Colored Strong & Flexible Isn't Really Colored?

Discussion in 'Technologies and Hardware' started by eNonsense, Aug 30, 2012.

  1. eNonsense
    eNonsense New Member
    I'm new to getting things printed at Shapeways and until today only had 2 test prints in WSF and Alumide which I was really impressed with. Today I received a 2nd order of some actual designed items and was very disappointed with one of the parts I received in Black Strong & Flexible. It's a part with numerous 1mm deep hex shaped pits, many of which I noticed were still mostly or partially filled with powder. I took a small soft brush to clear out some of what I thought was unsintered powder, only to discover that it was actually WSF underneath and the color is just an external coating. This is no where on the material description pages. Is this the same story with all of the non-white strong & flexible materials? Here is the 3d file, and what I received.

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  2. stannum
    stannum Well-Known Member
    They are dyed, so if there was trapped powder and you cleaned it, the base white will show up. If you cut the parts, you will also see the white core.
     
  3. eNonsense
    eNonsense New Member
    Ok, that's fine. But the powder was hardly trapped. It took 10 seconds with an old toothbrush to clean it off and it was obvious that it was there. You could have held it upside down and tapped the back and a bunch would have fallen out. It's strange that they'd put it in the dye in that condition.

    I'll drop an email to customer support.
     
    Last edited: Aug 30, 2012
  4. mkroeker
    mkroeker Well-Known Member
    If the non-white "strong and flexible" materials are actually just normal WSF dipped in paint
    after a quick brushing, I think that this should be stated clearly on the materials page. (This
    seems to make them a poorer solution than just washing and (spray-) painting a model after
    delivery.)
    The current text creates the impression that the process uses appropriately colored starting
    materials ("nylon plastic that comes in a variety of colors" and even different maximum
    dimensions on the design guide page, just as if these were done on a different machine).

    To me, shapeways has had a much more professional appeal than the other low-cost competitors.
    (Said as a long-time lurker who just had his first few parts printed). Please keep up your technical
    standards (material documentation, terms&conditions WRT pricing scheme, print reproducibility)
    before you even consider adding facebook "like buttons" complete with their js tracking code and
    other short-lived "community experience" fads.

    Martin
     
  5. stop4stuff
    stop4stuff Well-Known Member
    Coloured S&F is actually dyed using acid dyes (the exact same dyes that can be used for dyeing clothes)
    WSF also takes diluted artists acrylic paint rather well, which also has the advantage of sealing the surface.

    @eNonsense Shapeways should be able to do a re-print for you, just send in images and ask :)

    Paul

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  6. mkroeker
    mkroeker Well-Known Member
    Thanks for the clarification. Still this should be somewhere on the materials page.
    (Or add a paragraph to the design tips page, somethink like "The black, red and
    purple finishes are produced by dyeing the white material after printing with an
    acidic dye akin to those used for dyeing clothes. See our tutorial at http://... for
    tips on how to paint WSF models yourself.")
     
  7. eNonsense
    eNonsense New Member
    I also agree that this info should be on the materials page.

    I'm more concerned about the quality control however. For a place that allows you to host your own store, it could sure impact the experience your customers have when buying your designs and reflect negatively on you, rather than just on shapeways. It makes you not want to offer your designs in these colored materials, which is really disappointing. Especially considering that again, this could have been prevented by actually looking at the part to notice that it isn't clean and hitting it with a toothbrush for 10 seconds before dyeing.

    BTW,
    I assume that the Black Fine Detail plastic is also dyed after production, because it's slightly splotchy and is softer than the white (which I know happens in some dyeing processes). I'm happy with these parts though. No complaints, as this splotchiness is apparent and expected by looking at the examples on the materials page.
     
    Last edited: Aug 31, 2012
  8. stop4stuff
    stop4stuff Well-Known Member
    AFAIK, Black detail is black all the way through. The spotchiness as seen on the material page is probably uncured polymer that can be removed by soaking in a warm weak solution of NaOH (Sodium Hydroxide/Lye/Casutic Soda) followed by rinsing under running water.

    Paul

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  9. eNonsense
    eNonsense New Member
    Noted.

    Thanks for the clarification.