Printing Guidelines Somos® PerFORM HW

Somos® PerFORM HW

Last updated on 2 September 2021

Somos® PerFORM HW, the DLP version of industry-leading Somos® PerFORM, offers high dimensional stability and minimal warpage, ideal for 3D printing tooling. This resin is also ideal for applications that require steady performance in high pressure and harsh environments such as parts for wind tunnel testing.

The best flexible prototyping resin

Somos® PerFORM HW is a DLP version of industry-leading Somos® PerFORM stereolithography resin. It offers higher stiffness and higher temperature performance that is required for applications such as tools for injection molding. Somos® PerFORM HW is robust and offers high dimensional stability and low warpage. This resin is ideal for applications that require steady performance in high pressure and harsh environments off the printer and in use.

Download the product information here.

Technical Data

Printer Requirements

It is required to use a printer capable of a 5 mW irradiance output or higher.

Safety Instructions

Please adhere to the following guidelines:

  • Read and understand the Safety Data Sheet (SDS) before using the material.
  • Avoid contact with eyes, skin & clothing by wearing the following Personal Protective Equipment (PPE):
    • Safety Glasses/Goggles
    • Gloves
    • Laboratory Coat
  • Keep the work area clean.
  • Avoid spreading material on clean surfaces.
  • If material is found on clean areas, it should be cleaned off immediately with a disposable paper towel and isopropanol.
  • Wash hands regularly after handling material.
  • Provide adequate ventilation. Respirators or fume hoods should be considered if adequate ventilation is not available.
  • Prevent build-up of volatile substances from materials and solvents.
  • Remove dust from clean and finished parts.
  • See the Covestro Safe Handling Guide for UV materials for further safety instructions.

Preparing Equipment

Operating conditions

We recommend the following room conditions:

  • Ambient temperature of 20°C – 25°C (68°F – 77°F).
  • Humidity of less than 40%.
  • Minimize dust in resin chamber/build platform.
  • Use UV filters for lighting and external windows.

Replacing Material

When replacing material, remove and clean any resin contacting surfaces such as the machine tray, membrane etc. thoroughly, dispose of used material and cleaning products (solvents, paper towels, etc.) properly and follow vat installation procedures.

Machine Maintenance

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:

Light Engine

  • Keep light engine area dust free and clean. Periodic preventative maintenance, in accordance with manufacturer recommendations, will increase the life of the light engine and improve its quality.
  • Have the light engine serviced periodically per guidance of the equipment manufacturer. The typical frequency is two to three times annually.

Machine Computer

  • Inspect the cooling fans for electronic components regularly to ensure they are working properly.
  • Install back up hard drives to ensure you do not lose any data. This is very important, especially for older equipment.
  • Make sure the latest computer software service packs are installed are your system for optimal performance.

Mixing Guidelines

Composite material settles over time and so requires occasional mixing. To ensure proper consistency, adhere to the following guidelines:

  • Mix the re-fill material before every build using using a tongue depressor, spatula or similar device.
  • Mix the vat after every build that takes longer than 12 hour, if applicable.
  • To reduce settling it is recommended to keep re-fill material agitated on a bottle roller that is capable of ~18-25 rotations per minute.

Pre-Mixing

With any composite or filled material, it is helpful to mix the material prior to use. If a bottle roller is not available you can use a small “paddle” blade attached to a laboratory stirrer or hand drill. Mix the material in the bottle for 1 minute. Move the paddle around the inside of the bottle—including up and down on the inner edges—to make sure all the material has a homogenous consistency. 

Build Parameters

Build parameters are subject to site conditions and the printer being used. The parameters mentioned below can be considered base settings that you can tweak for improved styles. Please also consult the printer manufacturer print guidelines and settings.    

Machine Settings

Before beginning a new build, check the resin chamber for crashed parts and cured resin, ensuring the bottom of the platform or membrane is intact since the resin may have high adhesion forces. Confirm the machine is properly calibrated and has predictable energy delivery on all areas of the build platform.  It is required to use a printer capable of a 5 mW irradiance output or higher.   

Guidance for Build Parameters

The recommended Z-resolution range for all parts built is between 50 – 100 micrometer. The recommended exposure duration for first layer and burn-in regions is between 20 and 30 seconds with exposure delays of 10 - 20 seconds prior to starting the next layer

For model regions the recommended exposure duration is between 2 and 5 seconds with exposure delays of 3 - 5 seconds in between layers.  Note:  If necessary based on part geometry moving  toward the lower end of the exposure scale will increase feature accuracy.

For larger printed parts or those with complex geometries it may be necessary to reduce the separation speed to achieve successful prints.  Speeds as low as 0.5mm/s may be necessary.

Parts can be densely packed if the part design is short and/or rigid, with a Z-wait as low as 3 seconds per layer.

Longer parts printed in the Z direction or thin-walled parts can begin to swell slightly in the later stages of the build or after appreciable height of thin-walled parts are achieved, though this should not affect part quality. For these kinds of parts, increase part spacing to a minimum of 2 mm and increase the Z-wait to a minimum of 5 seconds per layer.

Printing at under 0.10 mm (100 microns) layer thicknesses may need increased Z-wait to compensate for lower modulus “green” parts and reduced gap for resin flow.

Printing at over 0.15 mm (150 microns) layer thicknesses may lead to increased separation forces between membrane and green part, though this should not affect overall print.

Postprocessing

Solvent Free Cleaning:  For simple geometries and testing parts solvent free cleaning provides a fast and efficient method of cleaning.

  • Simply use a dry lint free cloth/towel and wipe away any excess resin.  Repeat with clean cloth until no residual resin appears on the surfaces of the part. 
  • If necessary, use a low pressure air gun (ex. https://www.mcmaster.com/air-guns/blowguns-10/) to provide enough force to clean any residual resin from features but not damage the parts.
  • Repeat wiping with clean cloth until part is considered free from any residual resin.
  • Proceed with UV chamber cure and thermal post-cure steps as desired.
    • For UV Post Cure Apparatus (PCA), 30 minutes per side. Bulbs – TLK40W/05-HPUV and TLK40W-03 are recommended.
    • For other post cure chambers, follow recommended manufacturer instructions. It may also be necessary to experiment with times to achieve best results.
    • For Thermal Post Cure (TPC), place the parts in a room temperature oven that is allowed to ramp up gradually to the appropriate hold temperature (160°C) over a two hour period.  Maintain the hold temperature for two hours, and then allow to cool down gradually over a two hour period.

IPA Solvent Cleaning:  Provides a more intricate cleaning for parts with fine features and crevices that are not suitable for cleaning with the solvent free method. (Processing in IPA will result in a white chalky residue on sidewalls and feature surfaces of the part.)

  • As soon as the print concludes it is recommended to wait a minimum of 10 minutes before proceeding with any post-processing steps.
    • This includes exposure to any cleaning solvents, UV chambers for post-cure, and thermal ovens.
    • This is to allow part strength to be fully established prior to post-processing.
    • This step also allows excess resin to drain off of part(s).
    • Remove the build platform with parts attached from the printer.
    • Make sure to cover the parts if not working in a UV light shielding environment to prevent additional UV exposure.
  • Remove the parts from the build platform by applying gentle pressure with a flat scraper between the part and platform.
  • Clean the parts in IPA by dipping them in the solvent to expose all surfaces while cleaning with minimum pressure on all part surfaces using a soft-bristle type paint brush (or equivalent) until all residual resin has been removed.
    • The parts do not need to remain submerged in the solvent, but can be completely submerged during cleaning.  It is recommended not to exceed 5 minutes of continuous submersion during the cleaning and brushing steps.
  • Blow the parts dry using a low pressure air gun (ex. https://www.mcmaster.com/air-guns/blowguns-10/)  that has enough pressure to remove residual solvent but not damage any parts.
  • Once all surfaces are free from residual solvent allow to sit in a hood for ~30-60 minutes.
    • Note:  If using an alternate solvent other than IPA it may be necessary to allow a longer duration of drying in the hood for slower evaporating solvents. Initial recommendation would be to double the duration to 120 minutes or consult the Covestro team if there are any questions on this step.
  • Once the part has been completely dried proceed with placing in a UV chamber for ~30 minutes per side.
  • If thermal post-cure is desired proceed with this as the last step by placing the parts in a room temperature oven that is allowed to ramp up gradually to the appropriate hold temperature (160°C) over a two hour period.  Maintain the hold temperature for two hours, and then allow to cool down gradually over a two hour period.  Note:  To avoid thermal burns allow parts to cool completely before handling

Note:  Presently we are not seeing the use of a standard ultrasonic unit with IPA as removing any of the chalky white residue from the parts. The current recommendation is to perform the cleaning process using the method described above or the PostProcess Technologies cleaning method that immediately follows.  Please contact the Covestro team with any questions.

PostProcess Technologies Cleaning: The use of PostProcess Technologies proprietary cleaning detergent and equipment allows for deeper ultrasonic cleaning on parts while showing the ability to remove chalky white layers on sidewalls and feature surfaces.  (Note: The steps described below use a detergent that is considered hot. To avoid harm to the operator take care to utilize temperature resistant gloves and/or other utility devices to aid in lowering and lifting the basket slowly to avoid splash.)

  • Heat detergent (PLM-405) in PostProcess cleaning equipment to 50°C (Takes between 60 – 90 minutes to achieve depending on ambient temperature and system being used.)
  • Once desired temperature is achieved place drained parts previously removed from build platform in basket and lower slowly into detergent. 
  • Set automatic cycle to run at the following parameters:  temperature of 50°C, ultrasonic level of 4, duration of 1 hour.
  • Start automatic cycle.
  • After the 1 hour cycle finishes lift the basket and remove the part(s). 
  • Remove any resin debris by washing the part(s) with water and scrubbing using a soft-bristled brush.
  • Blow dry using a low air pressure air gun (examples: https://www.mcmaster.com/air-guns/blowguns-10/) to ensure all residual debris is removed.  Use low air pressure and take care not to damage parts.
  • Place part(s) back into basket, lower slowly into detergent, and start one additional 1 hour cycle with same settings as used previously.
  • Once second cycle finishes raise basket and remove parts. Rinse parts again in water and blow dry making sure the part is free of any additional debris and completely dry.
  • Leave part(s) to dry in air for an additional 60 minutes to make sure all residual detergent/water is completely removed.
  • Once dry, proceed with post-processing as described in the IPA cleaning method above. 

Disposal Instructions

In some areas, partially cured or uncured waste UV material may be classified as hazardous waste, and requires special packaging. Please always refer to the SDS for disposal information.

Transportation Disposal

Contact the governmental or other body that regulates waste disposal in your area to determine the disposal protocols.

Packaging-Transportation-Disposal Methods

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.

Solvent Disposal

Solvents should be isolated in a sealed, marked container and disposed of as “hazardous waste” in accordance with all applicable laws and regulations.

Clean-Up Material Disposal

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.

FAQ/Troubleshooting

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.

Issue: Delamination

Delamination occurs on the bottom layer of parts or on the corners in what is described as a “bite mark” type defect.

Solution: Reduce separation speed to as low as 0.5mm/s.

Issue: Roughness

Solution: Reduce exposure duration of model region.  Approaching 2 – 2.5 seconds will improve feature accuracy.

Issue: Parts not adhering to supports or support surfaces chipping upon removal

Solution: Support structures need to be more robust in the form of solid supports and not lattice type supports. Additionally, the amount of depth that the support has building into the part may need to be increased to achieve better adhesion to part surfaces. If supported surfaces are chipping, it is recommended to reduce support density around radiuses and heavily supported areas so that one support does not overlap into another.

How can we help?

Contact our experts to discuss how DSM can help you tap into the full potential of additive manufacturing.