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Metal 3D Printing Service

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CapabilitiesVapor Smoothing 3D Printed Parts

Vapor Smoothing 3D Printed Parts

Xometry’s vapor smoothing service provides low-cost finishing for additive-manufactured parts, resulting in a surface finish that rivals injection molding.

How It Works
Compatible Materials
Benefits
Design Tips
Applications
New!

Vapor Smoothing 3D Printed Parts

3D printing is one of the best ways to get low-volume production goods. However, plastic 3D printing tends to have one significant trade-off: parts with coarse surface finishes. Powder bed fusion processes like selective laser sintering (SLS) and HP Multi Jet Fusion (MJF) leave a matte, sugar cube-like surface finish. Fused deposition modeling (FDM) shows distinct layer lines. For the last 30 years, post-process surface finishing like abrasive media tumbling, hand finishing, or coatings have minorly improved the surface finishes of 3D printed parts. If cosmetics are a priority, engineers may choose other processes entirely like injection molding, machining, or urethane cast parts.


With the introduction of chemical vapor smoothing, a technology that smooths the surface of 3D prints and enhances mechanical performance via vaporized solvents, 3D printed plastics are now more suitable than ever for low-volume production. This process works on most 3D printed polymers and elastomers, including over twenty 3D printing materials available through Xometry. Read on to learn more about chemical vapor smoothing, its benefits, and its applications.

    vapor smoothed part

    What Is Chemical Vapor Smoothing?

    Xometry has adopted AMT’s PostPro3D chemical vapor smoothing technology. Unlike physical smoothing processes such as sanding or media tumbling, vapor smoothing does not remove material on the workpiece. Instead, a vapor finishing agent (FA 326) is introduced into a sealed processing chamber with the parts. Although the finishing agent is the same, different processing parameters are used for different materials and geometric features. Parts are racked, or hung, in a 600 x 400 x 400 mm chamber to maximize the surface exposure to the vapor. The vapor clings to the part surface where it creates a controlled chemical melt. This melt reduces the surface peaks and valleys by liquifying and redistributing material and evening the surface. The melt also has the effect of enhancing shine.

    Once the parts are finished, the chamber is heated to evacuate the finishing agent to a collection vat. No residue is left on the parts. Smoothed parts are then ready for shipping or another secondary process such as dyeing.

      AMT PostPro3D vapor smoothing machine

      What 3D Printed Materials Can Be Vapor Smoothed?

      Compatible Materials for Chemical Vapor Smoothing through Xometry
      Material NameProcessQuoting Process
      Material Name

      Nylon 12

      Process

      SLS, HP MJF

      Quoting Process

      Instant Quote

      Material Name

      Nylon 12, Glass Bead

      Process

      SLS, HP MJF

      Quoting Process

      Instant Quote

      Material Name

      Nylon 11

      Process

      HP MJF

      Quoting Process

      Instant Quote

      Material Name

      Thermoplastic Urethane, TPU 88A

      Process

      HP MJF

      Quoting Process

      Instant Quote

      Material Name

      Polypropylene (PP)

      Process

      HP MJF

      Quoting Process

      Requires Review

      Material Name

      Nylon 11 EX

      Process

      SLS

      Quoting Process

      Requires Review

      Material Name

      Nylon 12, Carbon-Filled (CF)

      Process

      SLS

      Quoting Process

      Requires Review

      Material Name

      Nylon 12, Aluminum-Filled (AF)

      Process

      SLS

      Quoting Process

      Requires Review

      Material Name

      Nylon 12, Mineral-Filled (HST)

      Process

      SLS

      Quoting Process

      Requires Review

      Material Name

      ABS-M30 (6 colors)

      Process

      FDM

      Quoting Process

      Requires Review

      Material Name

      ABS-ESD7

      Process

      FDM

      Quoting Process

      Requires Review

      Material Name

      ABS-M30i

      Process

      FDM

      Quoting Process

      Requires Review

      Material Name

      ABSi

      Process

      FDM

      Quoting Process

      Requires Review

      Material Name

      ASA (10 colors)

      Process

      FDM

      Quoting Process

      Requires Review

      Material Name

      Nylon 12

      Process

      FDM

      Quoting Process

      Requires Review

      Material Name

      Polycarbonate (PC)

      Process

      FDM

      Quoting Process

      Requires Review

      Material Name

      PC-ABS

      Process

      FDM

      Quoting Process

      Requires Review

      Material Name

      PC-ISO

      Process

      FDM

      Quoting Process

      Requires Review

      Material Name

      ULTEM 1010

      Process

      FDM

      Quoting Process

      Requires Review

      Material Name

      ULTEM 9085 (2 colors)

      Process

      FDM

      Quoting Process

      Requires Review

      The table above shows every Xometry material that can be produced with a vapor smoothing machine, including those which may require a manual review. You can get an instant quote on these materials by selecting "Vapor Smoothing" under the "Finishes" drop-down menu.

      How Much Does Vapor Smoothing Cost?

      You can get instant pricing and lead times on vapor smoothing in the Xometry Instant Quoting Engine℠ based on the process, material, quantity, and part geometry for the most popular HP MJF and SLS materials. Because the process is batch-based, costs are relatively low per part and will decrease with increased order volumes. Xometry typically adds between 1-5 business days to lead times for vapor smoothing. 


      Xometry will manually review vapor smoothing orders for fused deposition modeling and specialty materials like SLS high-performance blends, Nylon 11 EX, Nylon 12 AF, Nylon 12 HST, and Nylon 12 CF. Please select "Custom" as your finish option and submit the quote for an expert review.

        nine Xometry X's that are 3D printed

        The Benefits of Vapor Smoothed 3D Prints

        Vapor smoothed parts have improved cosmetics and are comparable to injection molding surface finishes. Standard SLS parts typically have a surface roughness greater than 250uin Ra, but with chemical vapor polishing can improve to below 125uin Ra and as low as 40uin Ra. In some studies, chemical vapor smoothing improved material surfaces by 800%-1000%. It is important to note that chemical vapor smoothing re-distributes surface material to provide a sealed, smooth surface but it does not create a polished surface. There will still be visible surface topology and minimal layer lines.


        Chemical vapor smoothing can significantly increase the viability of 3D prints in food processing, medical devices, and consumer products, and is recommended for end-use applications in these industries. Notably, vapor-smoothed nylon 12 3D prints effectively reduce bacterial attachment and growth compared to standard nylon 12 3D prints. Studies have shown that vapor-smoothed SLS and HP MJF parts conform to and pass multiple biocompatibility and safety tests.


        Other benefits of chemical vapor smoothing include:

        • A uniform, sealed surface, on 3D printed parts
        • Improved tensile, elongation, and flexural performance
        • No extra coatings; the surface is the part's material
        • Significantly reduced moisture absorption
        • Closed loop, repeatable processing results
        • Ability to polish non-line-of-sight features
        • Retains features and dimensional accuracy
        • No residual chemicals or media in features
        • Improved cosmetics and enhanced colors
        3D printed housing
        Slide 1 of 7
        Comparing a vapor smoothed and standard finish SLS nylon 12 part
        3d printed X's
        Xometry logo in nylon 12
        Vapor smoothing
        Vapor smoothed SLS versus unsmoothed SLS
        Chemical vapor smoothing HP MJF 3D prints
        Vapor smoothing TPU rubber 3D prints
        Comparing a vapor smoothed and standard finish SLS nylon 12 part
        3d printed X's
        Xometry logo in nylon 12
        Vapor smoothing
        Vapor smoothed SLS versus unsmoothed SLS
        Chemical vapor smoothing HP MJF 3D prints
        Vapor smoothing TPU rubber 3D prints
        Comparing a vapor smoothed and standard finish SLS nylon 12 part
        3d printed X's
        Xometry logo in nylon 12
        Vapor smoothing
        Vapor smoothed SLS versus unsmoothed SLS
        Chemical vapor smoothing HP MJF 3D prints
        Vapor smoothing TPU rubber 3D prints

        Surface roughness of chemical vapor smoothed SLS part (left) next to a standard finish part (right)

        Chemical Vapor Smoothing for Health and Safety Products

        Vapor Smoothing Passes Health and Safety Tests
        TestResultsDetailsNormative Reference
        Test

        Food Contact Test

        Results

        PASS

        Details

        SLS printed PA-12 parts chemically vapor smoothed with PostPro3D does not affect the consumer health nor influence the quality of food.

        Normative Reference

        According to regulation
        (EC) 10/2011 Annex V, Chapter 3, Table 3, OM 3, 2 hours at 70°C.
        DS/EN1186-01:2002
        DS/EN1186-03:2002
        DS/EN1186-14:2002

        Test

        Skin Irritation Test

        Results

        PASS

        Details

        SLS printed PA-12 parts chemically
        vapor smoothed with PostPro3D did
        not cause a skin-irritating effect.

        Normative Reference

        ISO 10993-10 (2013);
        ISO 10993-1 (2018);
        OECD TG 439

        Test

        Cytotoxicity Test

        Results

        PASS

        Details

        MJF printed PA-12 parts chemically
        vapor smoothed with PostPro3D did
        not cause a cytotoxic effect.

        Normative Reference

        ISO 10993-5 (2009);
        ISO 10993-1 (2010);
        ISO 10993-12 (2012)

        Test

        Microbiological Test on MRSA Bacteria

        Results

        PASS

        Details

        MJF printed PA-12 parts chemically vapor smoothed with PostPro3D show a reduction of bacterial growth quantified as 99.88% against MRSA

        Normative Reference

        MOD ISO 22196: 2011

        Test

        Microbiological Test on E. coli Bacteria

        Results

        PASS

        Details

        MJF printed PA- 12 parts chemically
        vapor smoothed with PostPro3D show a reduction of bacterial growth
        quantified as 99.78% against E. coli.

        Normative Reference

        MOD ISO 22196: 2011

        The chemical used for vapor polishing is safe and the closed-loop process of AMT’s PostPro3D system ensures that there is no extra residue left on the parts after smoothing. In fact, studies have shown that vapor-smoothed SLS and HP MJF parts conform to and pass multiple biocompatibility and safety tests concerning food contact, skin irritation, cytotoxicity, and bacterial growth. The results are summarized above and more details can be found in this AMT PostPro3D document on safety certifications.

        Design Tips for Vapor Smoothing 3D Prints

        • Add radii to sharp internal corners to prevent rounded voids
        • Keep wall and feature thicknesses above 0.040" (1 mm) to avoid distortion or defects
        • Keep wall thicknesses uniform, similar to injection molding
        • Be mindful that orientation-specific build lines may still be present, but smoothed
        • Racking marks may be visible depending on how the work was held during processing
        • Flexible materials, like TPU 88A, may have more surface imperfections versus rigid materials
        HP MJF Vapor Smooth 3D Printing
        Vapor smoothing

        On-demand Webinar: Everything You Need to Know about Vapor Smoothing 3D Prints

        Join industry experts for a webinar on making smooth, cost-effective, mechanically enhanced 3D prints with our vapor smoothing finish.
        Read the Full Case Study
        Understanding and preventing vapor smoothing defects

        Understanding and Preventing Vapor Smoothing Defects

        8 tips to prevent vapor smoothing defects in your parts
        Read the Full Case Study

        Applications for Vapor Smoothing

        Concept models

        Concept Models

        Enhanced cosmetics, better coloration, and sealed surfaces can make vapor smoothed 3D prints showstoppers.

        Fast parts and fast shipping

        Rapid Prototyping

        Vapor smoothing does not significantly increase lead times, allowing for highly functional parts in record times.

        Digital manufacturing

        Direct Digital Manufacturing

        3D printing vapor smoothing is a bulk finishing process, making it an ideal way to build large quantities of customized parts.

        Commercial and industrial 3D printing services

        Get Started on Your 3D Printing Quote

        Free shipping on all 3D printing

        Why Choose Xometry for 3D Printing Services?

        Massive Network Capacity

        Endless Options

        Choose from millions of possible combinations of materials, finishes, tolerances, markings, and certifications for your order.

        Instant Quoting Engine

        Easy to Use

        Get your parts delivered right to your door without the hassle of sourcing, project management, logistics, or shipping.

        Guaranteed Quality

        Guaranteed Quality

        We are ISO 9001:2015, ISO 13485, and AS9100D certified. Only the top shops that apply to become Suppliers make it through our qualification process.