Instructions for Use IFU for ultra gloss and transparency

Most prints lose their gloss and transparency becoming hazy, translucent, and even whitish, when they are cleaned with isopropanol, ethanol or even with our milder Cleaning Fluid Bio after printing (we call them fresh prints since they are not fully cured).

The use of alcohols, such as ethanol and isopropanol, also reduce significantly the mechanical properties of most clear and colored prints, weakening and making them brittle: Comparison of different methods for cleaning and post processing 3D printed resins

Printing

Follow our Instructions for Use "IFU"  for different printing technologies and applications

Required equipment for cleaning 3D prints:

  • A low cost wash & cure machine of 100 Euro can be used, such as Wash & Cure machine or a similar one can be used for cleaning and light postcuring prints
  • A thermal oven (optional, needed if method 2 is used)

Cleaning and post processing Methods 1 & 2

The following cleaning and post processings methods are cost effective, fast and easy to use. They are ideal for obtaining maximum mechanical, gloss, and transparency of clear prints. Follow our post processing instructions without cutting corners for getting optimum results:

Method 1: Light box post curing of wet prints by immersion/dipping in Cleaning Fluids 

Method 1 tends to give less transparent finishings than Method 2, consequently if 100% transparent finishings are desired without polishing, then ignore Method 1 and follow Method 2 (explained in full detail below)

Features:

  • Method 1 is a fast & easy process which requires the use of Cleaning Fluid UNW1 Bio or Cleaning Fluid UNW2 Bio for cleaning and light post curing prints 
  • Cleaning Fluid UNW1 Bio has very good cleansing yield, very low viscosity and a balsamic fragance (not recommended for dental and biomedical applications since it leaves a residual balsamic taste unless is fully removed before use in the mouth)
  • Cleaning Fluid UNW2 Bio has medium viscosity, has a sweet taste and it is odorless
  • Both have MSDSs  free of hazards and risks
  • Choose Cleaning Fluid UNW1 Bio if maximum clarity is needed since tends to provide improved clarity with most 3D printed resins 
  • Choose Cleaning Fluid UNW2 Bio if increased biocompatibility is mandatory

Drawbacks:

Comparison of 3Dresyns Cleaning Fluids

Cleaning Fluid Main properties Clarity of prints Safety Application
UNW1 Bio Ultra Non Whitening Balsamic fragance cleaner with very low viscosity (<10 cps at 25ºC) and with very low  hydrophillicity and polarity for washing and cleansing prints without haziness High No risks Washing and light postcuring of durable prints by dipping at room temperature
UNW2 Bio Ultra Non Whitening Odorless cleaner of medium viscosity (<160 cps at 25ºC) with medium hydrophobicity and polarity for washing and cleansing prints without haziness High No risks Washing and light postcuring of durable prints by dipping at room temperature and for thermal postcuring up to 100ºC (or higher)
NW1 Bio Non Whitening Odorless cleaner of low viscosity (<50 mPas at 25ºC) with low hydophillicity and polarity for washing and cleansing prints (confers less clarity than UNW1 & UNW2 Bio) Medium No risks Washing and light postcuring of durable prints by dipping at room temperature and for for thermal postcuring up to 100ºC (or higher)
Bio Odorless biocompatible cleaner of low viscosity (<50 mPas at 25ºC) with high hydrophillicity and polarity for washing and cleansing prints (confers less clarity than UNW1 Bio, UNW2 Bio and NW1 Bio) Low No risks Washing and light postcuring of durable prints by dipping at room temperature

 

Method 1 process:

  • Remove prints from the build platform with a spatula
  • Cut the supports
    • Dip prints inside a washing basket in a washing container filled with Cleaning Fluid UNW1 Bio at room temperature or UNW2 Bio warmed at 50ºC for removing any uncured resin from the prints while stirring with a magnet stirrer (wash mode of the Wash & Cure machine). If needed use a brush to remove off any potential uncured resins attached to the prints 
    • Once prints and washed and cleaned dip them again in another transparent container filled with fresh and clean Cleaning Fluid UNW1 Bio or UNW2 Bio and postcure them at room temperature for 15-30-45-60 minutes (cure mode of the Wash & Cure machine):
      • light box curing times depend on the power and wavelength of your specific light box
      • low light power postcuring units require longer times than high power postcuring units
      • high light power postcuring units can cause yellowing and decrease of mechanical strength
      • too long light box postcuring can also cause yellowing and decrease of mechanical strength
    • After light box postcuring remove Cleaning Fluid UNW1 Bio or UNW2 Bio from the surface of the prints by spraying isopropanol on its surface to remove any rest of Cleaning Fluid UNW1 Bio or UNW2 Bio

    Options and different possible scenarios:

    • If the prints are too sticky without yellowing, increase the light postcuring time inside clean Cleaning Fluid UNW1 Bio or UNW2 Bio
    • If the prints are non-sticky with yellowing and embrittlement, decrease the light postcuring time inside clean Cleaning Fluid UNW1 Bio or UNW2 Bio until yellowing and embrittlement decrease
    • Once the prints are non-sticky and without yellowing nor embrittlement the optimum settings have been determined

    Method 2: Light box post curing of dry prints in air atmosphere

    Method 2 is the best method for ensuring than prints are 100% transparent since it does not require the use of any cleaning fluid which may reduce clarity of fresh prints. 

    Features:

    • Ideal for dripping out of the uncured resin from the fresh prints by gravity in an oven at <65ºC
    • Requires the use of a thermal oven for dripping out the uncured resin from the prints after printing

    Method 2 process:

    • After printing cut the supports and let the uncured resin drip out by gravity from the surface of the prints in the upside down position in an oven heated at <65ºC ( typically between 50-65ºC) from 15 to 60 minutes (leave prints upside down, and rotate them for maximum drip out by gravity)
      • the higher the viscosity of the resin the higher the recommended oven temperature for dripping out
      • low viscosity resins do not need oven temperatures >50ºC
      • high viscosity resins need oven temperatures >50ºC, between 50ºC and 65ºC
      • the higher the viscosity of the resin the longer time and the higher the temperature needed for dripping out
      • avoid temperatures above 65ºC to prevent yellowing
    • Postcure the dry prints (dry, non dipped in any cleaning fluid) in a normal light box for 15-30-45-60 minutes* at room temperature
    • Turn the prints upside down and postcure them for other 15-30-45-60 minutes* 
    • Clean and remove any residual stickiness by spraying ispropanol isopropanol IPA on the prints (use a spray bottle to ensure that clean IPA is always used)

    Options and different possible scenarios:

    • If the prints are too sticky without yellowing, increase the light postcuring time
    • If the prints are non-sticky with yellowing and embrittlement, decrease the light postcuring time until yellowing and embrittlement decrease
    • Once the prints are non-sticky and without yellowing, nor embrittlement, the optimum settings have been determined

    *Note: The optimum time for printing and post curing each 3D resin needs to be determined by experimentation since depends on many variables beyond our control, such as the specific printer, printing and light box specifications and settings, including variables such as the light power, wavelength, exposure times, total energy dosage, etc.

    • Printers and light boxes with too high light power with too long exposure time can cause some yellowing and decrease of mechanical strength "embrittlement" due to over curing
    • Pritners and light boxes with too low light power with too short exposure time can leave excessive uncured monomers and potentially cause risks and hazards in dental and biomedical applications due to under curing
    • For printing biocompatible resins for dental, orthodontic, implants, and other biomedical applications read: IFU for biocompatible resins

    Final cleansing process for Methods 1 & 2 when printing biocompatible devices

    For printing biocompatible devices these final cleansing steps are needed to cure any residual uncured monomers, and/or to remove any extractables, leachables, contaminants and byproducts:

      • Can be dipped (recommended) in Cleaning Fluid UNW2 Bio for thermal postcuring at high temperature between 70 and 100ºC for 20-30 minutes, or longer if needed, to cure any residual uncured monomers, and to remove both hydrophilic and hydrophobic extractables, leachables, contaminants, and byproducts
      • Have to be dipped in water (required) for thermal postcuring between 70 and 100ºC for 20-30 minutes, or longer if needed, to cure any residual uncured monomers, and to remove hydrophilic extractables, leachables, contaminants, and byproducts
      • For more information read our more detailed Instructions for Use IFU for biocompatible resins

      Summary

      • When instructions are followed without cutting corners prints with excellent gloss, transparency, surface quality, mechanical strength, and safety can be successfully made. The cleansing yield depends on the dipping time and temperature in Cleaning Fluid UNW2 Bio and water. The higher the temperature the shorter the time needed for fully cleansing the prints
      • Some 3D resins have been designed to withstand high temperatures (eg boiling water) without mechanical degradation nor yellowing. The higher the temperature the faster and the higher the cleansing yield resulting in increased polymer conversion and removal of extractables, leachables, contaminants, and byproducts
      • Some 3D resins can suffer a significant decrease of mechanical strength when exposed to high temperature. In these cases, use lower temperature (eg 60~70ºC) and longer cleaning time to prevent any potential decrease of mechanical strength
      • Biocompatible prints will not be ready for usage until maximum polymer conversion and full cleansing are achieved. Biocompatible prints should be free of extractables and leachables
      • The safety and biocompatibility of prints are responsibility of medical device manufacturers since their quality and safety depend on the design, implementation, quality assurance and "in house" production of their products with the right printing and post processing protocols and controls

      For more info read: Instructions for Use IFU for biocompatible resins

        How to reuse dirty Cleaning Fluid?

        Expose the Cleaning Fluid in the washing container to sunlight, or with or without stirring to light in the light box or curing machine. After several minutes the uncured resin will cure as small particles. Then, use a paint filter to separate and remove the cured resin from the recycled cleaning fluid, which can be used again and again for washing prints.