3D Print Post-Processing

Basics

• This Page Aims to Lay Out The Existing Methods of Post-Processing 3D Printed Things
• It also will organize methods that need further investigation

Existing Methods

FDM Prints

Hand Sanding

• Pretty straightforward
• Needle Files , Deburring Tools , and Sandpaper rest is self explanatory
  • Also maybe a Microfiber Cloth / "bath" in the sink or a Parts Washing Bin to clean off any Microplastics / burnt bits
• A Hot Air Gun / SMD Electronics Rework Station can be used for small details like Stringing related "fuzz" ~~or just a Butane Lighter if you are desperate~~
• Main Downside is Time Spent

Tumble Finishing

• A Rotary Tumbler or Vibratory Tumbler can be used for some parts
• Given how much of a "rough process" this is, it cannot be used for more delicate prints
• It is a High Volume Batch Process though, so that can have it's advantages in time savings

Media Blasting

• Also known as "Sandblasting"
• Media Blasting is the more broad concept, and especially given the hardness of (most) FDM 3D Printed Plastics, a less "aggressive" media is most likely required
• Would need to look into the existing literature on all this
• In theory could something like Plastic Pellets / Plastic Regrind be used?

Solvent Vapor Smoothing

• This only works for certain plastics, but a Solvent (Typically Water or Acetone ) is vaporized in a chamber, the print is placed in there, and the vapor (partially) dissolves the surface of the material
• After a certain time period of exposure, the part (or the solvent if done in some fancy Solvent Recovery method, Vacuum + Bakeout ?) is removed
  • The solvent then evaporates leaving behind a smoothed (but sometimes deformed, reducing/predicting and accounting for this is key) surface
• (akin to Recrystalization / Zone Melting removing impurities, it does the same but for surface finish impurities)
• Main Downside is Solvent Cost (especially if Solvent Recovery (short of "don't dump the bucket down the drain until all of it was used/evaporated") isn't done) and the potential for part deformation)

FDM 3D Print Annealing

• Given they are Thermoplastics , FDM 3D Prints Can Be Either Re-melted, or Simply Heated Up
• This allows layer lines to "blur" and the part fuse into a single stronger one, or it can simply work in a manner similar to Post-Weld Heat Treatment
• In order to prevent part deformation/drooping etc this is typically done in some sort of media
• CNC Kitchen et al have documented using Plaster and Table Salt (Check if Iodonized Salt or just straight up Sodium Chloride (Although Did it also contain Anticaking Agents ...) )
• It needs to be studied, but if something along the lines of Chopped Glass Fiber / Chopped Carbon Fiber were used (or to an extent maybe just Carbon Black ), could something akin to Case Hardening be achieved?

Filler / Painting / Powder Coating etc

• This does not fix the core issues of Layer Lines etc, but can achieve the desired Surface Finish / aesthetics
• Certain processes, especially as shown by SLS 3D Printing may benefit from the more rough and/or porous surface finish (Perhaps a Synergy Between Dissolvable Annealing Media and this then)

Internal Links

• ASMBL (A Process that Solves The Problem of 3D Print Post-Processing in a Manner Similar To How Machine Finishing of Castings Addresses Metal Casting Defects . It is done "by layer" (or potentially every 5 layers etc to minimize the amount of toolchanges and thus save time) however to be able to still produce the Novel Designs allowed by 3D Printing
• Chemical Dipping vs Vapor Smoothing
  • That BigRep Article Mentions the Former, but i haven't heard of it until then, and i wonder how the reaction rate is different (is the "melting" far more drastic?)

External Links

• An Article by the Website "BigRep" Titled "GUIDE TO POST-PROCESSING 3D PRINTED PARTS: 16 METHODS"
• An Article by "All3DP" Titled "3D Printing Post-Processing: PLA, PETG, ABS & More"
  • This approaches it from a more Hobbyist Single Run Manufacturing / Low-Scale Manufacturing / Mid-Scale Manufacturing perspective