Acetone-Vapor Polishing

Transcription

1 Acetone-Vapor Polishing Eman Aljabr March 28, 2014 Acetone-Vapor Polishing Eman S. Aljabr March 28 th, 2014

2 Executive summary: While 3D printing was first used by industrial companies for such applications as rapid manufacturing and prototyping, recently many hobbyist and enthusiasts started building their own 3D printers for practical household applications, such as gear. However, no matter how good of printer is being used, the produced model usually looks very rigid and have sharp edges. The purpose of this application note is to address smoothing the produced model with minimal cost using Acetone-vapor. Key words: Acrylonitrile Butadiene Styrene

3 Introduction: Design team 8 is designing a specialty 3D tactile graphic printer for blind students at MSU. This printer should be able to print 11 x 17 inches durable maps and graphs that could help blind students go around campus. This specialty printer will use Acrylonitrile Butadiene Styrene (ABS) as a filament to produce the displays. ABS is considered superior to other plastics for its hardness, gloss, toughness, and electrical insulation properties. Also, its glass transition temperature makes it ideal as a filament; it is low enough to be safely attainable with the standard extruders but high enough to reduce distortion at slightly elevated temperatures. However, for anyone who has ever tried using ABS or any other filament to print a 3D model knows that the results are not always smooth, regardless of the quality of the printer that is being used. Produced maps will have sharp edges, and may crack skin on fingers with repeated use. Hence, maps should be treated before being used by blind students. Objective: Currently, there are several methods to smooth the surface of a 3D printed model. However, one major goal of this application note is to accomplish this task with minimal to no cost at all using materials available at home. Thus, this application note will address Acetonevapor method to polish 3D models. Methods: Method one: Materials: To use this method, the following materials are needed: Heatbed

4 Figure 1. Heatbed Glass Jar (see figure 2) Figure 2. Glass Jar Acetone Figure 3. Nail-Polish Remover A rectangular piece of cardboard Figure 4. Cardboard box

5 Foil Paper Figure 5. Foil Paper Steps: Please note that having a 3D printer eliminates the need for a heatbed as it is part of the machine and can be used for the purpose of this application note. As can be noticed, the rest of the items are readily available in most homes. 1. Creating the base: Out of the rectangular piece of cardboard, create a base for your 3D model. This can be done by simply folding down two ends of the cardboard so it no longer lays flat on ground. Then, cover the base with foil paper. This ensures that the Acetone and heat won t frail the base. 2. Place few drops of the Acetone in the jar. Note that this depends on the model size and the desired amount of smoothness. Figure 6 shows the result of treating the same model with different amounts of Acetone. 3. Place 3D Model on base (step 1) then place it inside the glass jar. 4. Place glass jar on heatbed. 5. Observe the 3D model in the jar as the Acetone starts to evaporates, in a matter of seconds the model will start to shine and it will look smoother. There s no formula for calculating the time the model needs to be in the jar. The model should be removed when it reaches the desired amount of smoothness or when the Acetone evaporates fully. Leaving it for too long may cause some significant features to fade. When the desired outcome is reached, remove the jar from heatbed. Caution: Glass jar may be hot! 6. Leave the model for few minutes to dry.

6 Results: Figure 6. Acetone Vapor Treating From left to right: Original ABS model Smoothed with 2ml of Acetone Smoothed with 4ml of Acetone Smoothed with 6ml of Acetone Method two: In the case when the user cannot obtain a 3D printer, a similar method can be followed that does not require a heatbed. Materials: A covered container (e.g. glass jar or a lunch box). Cardboard Foil Paper Acetone Steps: 1. Create the base in the same manner as in method one.

7 2. Place few drops of the Acetone in the container. Again, please note that this depends on the model size and desired amount of smoothness. 3. Place 3D Model on base (step 1), then place inside the container. 4. Cover the container and wait until Acetone evaporates or desired smoothness achieved. 5. Leave model for few minutes until it is dry. Results: This method should yield similar results. However, it takes a considerably longer amount of time. Figure 7 shows a comparison between the two methods. The model on the left was treated using method one while the other two were treated using method two. Conclusions: Figure 7. Treating model Acetone Acetone ((CH 3 ) 2 CO) is considered a great solvent for many types of plastics. Exposing Acetone vapor to an ABS model causes its surface to dissolve. Both addressed methods perform well in polishing ABS 3D printed models. While method one is considerably faster, method two may be cheaper when the user does not own a 3D printer or a heatbed. Regardless, both methods require paying attention to the model while in the smoothing process. Otherwise, the model

8 could be over smoothed and some important features may be lost. Observing is a key for the success of polishing the surface of the 3D model.

9 Works Cited: Acetone. n.d. 9 March 2014 < Acrylonitrile butadiene styrene. n.d. 9 March 2014 < Petrus. Hot plate stirrer to dissolve PLA. 24 April March 2014 < Smooth surfaces of ABS 3D printed parts with acetone vapor. 26 February March 2014 <