{"id":15,"date":"2016-07-29T11:54:56","date_gmt":"2016-07-29T19:54:56","guid":{"rendered":"http:\/\/davenet.mine.nu\/?page_id=15"},"modified":"2016-07-29T11:54:56","modified_gmt":"2016-07-29T19:54:56","slug":"make-it-or-break-it-now-in-color-the-effects-of-colorants-on-the-strength-of-3d-printed-pla-polymer-objects","status":"publish","type":"page","link":"http:\/\/davenet.mine.nu\/?page_id=15","title":{"rendered":"Make It or Break It, Now in Color: The effects of colorants on the strength of 3d-printed PLA polymer objects"},"content":{"rendered":"

Make It or Break It
\nNow in Color:<\/b><\/span><\/span><\/p>\n

The effects of colorants on the strength of 3d-printed PLA polymer objects<\/b><\/i><\/span><\/span><\/p>\n

<\/div>\n

Acknowledgments<\/b><\/span><\/span><\/p>\n

Dr. Dan Fernandez, professor of Physics and Environmental Science at California State University of the Monterey Bay, for the initial idea of studying 3d printed objects, materials, and fill patterns.<\/span><\/span><\/p>\n

My father for the use of the Solidoodle 2 Pro, printing the test objects, for helping build the testing instruments, and for his assistance in conducting the experiments.<\/span><\/span><\/p>\n

My mother for help with proofing and editing.<\/span><\/span><\/p>\n

Fitness Evolution Health Club, Monterey, for allowing me to conduct my compression tests on their equipment.<\/span><\/span><\/p>\n

Dr. Paul Strivers for steering me to read about polymers.<\/span><\/span><\/p>\n

Mr. James Arao for providing tips on an engineer’s perspective of this study.<\/span><\/span><\/p>\n

BFS Landscape Architects for the use of their plotter in creating my presentation board.<\/span><\/span><\/p>\n

Abstract<\/b><\/span><\/span><\/p>\n

Motivated by findings in a previous science project about the strength of different 3D printer filaments, this study explores the effect of colorant on the strength of polylactic acid (PLA), a biodegradable filament made from sugar cane, corn or yuca root. In the earlier research, it was found that objects printed with PLA and with the honeycomb fill pattern demonstrated greater durability in stress tests. In the process of researching, it was noticed that objects printed with yellow PLA filament broke more easily than those printed with natural color filament, which gave the impression that printed objects of different colors may react differently in strength tests. For that reason, the earlier study tested white printed objects only. What would happen if objects of different colors were put through strength tests?<\/span><\/span><\/p>\n

<\/p>\n

Introduction<\/b><\/span><\/span><\/p>\n

3D printing remains a growing technology for home and business use. The use of color in the manufactured prints adds variety and allows consumers to be more creative with their print ideas. Color is added to filament prior to extrusion. The granulated PLA <\/span><\/span>(C<\/span><\/span>3<\/span><\/span><\/sub>H<\/span><\/span>4<\/span><\/span><\/sub>O<\/span><\/span>2<\/span><\/span><\/sub>)<\/span><\/span>n <\/span><\/span><\/sub>resin is blended with an organic pigment, then melted and pushed through a single screw extruder (Smith, 2015). Organic pigments such as azine dyes are widely used today in the making of 3D printer filament.There is not a lot of information available to users to explain why a filament of one color would be weaker than a filament of another color. Frequent checking on Makerbot and Soliforums (3D printing companies with online forums for problem-solving) brought no answers on the subject. Considering that pigment is regarded as an additive and an additive can make a difference in the mechanical properties of plastic, it may be worthwhile to study the behaviors of different color filaments under stress to note differences. Consumers may be interested to know which color filaments are stronger than others. <\/span><\/span><\/p>\n

Although there are no clear explanations available as to why colored filaments may have different strengths, there have been studies of the behavior of plastics in general with colorant and a study that specifically tested the behavior of colored PLA (Evans 2014). As the trend toward organic dyes took over in the last decades, a study done by Kanu et al (2001) looked at the differences between the organic and inorganic pigments. They tested plastics colored with inorganic and organic pigments to determine differences in strength tests. They wanted to understand the effects additives like colorant had on the strength and durability of plastics. Along with the discovery that there was little difference in the behavior of plastic colored with either organic or inorganic colorants, they also found an increase in mechanical properties of plastics colored with organic pigments. In response to the move from inorganic to organic dyes, Christie (2010) asserted that organic pigments could create a tear point in materials and limit performance in some applications such as tensile tests. \u201dCertain combinations of pigments and dyes can result in a phenomenon called phototendering, in which products lose strength and flexibility from exposure to sunlight\u201d (Christie, 2010 p. 3). Evans (2014) tested colored PLA printed from RepRap printers which are comparable to commercial printers. She also suggested that color was a variable among others that affected the mechanical properties of 3D printed plastic. Testing the elastic modulus in tensile tests with different color beams, she found the natural color beam to be the most rigid, while black performed better in strength tests. She commented that the \u201ctuning\u201d of the printer might have been a variable. <\/span><\/span><\/p>\n

What effect does colorant have on the structure of objects printed with PLA in the Solidoodle2 Pro? For this study, I asked Dominic at Solidoodle Support which colors were the most popular among consumers buying 3D printer filament. Using a Solidodle2 Pro, a 3D printer, PLA filament was tested in the popular colors using a similar method of strength testing as used in a previous research where the strengths of PLA and ABS were compared, with the focus now being the effect that colorant has on the behavior of the filament under different stresses. <\/span><\/span><\/p>\n

PLA was chosen because in the previous research project, it outperformed ABS in strength tests. The honeycomb pattern was used because it proved the most durable compared to other fill patterns. The colors tested were blue, white, black, yellow, and natural. The strength of the colored plastic were tested with the following forces:<\/span><\/span><\/p>\n

Flexure<\/span><\/span>– measuring the flexibility of the object
\n<\/span><\/span>Shear<\/span><\/span>– finding the breaking point of the object
\n<\/span><\/span>Torque\/torsion<\/span><\/span>– measuring the behavior of the object when twisted
\n<\/span><\/span>Tension<\/span><\/span>– observing what happens when the object is pulled in opposite directions
\n<\/span><\/span>Compression<\/span><\/span>– examining how plastic test objects behave under a lot of pressure<\/span><\/span><\/p>\n

Question:<\/b><\/span><\/span> Does color affect filament strength? What effect does colorant have on the structure of plastic? Of colors used for PLA <\/span><\/span>(C<\/span><\/span>3<\/span><\/span><\/sub>H<\/span><\/span>4<\/span><\/span><\/sub>O<\/span><\/span>2<\/span><\/span><\/sub>)<\/span><\/span>n <\/span><\/span><\/sub>3D printer filament which color is strongest?<\/span><\/span><\/p>\n

Hypothesis:<\/b><\/span><\/span> Filament with no dye or added color (natural) will out perform the plastics with color in stress tests. Of the colored filaments, yellow will be the weakest and white will be the strongest.<\/span><\/span><\/p>\n

Independent Variable:<\/b><\/span><\/span> <\/b>The color<\/span><\/span>s<\/span><\/span> of the plastic objects<\/span><\/span><\/p>\n

Dependent Variable:<\/b><\/span><\/span> <\/b>The force needed to break the object<\/span><\/span>s<\/span><\/span><\/p>\n

Controlled variable: <\/b><\/span><\/span>The colors, shapes, <\/span><\/span>densities<\/span><\/span> of the objects <\/span><\/span>and all the filaments used for printing are PLA-based.<\/span><\/span><\/p>\n

Materials<\/b><\/span><\/span><\/p>\n