At Graphite Additive Manufacturing, our parts are offered with a variety of finishing options. Between our primary and secondary options, we have over 50 different combinations of finishing to provide you with the most suitable finish for your application. Primary finishing is the initial step that is done before parts leave the workshop – this gives components the required surface finish. Secondary finishing can then be done to provide additional functionality or change the cosmetic appearance of a part. This article will briefly explain the options, how they are most effectively applied and show what each one looks like.
Parts can be finished in one of seven different processes: Basic, Cosmetic, Sanded, Sanded-Deluxe, Light Sand & Blast, Clear-Polished and Clear-Lacquered. Each one is suited to a different application so knowing which finish is right for you is important when asking for a quote or placing an order.
If you are not sure which of our finishes is best for smoothing, sanding down, sealing and polishing 3D printed parts, then this will be a useful article to make sure you get the finish you desire.
Each of our technologies; Stereolithography (SLA), Selective Laser Sintering (SLS), Multijet Fusion (MJF) Selective Laser Melting (SLM) and Fused Deposition Modelling (FDM), have a standard finish which we think would suit most of our customers for the majority of applications. For SLA, SLM and FDM that finish is Basic and for SLS and MJF that finish is Cosmetic.
Basic finish, as the name suggests, is the lowest level of finish we offer at Graphite. In this process, the parts are cleaned and any support material is removed. It is important to note that build layer lines will still be visible. It is advised that only materials printed using the SLA, SLM or FDM technologies choose this finish. Typical applications include functional resin and metal parts and dissolvable mandrel technology.
The next level up from Basic is Cosmetic and is used for different applications depending on which technology you are using. For SLS, Cosmetic is the standard finish as it doubles up as the secondary cleaning process, removing all the excess powder around the parts left from the manufacturing process. The part also becomes shinier as a result, like the lead of a pencil. Typical applications include component housings, ducting, scale models and hand-held devices.
Cosmetic finish for SLA offers a smoother finish than Basic but not as smooth as a Sanded finish. It removes all the build layer lines and offers superior aesthetics when compared to Basic. It can be used to give Watershed a frosted glass effect.
Sanded and Sanded-Exterior
For those who require a smoother finish than the standard, we offer sanding of our parts. This is available for all technologies but in some cases, it may not be suitable for all materials. In this process, our skilled technicians sand the parts by hand, progressing through the grits to get a fine finish. Sanded-Exterior finish, a derivative of the Sanded finish, is a process where we only sand up to 50% of the available surface area and is applicable when the customer only wants certain areas smoothed. Typical applications for sanded finish include manifolds and dashboard components where a smooth, matt finish may be desired. For Sanded-Exterior, typical applications include visible component casings – where only one side will be seen, or the A-surface of composite tool where the other sides are not used to mould the composite.
Sanded-Deluxe and Sanded-Exterior-Deluxe
For customers who require the very highest level of surface finish and appearance of SLS parts. This finish takes the sanded finish to the next level with additional finishing to get the best surface finish possible. This finish produces the most uniform surface and is halfway between the lighter finish of Cosmetic and the muted tones of Sanded. Orientation plays a large role in the success of Sanded-Deluxe as the surface is so fine that lines start to appear and the Carbon content in the material reflects light in the orientation that they were built. This can often be mitigated by our skilled programmers orientating the part optimally. This finish is only applicable for SLS and MJF where typical applications include engine trumpets and premium automotive interior parts.
This finish is only applicable for the SLA material Watershed to produce a more transparent finish. Whilst not quite glass-like, the lacquer does help to increase the amount of light that can pass through the part by masking imperfections in the surface of the un-lacquered part. This finish is, therefore, a step up from Watershed Basic but still below our finial primary finish, Clear-Polished. Typical applications include prototypes, headlamp covers and liquid level indicators.
Clear-Polished takes Watershed SLA to the next level with near glass-like transparency, comparable to injection moulded surfaces. This manual process takes a lot of elbow grease to achieve but the results are worth the costs for certain applications. Like Clear-Lacquered, this finish is only applicable for the SLA material Watershed. Typical applications include glass or injection moulded transparent plastic prototypes and dials with complex geometries.
Light Sand & Blast
We now also offer a light sand & blast finish. This finish is our newest service for customers looking to remove the layer lines from SLA parts. An innovative process, produced out of the necessity for a simple yet effectively smooth finish. Typical applications include fluid conduits. This finish is only applicable for SLA.
For more information on our finishing options, or to request a free sample, please get in touch.