 20 20 20 20 20 20 20 10 15 0

Rough thick PP plastic film Rough thick PP plastic film Rough thick PP plastic film Rough thick PP plastic film

Table 14. Printing parameters for UPM50

Attempt Diameter [mm]

Build plate [°C] 100 50 50 100 100 100 100 100 100 100 100 0

Print speed [mm/s] 30 30 30 30 30 30 30 30 30 30 30 15

1 2 3 4 5 6 7 8 9 10 11 12

2+ 2+ 2+ 2+ 2+ 2+ 2+ 2+ 2+ 2+ 2+ 2,03

13

2,03

0

0,6

235

0

15

14

2,1

0

0,6

230

100

15

15

2,1

0

0,6

235

100

15

16

2,1

0

0,6

235

100

15

Base

Glass+glue Glass+glue Glass+glue Glass+glue Glass+glue Glass+glue Glass+glue Glass+glue Glass+glue Glass+glue Glass+glue Rough thick PP plastic film Rough thick PP plastic film Rough thick PP plastic film Rough thick PP plastic film Rough thick PP plastic film 35

17

2,1

0

0,6

235

100

15

18

2,05

0

0,6

230

0

15

19

2,05

0

0,6

235

0

15

20

2,1

0

0,6

235

0

15

21

2,1

0

0,6

235

0

15

22

2,1

0

0,6

235

0

15

Nozzle [mm]

Nozzle [°C]

Infill [%]

0,8 0,8 0,8

210 230 220

15 15 0

Rough thick PP plastic film Rough thick PP plastic film Rough thick PP plastic film Rough thick PP plastic film Rough thick PP plastic film Rough thick PP plastic film

Table 15. Printing parameters for PPC20

Attempt Diameter [mm]

Build plate [°C] 100 100 0

Print speed [mm/s] 15 15 15

1 2 3

2+ 2+ 1,86

4

1,96

0

0,8

235

60

15

5

1,96

0

0,6

235

60

15

6

1,9

0

0,6

235

0

15

7

1,9

0

0,6

235

0

15

Base

Glass+glue Glass+glue Rough thick PP plastic film Rough thick PP plastic film Rough thick PP plastic film Rough thick PP plastic film Rough thick PP plastic film

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Table 16. Printing parameters for PPC30

Attempt Diameter [mm]

Build plate [°C] 100 100 100 0

Nozzle [mm]

Nozzle [°C]

Infill [%]

0,8 0,8 0,8 0,8

220 240 260 245

15 15 15 100

Print speed [mm/s] 15 15 15 15

1 2 3 4

2+ 2+ 2+ 1,86

5

1,86

0

0,8

250

100

15

6

1,86

0

0,6

250

0

15

7

1,86

0

0,6

250

0

15

8

1,86

0

0,6

245

0

15

Base

Glass+glue Glass+glue Glass+glue Rough thick PP plastic film Rough thick PP plastic film Rough thick PP plastic film Rough thick PP plastic film Rough thick PP plastic film

Table 17. Printing parameters for PPC40

Attempt Diameter [mm] 1

1,94

2

1,93

Build plate [°C] 0

0

Nozzle [mm]

Nozzle [°C]

Infill [%]

0,6

240

15

0,6

245

15

Nozzle [°C]

Infill [%]

210

0

Print speed [mm/s] 15

15

Base

Rough thick PP plastic film Rough thick PP plastic film

Table 18. Printing parameters for PPC50

Attempt Diameter [mm] 1

1,96

Build plate [°C] 60

Nozzle [mm] 0,8

Print speed [mm/s] 15

Base

Rough thick PP plastic film

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2

1,96

35

0,8

240

0

15

3

1,92

0

0,6

240

0

15

4

1,92

0

0,6

240

0

15

Rough thick PP plastic film Rough thick PP plastic film Rough thick PP plastic film

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Appendix 3 – Dimension comparison Table 19. Dimensions of 3D model using polypropylene

Attempt 8 9 11 12 15 17

Dimensions Cura (X×Y×Z) [mm] 15,0 × 25,0 × 10,0 15,0 × 25,0 × 10,0 17,0 × 27,0 × 12,0 25,0 × 35,0 × 20,0 27,0 × 47,25 × 20,251 27,0 × 47,25 × 20,251

Dimensions printed (X×Y×Z) [mm] 15,35 × 25,21 × 10,25 15,63 × 25,39 × 10,01 17,03 × 27,06 × 11,60 24,89 × 34,70 × 20,18 27,07 × 47,09 × 20,50 27,27 × 47,32 × 20,51

Table 20. Dimensions of 3D model using UPM20

Attempt 6 7 8 10 17 18

Dimensions Cura (X×Y×Z) [mm] 25,0 × 25,0 × 10,0 15,0 × 25,0 × 10,0 17,0 × 27,0 × 12,0 25,0 × 35,0 × 20,0 27,0 × 47,25 × 20,251 27,0 × 47,25 × 20,251

Dimensions printed (X×Y×Z) [mm] 25,10 × 25,10 × 10,15 15,17 × 25,16 × 10,16 17,01 × 27,05 × 11,96 25,10 × 35,39 × 20,32 27,24 × 47,88 × 20,41 27,14 × 47,59 × 20,66

Table 21. Dimensions of 3D model using UPM50

Attempt 2 3 4 5 6 7 8 9 10 11 12 13 16 17 22

Dimensions Cura (X×Y×Z) [mm] 20,0 × 20,0 × 10,0 20,0 × 20,0 × 10,0 20,0 × 20,0 × 10,0 20,0 × 20,0 × 10,0 20,0 × 20,0 × 10,0 20,0 × 20,0 × 10,0 20,0 × 20,0 × 10,0 20,0 × 20,0 × 10,0 20,0 × 20,0 × 10,0 20,0 × 20,0 × 10,0 15,0 × 25,0 × 10,0 17,0 × 27,0 × 12,0 20,0 × 30,0 × 15,0 25,0 × 35,0 × 20,0 27,0 × 47,25 × 20,251

Dimensions printed (X×Y×Z) [mm] 20,65 × 20,65 × 10,35 20,66 × 20,68 × 10,33 20,66 × 20,66 × 10,30 20,64 × 20,64 × 10,33 20,48 × 20,48 × 10,38 20,47 × 20,47 × 10,42 20,40 × 20,40 × 10,41 20,44 × 20,44 × 10,41 20,46 × 20,46 × 10,47 20,40 × 20,40 × 10,45 15,51 × 25,54 × 10,26 17,29 × 27,54 × 12,04 20,01 × 30,16 × 15,25 25,58 × 35,48 × 20,41 27,51 × 47,85 × 20,44

Table 22. Dimensions of 3D model using PPC20

Attempt 3 4 5

Dimensions Cura (X×Y×Z) [mm] 15,0 × 25,0 × 10,0 25,0 × 35,0 × 20,0 25,0 × 35,0 × 20,0

Dimensions printed (X×Y×Z) [mm] 15,43 × 25,18 × 10,25 25,36 × 35,27 × 20,37 25,39 × 35,19 × 20,32

39

6 7

27,001 × 47,25 × 20,25 27,001 × 47,25 × 20,25

27,41 × 47,68 × 19,66 27,36 × 47,69 × 20,52

Table 23. Dimensions of 3D model using PPC30

Attempt 4 5 8

Dimensions Cura (X×Y×Z) [mm] 25,0 × 35,0 × 20,0 25,0 × 35,0 × 20,0 27,001 × 47,25 × 20,25

Dimensions printed (X×Y×Z) [mm] 25,93 × 35,93 × 20,24 25,46 × 35,37 × 20,17 27,37 × 47,64 × 20,43

Table 24. Dimensions of 3D model using PPC40

Attempt 1

Dimensions Cura (X×Y×Z) [mm] Dimensions printed (X×Y×Z) [mm] 25,0 × 35,0 × 20,0 25,63 × 35,48 × 20,24

Table 25. Dimensions of 3D model PPC50

Attempt 2 4

Dimensions Cura (X×Y×Z) [mm] Dimensions printed (X×Y×Z) [mm] 15,0 × 25,0 × 10,0 15,73 × 25,68 × 9,34 27,0 × 47,5 × 20,251 27,41 × 47,83 × 20,53

40

Appendix 4 – Materials

a)

b)

c)

Figure 17. Granulates for extrusion where a) and b) is UPM and c) is pure polypropylene

Figure 18. Polypropylene and cellulose mixture (PPC)

41

Appendix 5 – Pictures from extrusion

Figure 19. Small twin-screw extruder

Figure 20. UPM filaments produced from the small extruder and pure polypropylene filaments produced using the bigger extruder

Figure 21. Big extruder

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Appendix 6 – Pictures from 3D printing

Figure 22. 3D model being printed on a thick, roughed PP film

Figure 23. Printing attempt using polypropylene

Figure 24. Finished 3D model printed with polypropylene

43

Appendix 7 – 3D models made of different substances

Figure 25. 3D printed models of UPM20

Figure 26. 3D models printed using UPM50

Figure 27. Different 3D models made of PPC20

44

Figure 28. 3D printed models made of PPC30

Figure 29. 3D model to the right is made of PPC40 and the other two is made of PPC50

Figure 30. Printed models of polypropylene

45