Rapid Prototype Zone

Stereolithography or SLA is one of the most commonly used rapid prototyping and rapid manufacturing technology for creating several parts with excellent surface finish and high accuracy. Stereolithography is a mechanism used to perform Stereolithography Apparatus. SLA creates plastic parts or even objects a layer by marking out a laser beam on the surface of the liquid photopolymer. This category of substances initially developed for packaging and printing industry, solidifies quickly wherever the laser beam hits. As one layer is being entirely marked out it lowers a small distance into the vat of the liquid photopolymer and a subsequent layer is marked out exactly on the top of the first layer.

The self cementing property of this particular substance causes the layers to merge with one another and finally form an absolute 3D object after lots of similar objects are created. Some of these objects have undercuts or overhangs that must be actually maintained during the procedure of fabrication by maintaining the structures. These structures are automatically or manually designed and later fabricated along with the objects. When the fabrication procedure is completed these objects are elevated from the vat of the liquid photopolymer and then the supports are removed.

Stereolithography or SLA is being considered to provide one of the best surface finishes and exact accuracy of any technology of rapid prototyping. SLA is frequently regarded as the pioneer of the rapid prototyping business with the initial profit-making system was introduced in the year 1988. This particular system consists of a vat of photo-curable liquid photopolymer, a controlling system and an Ultra Violet Laser Beam. A podium is being lowered into the vat of the liquid photopolymer via the elevator system in such a way that the surface of the podium is the layer-width below the surface of the vat.

This laser beam then marks out the border lines and seals in the 2 dimensional cross segment of the model, hardening the resin anywhere it touches. As the layer is completed the podium sends down layer thickness where the resin flows over the first layer and then another layer is being created. This procedure continues until the entire model is completed. Once the entire model is completed the podium increases the vat and the extra resin is being drained. This completed model is later removed from the podium, washed clearly and then placed in an Ultra Violet oven for ultimate curving.

For so many years, a wide range of substances with properties intimating those engineering thermoplastics have been created. Restricted selectivity color altering substances for biomedical and additional applications are also available along with ceramic substances which are at present developed in large number. This particular technology is even remarkable for the big object sizes which are possible.

On the other side, working with liquid substances can be untidy and some parts quite often need a post-curing function in a completely separate Ultra Violet oven or an apparatus for absolute stability and treatment. In recent times, the latest technology of inject has even been extended to operate with photopolymers which result in systems which have both perfect accuracy and quick operation.

Stereolithography (SLA) is one of the easiest and quickest ways to prototype a physical model of your part to verify form, fit, and function as well as design verification and rib and fillet features. An SLA prototype can save time and money by avoiding costly mistakes before going to production as well as getting customer approval. Your tooling engineers can use the rapid prototype model to decide on the parting line, ejector pins, and gate locations.


Stereolithography was the beginning of the rapid prototyping industry and is still the most widely used. An SLA machine will build a part layer by layer, each layer being .002" to .006" thick, by using a solid-state laser beam to solidify the surface in a vat of liquid photopolymer, or SL resin.

The easiest 3D CAD file format Metro Rapid Prototyping can utilize is surface files (.STL) or any native ProE part file. IGS files can also be manipulated as well.

SLA models can be produced at Metro RP in a matter of hours or days, depending on the part size. The advantage using SLA prototypes over permanent hard tooling is the factor of time and cost. Prototype aluminum injection molds can take several weeks to produce and are several times the cost and lead time.

Some of the cleanest and most accurate prototypes come from SLA models using 3D CAD files. SLS machines are very quick and require little cleaning of the part off the machine, but the surface finish lacks the smoothness and detail as an SLA model. Typically, these parts are cheaper but require 2-3 times the amount of time to build.

Rapid Prototyping