Fluent Essays

1 Assessment of Rapid Prototyping Technologies for Business Needs Prepared for: Jody Shine Prepared by: Christopher LaPonsie Nolan Rinck Grant Erbes Kyle Oberly August 9th, 2021 Abstract Various 3D printer technologies and materials are evaluated based on recent sources of secondary and primary information to build a case for recommending two different 3D printers and materials. Understanding the needs of the application is imperative to success in selecting a 3D printer, because different applications will have different requirements. Some parts may require fine details for functional purposes, while others may only require fine details for esthetics. Furthermore, some prototype parts may require rigidity in terms of tensile strength or impact strength. In this paper, we evaluate which technologies are best for tensile strength, impact strength, resolution and dimensional accuracy, cost effectiveness, and general-purpose applications. Assessment of Rapid Prototyping Technologies for Business Needs Introduction Background For those who may not know what 3D printing technology is, Flynt (2018) describes it as a process similar to a regular inkjet printer, but instead of going through one print cycle, 3D printers go through many print cycles stacking material on top of the previous layer until a finished prototype is formed. 3D printing technology has been around since the 1980s and was originally used as an affordable way to develop prototypes in the manufacturing industry. 3D printing technology goes by several names including stereolithography (SLA), additive manufacturing, and rapid prototyping (Flynt, 2018). The first stereolithography machine was patented in 1986 by an American inventor named Charles Hull. It was the first device to print physical parts based on computer generated files and was the first step in the development of widely available 3D printing technology (Flynt, 2018). By the early 2000s, 3D printing technology was being developed beyond the manufacturing industry into the healthcare industry. As unusual as it may sound, the 2000s brought about the technology to 3D print human organs including kidneys, bladders, and blood vessels. Along with the healthcare industry, the general public began to adopt 3D printing technology for personal projects. As time as led up to now, the cost of 3D printers has decreased, the accuracy has improved, the user interface has become easier to navigate, designs have become easier to produce, and 3D printing technology continues to prove itself to be an extraordinarily useful tool in the production environment (Flynt, 2018). There are many different types of 3D printing technologies with different functions. Shahrubudin (2019) outlines several including binder jetting, directed energy deposition, materials extrusion, materials jetting, powder bed fusion, and sheet lamination. Binder jetting involves a liquid binding agent which is selectively positioned to join powder particles. This method is popular because it is simple, fast, cheap, and can be used to print very large products. Directed energy disposition involves repairing existing components by directing the filament nozzle to specific angles to fill in gaps in damaged parts. This method is beneficial for maintenance of parts, but is not necessarily viable for creating completely new products. Materials extrusion is a process in which thermoplastic is heated to semi-liquid form and is deposited along a predetermined path to create the shape of the given layer. Each layer is stacked upon one another until the finished product is complete. This method is very popular because it is inexpensive and viable for use by hobbyist 3D printer owners. Materials jetting is a process in which drops of material are deposited onto the surface and are hardened by ultraviolet light. This method results in a very smooth finish which is beneficial for ceramic products. Powder bed fusion involves an electron beam to melt the material powder together. This method can create metal, plastic, and ceramic objects with fast speed and high accuracy. Lastly, sheet lamination is a process in which sheets of material are cut out into their various shapes based on their given layer and then fused together one on top of the other. This opens the ability to create complex geometrical shapes at low cost (Shahrubudin, 2019). Our study focuses on the area of 3D printing known as rapid prototyping. Gurr (2018) defines rapid prototyping (RP) as a subcategory of 3D printing specializing in the rapid creation of physical model prototypes at low cost. The rapid prototyping process has been around since the late 1980s and has steadily become more refined with time. The primary application of rapid prototyping technologies is in the creation of custom-made parts to be used as prototypes. Rapid prototyping typically takes place in the early stages of product development and allows designers to experiment with ideas to identify the most effective design for their needs. This provides a reasonably fast way for designers to rule out designs without the high cost of developing a finished product. 3D filament material is economically favorable for prototyping compared to production molds (Gurr. 2018). Determining the most efficient rapid prototyping has been a huge problem over time due to limited knowledge and understanding of rapid prototyping technology and techniques. Rapid prototyping is an important subject in technology particularly in relation to the development of three-dimensional computer-aided designs. One of the main types of rapid prototyping is additive manufacturing which refers to the industrial production name for 3D printing. In the assistive manufacturing process, the designers are allowed to create three-dimensional geometry directly from the CAD data. This is attained through slicing geometry into finite layers and fabrication of the prototype one layer at a time. With the increased prevalence of additive manufacturing among organizations across the world, there has been establishment of common terminology and standards to enhance quality of the products manufactured under the additive manufacturing process. In determining additive manufacturing and the respective prototyping technology, there has to be a clear definition of different classifications of additive manufacturing technologies. Among the classifications include material jetting which refers to the process of selectively depositing droplets of build material onto a build bed in developing a three-dimensional object (Hofmann et al, 2019). Also, there is material extrusion which refers to the process of pushing a spool of material through a heated nozzle in the creation of the 3D object in additive manufacturing. In addition to the classifications include the power bed fusion and the directed energy deposition. Directed energy deposition requires the additive manufacturing process to have a focused energy source such as electron bean or plasma arc. In all the classifications of additive manufacturing, there has to be optimal selection of the technology otherwise the outcome and the additive manufacturing process will be affected adversely. In determining the most cost-effective prototyping, there as to be evaluation of major contributions or quality attributes in the manufacturing process and the contribution of each of the attributes to the overall process. After identification of the sub-processes, an assessment of the most appropriate technology to use is done to determine the technology to be adopted in enhancing the most efficient prototyping process in the additive manufacturing process. Among the quality attributes used in determining the most effective prototyping process include impact strength, tensile strength resolution and tolerance, cost-effectiveness and general purpose applications (Dietrich et al, 2017). Over the years, additive manufacturing has led to a boost in manufacturing quality, time, and total cost. It is vital to note that most business enterprises and consumers have stimulated and accelerated 3D printing technology. Some research has been done to establish the manufacturing and security challenges in 3D printing. In addition, there are various benefits associated with additive manufacturing. First, it is essential in customizing products. It is significant to note that manufacturers face the pressure of meeting multiple market needs and demands attributed to consumers. To counter this challenge, manufacturers integrate Ender 3D printing technology in the production of goods. Consequently, this leads to product tailoring to fit various consumers. In the long run, customization attributed to additive manufacturing would boost the strength of a product in the market and improve customer satisfaction. 3D printing has also led to the localization of production by manufacturers. This has led to a scenario where businesses localize production in closer proximity to markets and consumers. In addition, the interaction between consumers and businesses enhancing localized manufacturing techniques through additive manufacturing has been promoted. Minimized logistics is another benefit of using 3D printing technology. The supply chains and world-spread manufacturing techniques have been enhanced through the use of additive manufacturing. Research on 3D printing technology has also led to an examination of potential risks that might accrue. The change of printing orientation is one of the biggest risks. On top of this, internal defects from additive manufacturing would pose a huge risk. However, studies have shown that utilizing finite element examination and ultrasonic inspection would go a long way in establishing potential risks. It can be noted that poor product quality and security problems are a huge challenge in enhancing 3D painting technology (Zeltmann, 2016). Research deeply delved into understanding the adoption of 3d printing technology in manufacturing by coming up with a survey examination. Over the past decade, most research work anchored on 3D painting technology has discussed the likelihood of additive manufacturing to enhance the optimization of tasks and supply chain effectiveness. The study found that there existed a negligible amount of literature anchored on the elements that affect 3d printing technology in manufacturing. Further, the study sought to first address how a companys management would impact the speed of adopting additive manufacturing techniques. It is important to note that a companys perception of additive technology would play a role in determining its adoption. The study concluded that the complexity of the top management of companies concerning the adoption of 3D painting was very conflicting. In a nutshell, the intention-to-adopt additive manufacturing technique would solely lie in the hands of a companys top management, which would hinder innovation. Perceptions form a big risk to the adoption of 3D printing technology in companies (Schniederjans, 2017). Binder 3D printing technology has immensely been adopted in China, which is the worlds hub for manufacturing. A study was carried out to explore the problems experienced in creating and utilizing Binder 3D printing technology and emphasized China. Obstacles were uncovered. The study found that many companies in China understood the benefits of adopting 3D printing technology but had not integrated it into their production and manufacturing systems. It noted that the supply chain systems of China had not adopted 3D printing technology. The problem of intellectual rights and counterfeit posed a threat to the adoption of 3D printing technology in China. The research recommended developing robust legal frameworks to aid the in-licensing of 3D printing technologies (Chan et al., 2018). Binder jetting technology allows the designers to printing of more than one part at a time. The technology uses micro-fine droplets of a liquid which are sprayed on a powder bed to bond the particles of the powder together forming a layer of the part (Ziaee & Crane, 2019). Research Methods The research was conducted using the document analysis method in which the researchers collected data from various secondary sources particularly journals and video sources. The sources were searched based on the relevance to the topic and an appraisal of the sources was done. This was done to enhance validity and reliability of the research sources in contributing to the conclusions and interpretations made from the study findings. The search was narrowed to the specific topic asked in the research question. Results Which technology offers the best resolution and tolerances? Prototype parts with fine details will require a printer with a fine resolution to reproduce. Many applications for prototyping may require not fine details, but others will. For instance, rigid strength may the most important feature of a mounting bracket, while dimensional accuracy and detail may be the most important feature for a test fixture that must be precisely located. Sometimes fine features are for esthetics only, but fine features can have a functional purpose as well (Mou & Koc, 2019). In the latter case, a 3D printer with finer resolution and dimensional accuracy is preferred. 3D printer resolution will obviously vary depending on technology and material. It may be less obvious, however, that resolution also varies within the same machine in different axes of printing. For example, Ultimaker 3 Extended, which is an FDM printer, has a resolution of 12.5µm in the XY plane and a resolution of 200µm in the Z direction (Mou & Koc, 2019). Z resolution varies by 3D printing technology (see Figure 1). Fused Deposition Molding (FDM) printers are the most cost effective and widely used (Mou & Koc, 2019). FDM printing extrudes thermoplastic onto a build surface, one layer at a time (Shahrubudin, Lee, & Ramlan, 2019). In testing this technology with a standard part, Mou and Koc (2019) found that while FDM printers produced, “acceptable dimensional accuracy, FDM prints were characterized by a rough surface finish and a poor edge sharpness” (p. 922). However, post processing the part can improve the surface finish (Mou & Koc, 2019). This may include sanding or using a chemical solvent to smooth the surface. In terms of dimensional accuracy, the parts may end up thicker in the Z-axis due to build plate adhesion layers, which are required to make sure the part stays firmly in place while printing (Mou & Koc, 2019). FDM printers offer a better solution in the XY plane than the Z plane. The Ultimaker 3 Extended, for example, has an XY resolution of 12.5µm and layer resolution (Z) of 200µm (Mou & Koc, 2019). Compare this with the Formlabs Form 3, which is an SLA printer with an XY resolution 25µm and a layer resolution of 25µm (Formlabs, 2021). While FDM can produce dimensionally accurate parts and acceptable resolution in the XY plane, it suffers compared to other technologies in the Z plane. Additionally, dimensional accuracy of FDM prints will vary with process parameters. For example, one study concluded that FDM parts printed with PLA had the least dimensional deviation when printed at a temperature of 200˚C to 230˚C, while Polycarbonate printed best between 250˚C and 280˚C (Cekic, Muhamedagic, Begic-Hajdarevic, & Djuzo, 2020). Stereolithography (SLA), is a 3D printing technology that uses photopolymerization to cure polymers that are sensitive to some form of light (Shahrubudin, Lee, & Ramlan, 2019). In a study comparing the surface roughness of FDM, SLA, and MJ printers, Mou and Koc (2019) found that SLA offered the smoothest surface finish, with an RA of 0.34mm ± 0.01. In terms of dimensional accuracy, Mou and Koc (2019) found that SLA and FDM has similar results in width and height, which is the XY plane in their paper. Also, SLA suffered from the same thickness accuracy as FDM, presumably because of the build plate adhesion layers (Mou & Koc, 2019). While SLA printers often offer superior layer resolution and surface finish to FDM, Mou & Koc (2019) found that they suffer from deformities and waviness in thin features. Like SLA printers, material jetting printers use a photosensitive material that solidifies under UV light (Shahrubudin, Lee, & Ramlan, 2019). Droplets are precisely placed by a print head and then exposed to UV light, creating parts with very low surface roughness and very high dimensional accuracy (Shahrubudin, Lee, & Ramlan, 2019). Mou and Koc (2019) found that the surface roughness of these printers was better than FDM but poorer than SLA. Although MJ printers are more expensive than SLA and FDM, Mou and Koc (2019) did not find that this technology performed better in terms of dimensional accuracy. Which technology is best for tensile strength? Tensile strength is defined as, “the greatest longitudinal stress a substance can bear without tearing apart” (Merriam-Webster., n.d.). This is an important property of any prototype or production part that must bear some kind of a longitudinal load, such as a crane hook. This property, for example, is very important to the aerospace industry (Shahrubudin, Lee, & Ramlan, 2019). Tensile strength of a part printed with an FDM 3D printer will vary depending on how the process parameters are set and path generation strategies (Gajdoš, Slota, Spišák, Jachowicz, & Tor-Swiatek, 2016, p. 87). For instance, one study found that increasing the raster width by 16\% resulted in a 21\% increase in tensile strength (Gajdoš, Slota, Spišák, Jachowicz, & Tor-Swiatek, 2016). Tensile strength of FDM parts seems to be impacted by the voids within the part that are created by nature of the way path generation draws the paths of extruded material (Gajdoš, Slota, Spišák, Jachowicz, & Tor-Swiatek, 2016, p. 87). Adjusting the path generation parameters to minimize the number of voids results in greater density and surface area between the layers, increasing the overall tensile strength (Gajdoš, Slota, Spišák, Jachowicz, & Tor-Swiatek, 2016, p. 87). Selective laser sintering (SLS) is a technology that uses lasers to fuse powder together (Shahrubudin, Lee, & Ramlan, 2019). With this technology, “Higher energy density is needed to reach maximum elongation performance and elongation is more sensitive to build orientation” (Starr, Gornet, & Usher, 2011, p. 423). Additionally, Star, Gornet, & Usher (2011) found that the yield stress of the part is highly dependent upon the build orientation for SLS printers. For instance, the study shows that the test part exhibited the most strength when the bar was printed with the long axis of the test bar in the X direction and width of the test bar in the Y direction with a laser power of approximately 14W (Starr, Gornet, & Usher, 2011). Which technology is most cost-effective? There are many factors which go into calculating the cost of 3D printing. “How much does 3D printing cost” (2020) outlines various factors including print preparation costs, hourly printing costs, cost of the machine, cost of material, maintenance cost, training cost, and error cost. Print preparation costs involves the necessary process of calibrating the machine and materials to print the prototype correctly. Hourly printing costs cover the costs associated with how much time the machines run for. These costs include electricity costs, operator cost, and amortization cost. Cost of material will depend on what type of material a prototype needs to use. “3D Printer Material Cost” (2020) outlines several materials types for 3D printing with PLA ranked as the least expensive at $15-$20 per kg, and TPU as the most expensive at $87-$110 per kg. Maintenance costs is often overlooked but is necessary to factor into the cost of 3D printing. Printers have many moving parts which require cleaning and lubrication as well as occasional replacement. Error costs cover situations in which a prototype comes out incomplete due to a printer error like jams, misalignments, or running out of filament. These errors often result in restarting the print job and disposing of the damaged prototype. Lastly, training costs covers the cost associated with training the operators of 3D printers. All these factors combined result in a highly variable cost of 3D printing depending on the specific needs of the business (“How much does 3D printing cost”, 2020). What gives a material impact strength? Impact strength is how much energy from impact a material can take before breaking or fracturing, and the impact strength of a 3D printing material comes from a combination of the material used along with the construction of said material. Strong materials for impact strength are acrylonitrile butadiene styrene and thermoplastic polyurethane. (BCN3D,2020) These materials may not be the best fit for every project using 3D printing but will hold the most impact strength. A material can also be reinforced using fiberglass and in doing so will increase the impact strength. How can the current material be improved? Impact strength is the measure of how much impact a material can take while keeping its rigid shape. What gives a material impact strength is both what the material is made of as well as the path design the material has. As shown in figure 1, the same material can be strengthened if the path of the material changes. The parallel path is the typical structure of material, while the Bouligand structure forms a stronger impact strength. (Elsevier,2020) While the structure is a great way to raise the impact strength of the material, having a strong material to build off is important as well. According to the Journal of Composites Science, many traditional materials lack fiber. Through their testing they show that a fiberglass reinforcement to these materials gives the material a much higher impact strength. References 3D printer material cost in 2020 – overview. All3DP. (2021, July 30). https://all3dp.com/2/3d-printer-material-cost-the-real-cost-of-3d-printing-materials/ Benwood, C., Anstey, A., Andrzejewski, J., Misra, M., & Mohanty, A. K. (2018). Improving the impact strength and heat resistance of 3d Printed MODELS: Structure, property, and Processing Correlationships during fused deposition Modeling (FDM) of poly(lactic Acid). ACS Omega, 3(4), 4400–4411. https://doi.org/10.1021/acsomega.8b00129 Canton, A. the A. C. (2014, July 24). Raw materials used in 3d printing. think3D. https://www.think3d.in/raw-materials-for-3d-printing/. Cekic, A., Muhamedagic, K., Begic-Hajdarevic, D., & Djuzo, N. (2020). Effect of Process Parameters on Dimensional Accuracy and Tensile Strength of FDM Printed Parts. Annals of DAAAM & proceedings. Chan, H. K., Griffin, J., Lim, J. J., Zeng, F., & Chiu, A. S. (2018). The impact of 3D Printing Technology on the supply chain: Manufacturing and legal perspectives. International Journal of Production Economics, 205, 156-162. Dermeik, B., & Travitzky, N. (2020). Laminated Object Manufacturing of Ceramic‐Based Materials. Advanced Engineering Materials, 22(9), 2000256. Dietrich, C. A., Ender, A., Baumgartner, S., & Mehl, A. (2017). A validation study of reconstructed rapid prototyping models produced by two technologies. The Angle Orthodontist, 87(5), 782-787. Flynt, J. (2018, February 2). History of 3d Printing TIMELINE: Who invented 3d printing. 3D Insider. https://3dinsider.com/3d-printing-history/ Formlabs. (2021). Compare Formlabs SLA 3D Printers Tech Specs. https://formlabs.com/3d-printers/form-3/tech-specs/ Gajdoš, I., Slota, J., Spišák, E., Jachowicz, T., & Tor-Swiatek, A. (2016). Structure and tensile properties evaluation of samples produced by Fused Deposition Modeling. Open Engineering (Warsaw), 6(1), 86-89. Gurr, M., & Mülhaupt, R. (2016). Rapid prototyping. Rapid Prototyping - an overview | ScienceDirect Topics. https://www.sciencedirect.com/topics/materials-science/rapid-prototyping Hofmann, M., Williams, K., Kaplan, T., Valencia, S., Hann, G., Hudson, S. E., ... & Carrington, P. (2019, May). Occupational Therapy is Making Clinical Rapid Prototyping and Digital Fabrication. In Proceedings of the 2019 CHI Conference on Human Factors in Computing Systems (pp. 1-13). How much does 3d printing cost? 3d printing price calculator. Bitfab. (2020, September 22). https://bitfab.io/blog/3d-printing-cost/ Kabir, S. M., Mathur, K., & Seyam, A.-F. M. (2021). Maximizing the performance of 3d printed fiber-reinforced composites. Journal of Composites Science, 5(5), 136. https://doi.org/10.3390/jcs5050136 Liverani, E., Toschi, S., Ceschini, L., & Fortunato, A. (2017). Effect of selective laser melting (SLM) process parameters on microstructure and mechanical properties of 316L austenitic stainless steel. Journal of Materials Processing Technology, 249, 255-263. Mou, Y. A., & Koc, M. (2019). Dimensional capability of selected 3DP technologies. Rapid prototyping journal, 25(5), 915-924. Shahrubudin, N., Lee, T. C., & Ramlan, R. (2019). An Overview on 3D Printing Technology: Technological, Materials, and Applications. Procedia manufacturing, 35, 1286-1296. Schniederjans, D. G. (2017). Adoption of 3D-printing technologies in manufacturing: A survey analysis. International Journal of Production Economics, 183, 287-298. Starr, T. L., Gornet, T. J., & Usher, J. S. (2011). The effect of process conditions on mechanical properties of laser-sintered nylon. Rapid prototyping journal, 17(6), 418-423. Strongest 3d printing materials: Impact resistant filaments. BCN3D Technologies. (2021, July 23). https://www.bcn3d.com/strongest-3d-printing-materials-impact-fatigue-resistant-filaments/. Sun, Y., Tian, W., Zhang, T., Chen, P., & Li, M. (2020). Strength and toughness enhancement in 3d printing via bioinspired tool path. Materials & Design, 185, 108239. https://doi.org/10.1016/j.matdes.2019.108239 Merriam-Webster. (n.d.). Tensile strength. In Merriam-Webster.com dictionary. Retrieved August 9, 2021, from https://www.merriam-webster.com/dictionary/tensile\%20strength Wang, H., Soulé, R., Dang, H. T., Lee, K. S., Shrivastav, V., Foster, N., & Weatherspoon, H. (2017, April). P4fpga: A rapid prototyping framework for p4. In Proceedings of the Figure 1 Layer resolution of select 3D printing technologies. Note. This figure shows the layer resolution, or the resolution in the Z axis, of three different 3D printers representing three different technologies (Mou & Koc, 2019).