Last updated on 13 October 2020
Somos® WaterShed Black provides a solution to build rigid, tough parts, while eliminating the need for painting. With similar properties and processing as Somos® WaterShed XC 11122, this multipurpose resin provides the same benefits in a black stereolithography material.
With Somos® WaterShed Black, there is a new stereolithography resin, black in color, on the market. With faster processing times and the elimination of the need for painting, Somos® WaterShed Black is a time and resource saver.
With its improved formulation, Somos® WaterShed Black has up to a 50% faster processing speed, offering minimal finishing and more consistent processing over time. WaterShed Black is a truer black color off the machine vs. others currently available. This material also has a smooth surface finish, as well as superior moisture and chemical resistance.
Download the technical data sheet here.
|Ec||11.5 mJ/cm2||[critical exposure]|
|Dp||6.50 mils||[slope of cure-depth vs. In (E) curve]|
Please adhere to the following guidelines:
We recommend the following room conditions:
When replacing material, make sure you clean the vat thoroughly, dispose of used material and cleaning products (solvents, paper towels, etc.) properly and follow vat installation procedures.
Before pouring resin into machine always shake bottle for 15-30 seconds to ensure that the color is well mixed. This should be done before each resin addition.
Vats of resin should be mixed weekly or as needed to ensure color is homogenous. This is especially important if the vat has been idle for more than 48 hours. Mixing can be performed using the “platform stir” scripts available on some SLA systems or using a drill with a mixing blade. If using a mixing blade mix vat for a minimum of ten minutes. If using the platform stir 15-30 minutes will be sufficient.
Contact your equipment supplier for up-to-date technical support for your equipment. Below are a few common checks that will help you build parts successfully:
Build parameters are subject to site conditions and machine efficiency. The parameters mentioned below can be considered base settings that you can tweak for improved styles.
Check to see that the Zephyr blade is clean of any residue by running a gloved finger along each side of the blade. If there is any residue, gently wipe it off with the proper tool.
Before beginning a new build, always check the Zephyr blade to ensure there were no changes after any build crash or other adverse events that may have changed the gap.
Also, check that the resin level in the blade is set to the halfway point. On builds with large flat or trapped volumes, check that the blade does not run out of material. If it does, material starvation could be causing it to give an incomplete part re-coating.
The build style of choice is Exact™ (Old Aces™). It offers the best:
To achieve an even thickness using a solid-state laser with Exact™, perform the following calculation: Smax = 0.4* DL * FL *1000
The minimum beam diameter (in X or Y directions) should be used when calculating the maximum scan speed.
To ensure that the Smax is properly calibrated, please refer to the following chart of common stereolithography machines.
The Smax should not exceed the recommended hatch speed for the machine being used.
During a build, you may find that excess material builds up on flat surfaces and in cavities. There are two ways to clean these:
After thoroughly air-drying the parts and checking that they are free from liquid resin residue, UV post-cure the parts for 20 minutes, rotating the part once after 10 minutes.
In some areas, partially cured or uncured waste UV material may be classified as hazardous waste, and requires special packaging.
Contact the governmental or other body that regulates waste disposal in your area to determine the disposal protocols.
Packaging-Transportation-Disposal methods must prevent any form of human contact with the waste UV material, even if it is classified as nonhazardous or unregulated. This therefore precludes the use of disposal methods that might result in groundwater or surface water contamination.
Solvents should be isolated in a sealed, marked container and disposed of as “hazardous waste” in accordance with all applicable laws and regulations.
Soiled clothing, empty containers, etc., should be disposed of in accordance with the applicable “hazardous waste” guidelines. If any of these items contain uncured or partially cured UV-curable materials, the disposal method used must prevent any form of human contact, including any that could result in groundwater or surface water contamination.
Below are some examples of common issues and troubleshooting solutions. Consult this part of the guide if you are having difficulties and do not hesitate to contact our Tech Support.
Delamination occurs on the bottom layer of parts at the corners or on part edges.
Solution: Check Blade
Have the physical gap on your re-coating blade checked.
Watch the buildup of the first few layers of the part to determine that the surface is being properly coated with material. Check for signs of material starvation or de-wetting.
The top surface of the part is not smooth and level.
Solution: Check Re-coating Blade
This condition is somewhat common and arises due to the viscosity of the material and the presence of debris that may become suspended in it.
Check the re-coating blade to make sure the bottom surface is clean and filter debris from the vat.
It is very important that you maintain the correct material viscosity in your stereolithography machine. The viscosity can increase over time, and this can cause problems in building parts. If the viscosity increase is severe enough, the material may have to be replaced, resulting in significant expense and lost production time.
If increasing viscosity is identified early, the material can, in most cases, be saved. Regularly measuring resin viscosity can provide an early indication of the problem. This must be done even if the machine is not used often, as resin viscosity can change even when the machine is idle.
Depending on the viscosity range of the material you want to test, use the appropriate-sized cup, based on Zahn Cups guidelines. You will also need a long-stem thermometer that mounts onto the Zahn cup handle and a stop watch.
Remember: Whenever you have material in your machine, measure and record its viscosity once a week.
|Seconds||Approximate Viscosity (CPS)|
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