Guide

Guides

Our guides are designed to give an idea of the possibilities offered by the technical solutions and the materials that we are able to supply.

Guides are currently are available about the different types of materials and styles of finishes, both for prototypes and pre-series production.

Nicola Felice Mon, 05/30/2016 - 11:48

Guida ai materiali

Guide to materials

Clicking on the images you can see a comparison of the characteristics of our more frequently used materials.

To see the characteristics of a specific material you can download the PDF in the datasheets section of the site.

Materials for prototypes

Materials for prototypes

Legend:

  Veri good / Recommended
  Average
  Not suitable / Not recommended

Materials for pre-series molds

Comparative table for pre-series materials
Nicola Felice Mon, 05/30/2016 - 12:22

Finiture per stereolitografia

Stereolithography finishes

Prototypes made in stereolithography can be finished in various ways, from basic finishing to RAL varnishing. Usually, the finishing is done only on the aesthetic side, unless otherwise agreed and with the exception of the transparent effect that requires finishing on both sides.

FB - Basic finishing

Finitura basic

This type of finishing is the basic finish directly derived from the machine, without further processing, except those strictly necessary to separate the object from the support platform. Surface quality depends heavily on machine positioning that can highlight or hide process stratification.

FS - Standard finishing

Finitura standard

This is the most common finish, consisting in sanding and sandblasting the piece, which thus assumes a translucent white appearance.

FT - Transparent finishing

Finitura trasparente

With the Watershed 1122XC material, it is possible to obtain a transparent glass-like finish. This is possible by sanding, polishing and painting the workpiece on both sides, compatibly with the geometry of the part.

FM - Metal finishing

Finitura metallizzata

In this case, the prototype, after being polished, is subjected to vacuum metallization. The final surface is glossy and has a highly reflective power, but may have slight cracking, which may also occur over time, due to the different dilatations that characterize the resin and the metal.

FP - Painted finishing

Finitura colorata

This type of finish is obtained by painting the model with a color you choose, glossy or opaque (RAL or Pantone shades are possible). In this way you can also get opaque metal-like finishes.

Martina Felice Fri, 10/27/2017 - 16:01

Finiture per pre-serie

Finiture per pre-serie

With silicone molds you can get a good variety of finishes, as explained below. All described effects (except metallic ones) can be applied on a pigmented support or on a transparent base (colorless or colored). Unless otherwise agreed, the finish is only made on the aesthetic side. Exceptions are transparent pieces, which are nevertheless finished on both sides.

FLL - Glossy smooth finish

Finitura lucida

This type of finish is obtained by polishing as much as possible the master prototype. The pieces thus obtained have a glossy finish and, if the material is transparent, the effect is similar to glass. Caution: this finish is hard to get and very time consuming; moreover, defects and scratches are very noticeable on the parts thus finished.

FLO - Smooth matt finish

Finitura opaca

This finish, characterized by a smooth but non-glossy surface, is one of the most used and versatile finishes, easily available on almost all geometries. If the casting material is transparent, the effect is that of mildly acidified glass.

FGL - Slightly rough finish

Finitura goffrata leggera

The FGL surface has a light roughness on it, which can have aesthetic purpose, but can also help hiding any irregularities that may occur in most complex prototypes. Also this is a very used and versatile finish.  On transparent material, the effect is similar to sandblasted glass.

FGG - Very rough finish

Finitura goffrata grossa

In this finish the texture is more evident. In some cases, high surface roughness can make defect correction difficult and can also reduce the mold life.

 

FST - Structured Finish

Finitura strutturata

A very special finish, characterized by a high roughness, which simulates a fibrous material. It greatly reduces die life.

 

FML - Polished metallic finish

Finitura metallizzata lucida

This type of finishing is achieved by vacuum-vaporizing metal. The coating is a few microns and therefore has aesthetic and non-structural purposes. The vacuum metallization procedure increases production times.

FMS - Finitura metallizzata satinata

Finitura metallizzata satinata

This type of finish is obtained by painting the parts with a matte metallic paint. Execution time and cost are lower than for vacuum metallization, but with this method you can not get the glossy effect.

Martina Felice Thu, 11/02/2017 - 15:05

Modelli trasparenti

Transparent models

3D printing and small series of transparent models

This guide is intended to help you understand how transparent models can be obtained from 3D printing and vacuum casting and, starting from the definition of the concept of transparency, provides indications on the possibilities and limits of these two solutions.

Prototipi trasparenti

What is transparency?

When we say "transparent" we are all pretty sure of what we mean, but there are aspects of the concept of transparency that are worth investigating, to better understand what you can expect when you want to get a transparent prototype from 3D printing.
Transparency is the capability of a body to allow the passage of light and therefore the vision of objects located beyond it.
This capability is determined by two factors:

  1. by the material of which the object is made, i.e. by its index of refraction: for example, having conventionally set the index of refraction of the vacuum to 1, the air is indexed 1.00029, the water 1.33, the glass about 1.5, the diamond 2.4;
  2. by the surface of the object: if the surface is rough, the actual incidence angle of light is not what you see macroscopically but varies from point to point because the various light rays hit the microscopic facets of the roughness, each characterized by a normal, with an overall effect of reflection and diffusion or alteration of the path of the light rays, which reduces the actual transparency.
Tabella degli indici di rifrazione di alcuni materiali

As a consequence, to obtain a transparent prototype it is necessary:

  1. to use a material with a good index of refraction, i.e. what we would call a transparent material;
  2. to have a surface as shiny as possible and free of macroscopic or microscopic geometric discontinuities.

How to get transparent models?

In the field of prototypes, the two ways to obtain this kind of result are stereolithography and vacuum casting.

In the case of stereolithography, it is necessary to use a transparent material such as Somos Watershed 11122XC and then proceed to finish the surface of the product until it is smooth and shiny. In most cases the object is then painted with transparent varnish to enhance the final effect.

The second path that can be followed to obtain a transparent model is to cast a transparent polyurethane inside a silicone mold. In this case, to ensure the transparency of the casted object, it is necessary that the master used to fabricate the mold, usually made by stereolithography, is perfectly polished and reflective, i.e. with the surface characteristics, and related problems, described in the previous paragraph.

Confronto tra prototipazione rapida e repliche siliconiche

Generally, it is worth following the first road when you want to make a single prototype and you want to contain costs, it makes sense to follow the second way if you want to make a small series of models and you are looking for more performing materials (in terms of mechanical strength and aesthetic quality).

Technical transparency or aesthetic transparency?

In both solutions described above, the methods required to polish the models involve a cost and, more importantly, they are not always possible. In general, in order to polish and paint an object, it is necessary that all its surfaces, internal and external, are accessible to finishing tools (usually manual tools) and to the paint that normally is airbrushed. If this is not possible, the transparency of the object will be somewhat reduced. This problem, however, is in many cases less restrictive than it may appear. To better understand the situation we should refer to the distinction that is made, in practice, between aesthetic transparency and technical transparency.

Confronto tra trasparenza tecnica e trasparenza estetica

The aesthetic transparency is the "glass type appearance" that we can expect for example from a lamp or from a refrigerator showcase: a transparency that allows us not only to see through without any attenuation or deformation, but also to appreciate the smooth and glossy finish of the surface.
The technical transparency is instead what we can ask for a pipe fitting, where we want to see the liquid flow, or for a box that is designed to contain electronic parts: in this cases, it is important to see through the surface, but its aesthetic appearance is much less important because the defects are not relevant or are easily confused with the other elements that make up the assembly. In this case, even if you can not polish and paint all surfaces perfectly, often the final transparency effect is quite acceptable also because it is important to keep in mind that any geometric discontinuity (edges, ribs, holes, turrets, etc.) determines a reduction in transparency.
In conclusion, when you want to create a transparent prototype it is important to decide what the real needs are because the so-called "technical transparency", in not only easier and faster to obtain, but also less expensive.


For an easy consultation on other media, this guide is also available in PDF format:

Would you like to know more?
If you have any doubts about whether to choose the stereolithography solution instead of silicone molds, or you want to better understand if you need aesthetic or technical transparency, do not hesitate to contact us!

Martina Felice Mon, 09/03/2018 - 10:53