The Effects Of Color On Material Properties Of 3D Printed Components

The strength of object printed on filament-based 3D printers varies by the plastic used, the G-code used by the printer, the percent infill, and even the temperature the plastic was extruded at. Everything, it seems, has an effect on the strength of 3D printed parts, but does the color of filament have an effect on the stress and strain a plastic part it can withstand? [Joshua M. Pearce] set out to answer that question in one of his most recent papers.

The methods section of the paper is about what you would expect for someone investigating the strength of parts printed on a RepRap. A Lulzbot TAZ 4 was used, along with natural, white, black, silver, and blue 3mm PLA filament. All parts were printed at 190°C with a 60°C heated bed.

The printed parts demonstrated yet again that a RepRap can produce parts that are at least equal in material strength to those produced by a proprietary 3D printer. But what about a difference in the strength among different colors? While there wasn’t a significant variation in the Young’s modulus of parts printed in different colors, there was a significant variation of the crystallization of differently colored printed parts, with white PLA producing the largest percent crystallinity, followed by blue, grey, black, and finally natural PLA. This crystallinity of a printed part can affect the tensile properties of a printed part, but [Pearce] found the extrusion temperature also has a large effect on the percentage of crystallinity.

16 thoughts on “The Effects Of Color On Material Properties Of 3D Printed Components

      1. Black is one of the least consistent PLA you can get.

        Chinese suppliers have been known to throw all of their scrap color pellets into the mix. This is why some black is completely opaque, while others are slightly transparent. PLA by nature, unlike ABS, is naturally transparent, so any solid color will have more chemicals and dyes in it. For white it’s required, but it isn’t for black.

        Typically the more opaque, the higher the temp necessary.

    1. They usually do. Seems a bit pointless to me testing with fixed parameters, the correct way to do it is to test for maximum performance in the physical properties you need for each roll tested. That is what everyone who has a 3d printer does (or should do if it is important).

    2. That is more likely than not, and depends on your definition of ‘extrudes optimally’. The author compared different types of filament, and for one type, investigated a small range of temperatures. More temperature points would have cost more time and money. But perhaps you should rtfa instead of spouting of ‘what-if’s.

      1. If he’s extruding at one temperature only then he’s only looking at one data point shared commonly among a variable. The problem with that is different colors will affect the temperature required to achieve the results found from using only one data point: temperature. It would be a fair comparisson if you wanted to find the best filament to print at on a machine that worked optimally at one specific temperature, but 3D printers have a wide gamut of configuration. Therefore, by excluding the temperature variable and printing at a static setting across the board, the tensile strength of the plastic is undoubtedly going to be a false positive.

        1. > If he’s extruding at one temperature only […]

          Judging by the abstract (the actual PDF is behind a paywall), they aren’t — and that’s the very point jelle was making upthread.

          The authors are testing a range of printers (two), a range of pigmented filaments (five) *and* a range of temperatures. If they’re doing their job correctly (and lacking details to the contrary I’ll assume they are), it should be possible to find an “optimum” for each pair of (device, pigment) in there (if you know what kind of optimum you’re looking for).

  1. Theres definetly a difference in performance between different coloured ABS filaments.
    This is just from my personal experience.
    Black seems to be the most consistent and easiest to use so i always use that for critical parts. But i find i have to tune the settings for each and every batch let alone for different colours.

  2. If plastic is anything like metal, the rate at which it cools also affects crystallinity. Slower cool = larger crystals.

    A quick Googling suggests that for plastic, large crystals improve strength. So slow cooling is beneficial.

    Color affects cooling rate. Black heatsinks cool fastest, white cools slowest, and the results are in agreement with this. Although that’s a relatively minor factor, and perhaps overridden by the chemical effects of pigments on crystal formation.

    Changing extrusion temperature will change cooling rate, but other things too. Anyone experimented with alternate methods of slowing cooling rate? Heated build chambers? Streams of hot air directed at the plastic near the extruder?

    1. This sounds like what’s needed is a fang running hot, rather than cool air. that sounds like one would need slower print speed rather than the goal of faster deposition with cold air from a typical fang. Heated part means more chance of warping too. Damn shame the .pdf is off limits! Is anyone doing ‘open’ research?

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