Polymer finishing options

Our team of skilled finishers and modelmakers use a variety of in-house techniques to produce aesthetically pleasing and functional parts that are often comparable to the final manufactured item, with minimal time added to the delivery.

Whilst the layer based construction techniques of plastic 3D printing offer significant benefits in terms of build speed, it can sometimes give a stepped surface finish. From a purely functional aspect this is seldom a problem, however from the aesthetic perspective they may require additional finishing.

We ensure every last detail is taken care of and our bespoke finishing services offer a range of options from simply adding a colour or highlighting certain areas, to fully finished marketing models, or the inclusion of mechanical components, inserts or screw threads.

The resulting finished model or prototype part can play a vital role in functionality testing, securing tender bids, design verification and marketing photography.

Plastic additive manufacturing is a layer based process, which means that parts have a certain amount of stepping and surface roughness when they come out of the machine (rather like that of an Extra Strong mint). This may be perfectly acceptable to some customers; however, others want their parts to have a smoother, more refined finish, or require them to be coloured, painted, vacuum metallised, plated or resin impregnated.

One of the primary tasks required before any finishing work can proceed is to ‘dress’ the part to remove surface roughness, or the layering effect. Traditionally done by hand, this ‘rubbing down’ can be extremely labour and cost intensive.

The gentle action of our vibro finishing machine removes the labour to obtain smooth parts with minimal time and cost being added. A two hour cycle is sufficient for large batches of small to medium sized parts. The finished parts can be used in functional testing, assembly trials, product demonstrations and launches, or in marketing photography. Alternatively, the parts can be despatched directly to the customer without any further work, which is of particular benefit for applications such as fluid flow work.

Unlike more aggressive tumbling machines, this process can finish some of the internal features of components, such as holes and voids. The only limitations to the process are that the largest size part that can fit into the machine is approx. 300mm x 300mm x 300mm. Features and walls below 2mm thickness are unlikely to survive this process. 

We have pioneered a low cost method of improving the visual impact of our plastic 3D printed components with a revolutionary colouring process. Requiring no surface dressing, functionality and lead time remain unaffected. This post process is usually covered by a flat charge irrespective of parts count.

With plastic components finding themselves in a vast range of applications, they can be transformed by the application of a single colour. Assemblies become clearer giving a far better communication of design intent, and resilience to handling discolouration is enhanced.

Single parts or large batches can be supplied in a range of standard colours, including red, blue, green, orange, purple, yellow and, most popular, black. Additional colours may be available, with the ability, on occasion, to colour match to a specific pantone.

From a one-off rapid prototype model, to high volume production parts, our state-of-the-art paint shop enables us to produce stunning finishes for an infinite variety of end uses. 

Our highly skilled painters have over 60 years of combined experience in their field and all share a combined passion for perfection and pushing the envelope, by developing new finishing techniques in-house. 

We offer a wide range of paint finishes, from a simple colour change to a fully gloss topcoat as well as everything in between, all completed in a RAL or Pantone colour of your choice. 

The painting process is a manual one and as so will need to be discussed with one of our team members. Please get in touch with [email protected] and we will be delighted to assist you. 

Having worked closely with some of our industry partners over the last few years, we have developed a ‘metallised’ plating process (also known as metal deposition) for our Nylon and Glass Filled Nylon parts. This greatly enhances their functionality and strength, allowing them to be used in environments and within industry sectors that non-plated parts would struggle to compete in, enabling additive manufacturing to be used in more crucial applications than previously envisaged.

The mechanical properties of our Nylon and Glass Filled Nylon part have significant benefits of their own and are widely recognised as the materials of choice when a higher degree of performance is required. However, the plating process adds a higher level of stiffness and rigidity, as well as conductivity, electrical compliance in terms of EM or RF shielding and a considerably higher heat deflection temperature.

The plating process commences with a layer of copper being deposited and encasing the surface of the Nylon or Glass Filled Nylon component. A variety of metals can then be deposited onto the copper layer, including various finishes of nickel and chrome, or precious metals such as gold and silver.

Total layer thicknesses can be as much as 1000 microns, but the standard is usually approx. 100 microns. For instance, an average RF shield or EM coating is generally approx. 80 microns of copper and 20 microns of nickel. At approx. 150 micron surface layering, performance in terms of tensile strength increases by about nine times that of the standard Nylon material.

Due to the layer based nature of the additive manufacturing process, the surface texture of the plating will always replicate the surface finish of the original substrate. Although this layered effect can be reduced prior to plating using various in-house techniques such as vibro finishing, the plating process can’t deliver a mirror finish.

Plating is a time based process which can take a few days to reach the required thickness. Although there are methods available to produce constant layer thickness, it should be considered that with some component geometries such as deep holes or undercuts, the depth of the plating will vary considerably.

We can fit inserts into polymer AM parts, giving a robust thread for prototyping or manufacturing applications. We use a wide range of Tappex inserts.

Most of our inserts are fitted by heat staking them into the receiving hole. Minimum wall thicknesses should be exceeded where possible to strengthen the insert fitment. Other size inserts and types are available on request.

Please visit the Tappex insert guide here for best practices on designing the receiving hole.

The inclusion of text on a polymer part means that logos, branding, instructional messages, unique identification codes or batch numbers can be incorporated into the CAD design and generated during the build process. Text can be embossed or engraved.

General design guidelines are as follows:

Font: For best results we recommend using Arial font. Other fonts can be used. We advise you speak to our CAD experts for advice on whether they would build well on your part.

Size: Font size depends on the orientation of the build. A good minimum size recommendation is 14 point. Anything less than 8-10 point could become difficult to read.

As a general guide, 1pt = approx. 0.25mm. Therefore :-

14 pt = 3.6mm
18 pt = 4.6mm
20 pt = 5.0mm
24 pt = 6.1mm

Depth: Embossed or engraved at 0.5mm is achievable with 1mm giving excellent results. Other sizes can be achieved; however, this is dependent on part geometry and build orientation.

Orientation: Build orientation is best in vertical side walls; however, this is dependent on part geometry and any other critical features in the design. Talk to our CAD experts for advice on how to achieve the best results.