The stereolithographic details have a high aesthetic impact, they have a very smooth surface that adapts to special surface finishes such as painting, metallization or screen printing.
Stereolithography produces three-dimensional models of high visual impact using resins that resemble plastic materials such as ABS, clear polycarbonate or polypropylene.
It is a rapid prototyping technology that implements the principle of additive manufacturing using the heat generated by a laser to solidify the photosensitive resin only where it is needed to realize the object.
The modelling starts at the base of the object and move upwards by 0.1mm-thick layers until the object is fully formed. Once complete, the parts are subjected to UV treatment in a dedicated furnace to stabilize the resin and give it characteristics similar to the final material.
Stereolithography produces three-dimensional models of high visual impact using resins that resemble plastic materials such as ABS, clear polycarbonate or polypropylene. It is a rapid prototyping technology that implements the principle of additive manufacturing using the heat generated by a laser to solidify the photosensitive resin only where it is needed to realize the object. The modelling starts at the base of the object and move upwards by 0.1mm-thick layers until the object is fully formed. Once complete, the parts are subjected to UV treatment in a dedicated furnace to stabilize the resin and give it characteristics similar to the final material. Additive manufacturing technologies produce almost no waste material. Liquid resin still in the tank of the machine and unaffected by the solidification process can be reused. Therefore the only waste elements are eventual supports, i.e. light mesh structures which the software automatically elaborates to guarantee the stability of parts of the object during the production process and which are easily manually removed by the operator. The material is extremely workable signs of the supports and layering are eliminated in order to obtain a smooth surface suitable for a great variety of finishes, including paint, metallization or screen-printing. For this very reason, we can refer to objects realized by stereolithography as high visual impact prototypes. We can therefore create models very similar to final injection moulded pieces to be used at trade fairs, in the preparation of catalogues and their images or in sales force promotional materials. Here some of the technical details, with our stereolithography machines, we can produce monolithic prototypes of up to 750x650x550mm to an accuracy of ± 0.05mm via ENVISIONTEC technology or pieces that can resist temperatures of up to 140°C with the material HTM140.
How does stereolithography work?
Stereolithography was the first ever method developed for rapid prototyping. It is based on the photo-polymerization of liquid resins sensitive to ultraviolet radiation emitted by a laser source with a system of mirrors. The interaction of the laser light with the photo-polymer triggers a chemical reaction that solidifies the latter. The prototype is thus built up in layers. To reduce execution time, the laser completely polymerizes only the outside contours of surfaces and connects them with a honeycomb structure. Subsequently, the piece is fully exposed to UV rays by means of special lamps for time enough to complete the polymerization.
What degree of precision do your machines have?
Our machines have precisions ranging from ±0.05mm to ±0.15mm.
What materials can be used?
Accura Xtreme Plastic Transparent Accura Clearvue HTM140 D7
In what format should I send the files?
You can send files in various formats: -.stl, -.stp, -.iges, -.x_t, -.model, -.sat, -.prt, -.par or native SolidWorks, Catia V5 (r15) or Cimatron -.step. In some cases, for CNC machining, for example, a 2D drawing may be enough, though this can only be confirmed by our technical department on quotation. Once the order has been made, for all machining operations the 3D files will be used. The 2D files will only be used to check dimensional tolerances. In case of any discrepancy between the 2D and 3D files, Coesum will use the 3D files in its possession.
Can the prototypes be painted?
Yes, prototypes produced by stereolithography can easily be painted and subjected to surface treatments such as chromium plating, gilding and other plating treatments.
How big can monolithic stereolithography prototypes be made?
The maximum size depends on the particular machine and resin that you choose to use. The IPro8000 can produce monolithic prototypes up to 750 x 650 x 550 mm with Accura Xtreme Plastic resin. The SLA3500 can produce monolithic prototypes up to 350 x 350 x 250 mm with Accura ClearVue or Accura 25 resins. Finally, the ENVISIONTEC machine can produce monolithic prototypes up to 160 x 100 x 230mm with HTM140 or D7 resins
Can I make objects of any shape and thickness?
Yes, there are no limits to this technology in terms of shape, but it is recommended to follow good constructive practice in keeping internal and external walls thicker than 0.6 mm.
What purpose are stereolithography prototypes suited to?
This technology is ideal for objects with fine visual details and those that require particularly high dimensional and surface precision.
Can objects subsequently be machined for threads or holes?
It is preferable to account for threads and holes already in the 3D design in order to avoid any unnecessary damage. It is possible to insert metal insert during the process to facilitate assembly with other components.
What are lead times like?
The time it takes to produce an object varies from project to project but will be communicated on quotation by our commercial technicians.