Ncceb 2019 paper 21 PDF

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Ncceb 2019 paper 21...

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PLUSTECH: A Polyethylene Terephthalate Filament Maker with Ender III 3D Printer Princess M. Badua

Ashley Mae O. Bautista

Ruth C. Navarro

Lorma Colleges Carlatan, City of San Fernando, La Union, Philippines +639456180743

Lorma Colleges Carlatan, City of San Fernando, La Union, Philippines +639655388959

Lorma Colleges Carlatan, City of San Fernando, La Union, Philippines +639498038681

[email protected] [email protected]

[email protected]

Maria Chabelita D. Nual

Ellaine Michelle N. Olpindo

Carolyn H. Turalba

Lorma Colleges Carlatan, City of San Fernando, La Union, Philippines +639663693380

Lorma Colleges Carlatan, City of San Fernando, La Union, Philippines +639567820583

Lorma Colleges Carlatan, City of San Fernando, La Union, Philippines +639070376779

[email protected] ellainemichelle.olpindo@lorma. edu

ABSTRACT Plastics can be spotted everywhere as it is now utilized as an alternative to materials such as wood, paper, metal, and glass. Polyethylene Terephthalate (PET) is a type of plastic that is light, clear and sturdy which is mostly used for consumer products such as water and carbonated drinks. PET is a plastic that can be recycled completely which can be converted into different useful products. One of which is a 3D printer filament that has equal toughness as the Acrylonitrile Butadiene Styrene (ABS) and is as easy to use as the Polylactic Acid (PLA). PlusTech is a machine that creates 3D printer filament from PET water bottles which is crafted using 5 major components: the shredder, pigment tank, mixer, extruder, and spooler. The process involves the collection of empty purified or mineral water bottles (350mL) drying and cutting it into half, vertically. Then, feeding the plastics into the shredder, adding and mixing plastic pigment or not, extruding and spooling the created filament. This design project is greatly influenced by the advancement of technology that helps students, instructors, and 3D printing enthusiasts to be able to print 3D models using recycled plastics without spending too much on filaments.

Keywords 3D Printing; 3D Printer Filament; Filament extrusion; Recycled PET bottles

1. SITUATIONAL ANALYSIS Plastic is being used on a daily basis as almost everything today is made up of it. It has already become an important part to all of us due to the increase of number in our population and technology advancement. According to Miller et al. (2014) [1] from the article of Challenges and Alternatives to Plastics Recycling in the Automotive Sector, Plastics are increasingly a preferred material choice in designing and developing complex, consumer products, such as automobiles, because they are moldable, lightweight, and are often perceived to be highly recyclable materials.

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According to PET Resin Association (2015) [2] from the article of An Introduction to PET, PET (also abbreviated PETE) is short for polyethylene terephthalate, the chemical name for polyester. PET is a clear, strong, and lightweight plastic that is widely used for packaging foods and beverages, especially convenience-sized soft drinks, juices and water. PET is a very energy-efficient packaging material. Although its raw materials are derived from crude oil and natural gas, it enjoys a very favorable sustainability profile in comparison to glass, aluminum and other container materials. Basing on the assertion by Razali and Ishak (2016) [3] from a study on Utilization of Waste PET bottle fibre in concrete, the plastic usage is increasing day by day. PET is commonly used for carbonated beverage and water bottles. This induced an environmental issue as waste plastic bottle are difficult to biodegrade and involves process either to recycle or reuse. PET which is numbered with "1" refer to the resin identification code to identify materials used to make the origin of the plastic. This bottle is often not coloured and have a high penetration rate of light compared to other plastics. While PET is not decomposable, it is a known material since it can be recycled completely. It is recycled at an industrial scale. One of the converted products of the recycled PET is a 3D printer filament. A 3D filament is a 3D printer plastic that is used to make threedimensional printing. According to Armando (Unknown) [4] from his own article entitled as PET Filament: Waterproof and Food Safe Material Plastic for 3D Printing, PET filament is a great filament to use for 3D printing. It has the same strength as Acrylonitrile Butadiene Styrene (ABS) but it is as easy to use as Polylactic Acid (PLA). It is waterproof and is safe to use for food. PET filament 3D printing does not easily warp, unlike ABS. It has no fumes or odors during the process of printing. This material may not be biodegradable, but it is 100% recyclable.

According to Techfortrade (2016) [5] from Thunderhead Filament Extruder – PET Filament Development Technical Feasibility Report, PET is a straightforward choice when the goal is to produce 3D printer filament from post-consumer waste plastic. PET is an ideal plastic in 3D Printing. It has low amount of shrink like PLA and yet is tough like ABS. The only problem is that it is difficult to extrude into filament on a small scale. The challenges in extruding PET is that the plastic crystallizes if it is cooled slowly. When it crystallizes, it becomes very brittle, like glass. Another difficulty is that PET is hygroscopic which means that it absorbs water from its surroundings. Also, PET has low melt strength and low viscosity at the melting point which means that it does not resist being stretched once the plastic is melted. Then, the polymer being extruded is in the form of bottle flake rather than pellets wherein it does not have the same advantage like pellets which are uniform in size and shape. The PET plastic is very easy to find anywhere and everywhere all over the world which can be used for printing 3D models. But through the process of creating the right quality of filament, there were lots of challenges that were observed and undergone. The polymer, PET plastic must be cooled quickly with the use of water bath in order to prevent crystallization. Before processing, the plastic must be dried immediately so that the presence of moisture in the plastic is eliminated for a successful melting process. Then, the extrusion of the plastic flakes must be done vertically because of its consistency when it is melted. Also, since bottle flakes are used and not pellets, wherein the sizes and shapes of the flakes vary, the flow of the extrusion will not be smooth and easy when the extruder is positioned horizontally. Based on the statement of Razvan, et al. (2014), [6] many CNCs are controlled using a special programming language named, GCode. Such program consists in a sequence of commands, such as for head movement on different axis with different speeds and interpolations, start/stop the spindle, set the various machining parameters, change the active tool, etc. The G-Code is much simpler compared with a high-level programming language since its actual form does not have decisions, variables or loops. The GCode can also be developed manually or it can be generated automatically.

2. DESIGN PROCEDURES 2.1 Conceptual Framework

Figure 1. Conceptual Framework of PlusTech: Filament Maker It shows the conceptual framework of the project. The project has two main processes involved, one for the filament maker and the other for the 3D Printer. The filament maker takes an input of Polyethylene Terephthalate plastic bottles with a maximum height of 18 centimeters and a maximum diameter of 3.81 centimeters. With its plastic label and the hard part located on top removed, it then has a net mass of 5.5 grams. The input of plastic bottles will then be shredded by the

shredder of the filament maker which produces tiny bits of plastics. It may then be added with pigment through the pigment hopper depending on the preferences of the user, mixed and then melted and extruded into filament. The filament being extruded is then spooled in the spooling section of the machine. The output is now a Polyethylene Terephthalate (PET) 3D Printer filament which is then used by the 3D Printer.

Figure 2 Conceptual Framework of PlusTech: Ender III 3D Printer It shows the conceptual framework of the Ender III 3D printer that takes the filament made up of polyethylene terephthalate with a diameter of 1.75 millimeters as the input and then convert it into a 3D-printed object.

2.2 Schematic Diagram

Figure 3. Schematic Diagram of the Filament Maker The figure shows the connection of the Arduino Mega 2560 microcontroller which acts as the main controlling unit of the machine. First and foremost, each stepper motor is connected to its respective A4988 Stepper Motor Driver, connected with capacitor to reduce the noise, which is further connected to the digital pins of the microcontroller. As for the stepper motor for the filament extrusion process, the corresponding STEP pin is connected to Digital Pin 13 and its DIR pin is connected to Digital Pin 12. For the first stepper motor of the spooling process which distributes the filament throughout the spool holder, its driver’s STEP pin is connected to Digital Pin 11 and its DIR pin to Digital Pin 10. For the last stepper motor which turns the spool holder, its driver’s STEP pin is connected to Digital Pin 9 and its DIR pin is connected to Digital Pin 8. On the other hand, the servo motors are connected to Digital Pins 7 for Pigment Tank and 6 for the Mixer Base. For the two DC motors driven by a Dual H-Bridge L298N Motor Driver, the one for the mixer is connected to Digital Pins 5 and 4, and the one for the cooling fan is connected to Digital Pins 3 and 2. The driver is connected to a 12V source and the GND pin to the ground. Next, weight sensor’s driver, HX711, is connected to Digital Pin 22 for the receiver pin (DO/RX) and Digital Pin 23 is connected to the transmitter or clock pin (CK/TX). The weight sensor itself is connected to E+ for the Red Wire, E- for the Black Wire, A- for the White Wire, and A+ for the Green Wire. For the

relay module which serves as the switch for the heating element, its Input (IN) Pin is connected to Digital Pin 38 and the GND and VCC pins are connected to ground and 5V, respectively. Then, the NO (Normally Open) connector to a leg of the heating element and the COM (Common Ground) is connected to a leg of AC Power Supply and the other leg to the remaining leg of the heating element. As for the limit switch, a 10kΩ resistor is connected to its NO (Normally Open) connector and is connected to Digital Pin 40 forming a junction. Then, its COM connector is connected to the ground. Last are the sensors – Thermistor Module, LDR Module, and Sharp IR Sensor – being connected to Analog Pins. A0 is connected to the input (A0) pin of the Thermistor Module, A1 is connected to the input (IN) pin of the LDR Module, as well, and lastly, A2 is connected to the Sharp IR Sensor.

needs. Each version that was made went through a series of testing for the researchers to identify the particular error and failures of the design project. With the inclusion of testing, it has led the researchers to further study the project and has also supported the improvement of the design project.

2.3 Use Case Diagram Figure 5. Position of the 5 major components of the Filament Maker The figure shows that the shredder, pigment tank, mixer and extruder are respectively positioned vertically in one place in order to achieve an easy flow of process using the gravitational force. In that way, lesser components were used in the filament maker. One of the important factors to consider is the extrusion process wherein the PET plastic pieces were melted to form a filament. The PET has a consistency which is closely relative to the thickness of honey when melted. Also, it has a low rate of viscosity at the melting point that is why the extruder must be in a vertical set up. While the spooler which serves as the last process in filament making was located at the right side of the machine. Its placement was suited to be in that way so that it would align with the user’s chest level and for easy grabbing of the spooled filament after completing all the process.

Figure 4. Use Case Diagram The figure shows the different capability of the user when operating the machine. First and foremost, the user can turn on or off the machine. If the machine is turned on, he can now input plastics. After certain processes, he will then be prompted whether he wants to add color or not. If the user chooses to add color, he should press the proper button then a suggested amount of pigment will be displayed on the monitor which the user must input. Then, it will undergo some processes again until the filament is ready to use which will be displayed on the touchscreen monitor. The user then connects the filament to the printer and may now open his 3D model file, load it and generate its G-Code through a G-Code Generator which in this case is Slic3r. He may now load and print the G-Code file with a 3D printing software such as Pronterface. The user can print from the computer of SD card. In cases where the user wants to create another spool of filament with different color, he may always replace the spooler in the machine.

3. RESULTS AND DISCUSSIONS 3.1 Design Structure The machine has five (5) major components which are the shredder, pigment tank, mixer, extruder and spooler. Throughout the progression of this design project, the PlusTech: A Polyethylene Terephthalate Filament Maker with Ender III 3D Printer had undergone the creation of different versions in every process in order to produce a functional and efficient device to cater the user

Figure 6. Actual Image of Ender III 3D Printer It shows the assembled Ender III 3D printer. Creality Ender-3 3D Printer uses FDM (Fused Deposition Molding) or Fused Filament Fabrication for its molding technology which enables the creation of 3-dimensional printed models. This kind of process uses a thermoplastic filament which is melted and then extruded for it to print layer by layer until it creates a three-dimensional object. The machine size is 440 x 410 x 465mm while its printing size is 220 x 220 x 250mm. Its printing speed caters 180mm/s with the use of 1.75mm any type of filament such as PLA, ABS, TPU wood copper gradient etc. The nozzle diameter of the printer is 0.4mm which can print a layer thickness of 0.1-0.4mm with a printing accuracy of ±0.1mm. The file format that can be read are STL, OBJ, G-code and it can be online or SD card offline working mode. When printing, its nozzle temperature can be heated up to 260⁰C while the maximum temperature of its heat bed is 110⁰C. Both nozzle and

heat bed temperature can be adjusted depending on what type of filament you’ll be using for 3D Printing. According to the website of Creality Ender 3D Printer Shop [7] Ender-3 adopts innovative V-slot profile and pulley for stable running, low noise, wear resistance and a longer service life. It has an intelligent inductive device which lets you not to worry about power outrage. The power supply protection device and resume printing function take away the user’s fear about sudden power-off during printing and save time and material. It also employs new magnetic self-adhesive platform sticker rather than traditional masking tape and glue for easy model picking-up, excellent adhesion and less printing cost. Excellent hot bed quick heating-up. It has an excellent hot bed to be heated up to 100⁰C in 5 minutes to meet the requirement of quick printing.

The figure shows the last version of the extruder wherein the concept of funnels was applied. Aside from the structure being the channel for transporting the plastic, it also serves as the hopper for easier downward transportation. The design was specially customized for the output of the shredder of more than 1 in2 area. Thus, large plastics bits were better catered and there was better extrusion. As shown, a wood spacer was placed in order not to heat the whole channel.

Figure 10. 3D Printer Heating Cartridge The figure shows the last version of heating element which involves the use of 3D printer heating cartridge. With this type, the plastics were melted better.

Figure 7. The Plastic Shredder It shows the actual version 3 of the shredder composed of 13 blades and 12 spacers both of 4mm thickness. Its blades are two-teethed having a total outer diameter of 4.5 inches while the spacers are 2 inches in diameter. The shredder has a width of 14.3 cm, length of 12.5 cm, and a height of 12 cm. With these dimensions, bottles that can hold up to 350 mL of water are better catered than larger ones. If the latter is available, the user may always cut such in order to feed the plastic properly into the shredder.

Figure 11. Measuring the Time to Reach Melting Point The figure shows the time it takes for the heating element to melt the plastics through the use of stopwatch. As seen in the figure, the heating element was being preheated as implied by the time in the stopwatch. Heating continued and a time of 4 minutes, 17 seconds and 30 milliseconds was acquired.

Figure 8. Shredder Output The figure shows the output of the shredder. Such plastic bits has areas not less than 1 in2.

Figure 9. Funnel-type Channel

Figure 12. Serial Monitor Displaying the Analog values at Plastic Melting Point It shows the serial monitor displaying the analog values, measured by the thermistor at every 250 millisecond, when the plastics have reached its melting point. The values acquired were the maximum analog value of 1023. Hence, the plastics melt at the maximum value given off by the heating element. Though this usually means that the heating element had already reached its maximum, the shredded plastics still got overly heated and began to blacken as if

overcooked. The heating element, therefore, has to be switched on or off periodically to avoid such occurrence. Repeating the procedure, it was observed that at analog value of 989, the shredded plastics have significantly curled up and were about to be melted. Therefore, the heating element preheats until the thermistor reads 1023 prompting then the extruder motor to rotate then the heating element turns off and when the thermistor has read a value of 989, the heating element turns on again.

3.2 Component Testing Table 1. Power Source Specification of the Filament Maker COMPONENT AC Motor Arduino Mega 2560 Cooling Fan DC Motor Heating Element Raspberry Pi 3 B+ Servo Motor (Mixer Base) Servo Motor (Pigment Cover) Stepper Motor (Distribution) Stepper Motor (Extrusion) Stepper Motor (Spooling)

VOLTAGE 5V

CURRENT 50mA

POWER 1305 W 2.5 W

12 V 12 V 4.98 V 4.8 V

0.5 A 10 A 46.5mA 550 mA

6W 120 W 40 W 2.31 W 2.64 W

4.8 V

550 mA

2.64 W

12 V

1.5 A

18 W

12 V

1.5 A

18 W

12 V

1.5 A

18 W

Figure 14. Triggering Python UI through a Component The figure shows a component, limit switch, that prompts the user interface to go to the next frame. Aside from the component being connected to the Arduino Mega 2560, it was also connected to the Raspberry Pi GPIO pin to enable its triggering capability. Since the component uses a pull-up resistor, its state is then TRUE when it is not pressed (when it has not detected a filament), and FALSE when it is. The first figure shows that there is no detected filament, thus printing the string, “Button NOT Pressed.” On the other hand, the second figure shows that there is a filament detected, hence, printing a string, “Button Pressed.” The same concept applies on all components that trigger...