Hi-Res 3D :: Technical Library

Process Description and Overview - A brief description of the SLA machine, materials and how parts are fabricated.

Materials - Data sheets for Duraform PA & Duraform GF (Glass Filled)

Why HiQ machines build better parts and are easier to run than older SLS machines (2000, 2500, Vanguard)

SLS Process Description and Overview

The Selective Laser Sintering (SLS) process, in fact any of the RP processes, begins by exporting your 3D CAD design from your CAD package in STL format. The STL file was originally created to work with the STereoLithography process and now the STL format has become the standard for all RP processes. All major CAD/CAM packages from Solidworks to Pro/Engineer include the ablity to directly export to an SLT file. The STL file contains your CAD design and the surface is made up of triangles. The smaller the triangles and the "cord height" the finer the detail on the surface of the part. There is an indirect relationship between # of triangles and files size in Mbytes. The greater the tesellation (# of triangles) the larger the file in Mbytes. We can help you export the appropriate file so that you get the best part.

The 3D design is then "sliced" in software and then built, layer by layer (or slice by slice) in the SLS machine. The laser that traces each layer is more powerful than the SLA laser and melts a Nylon based powder as it forms each successive layer. Each layer is melted to the layer below to create a homogeneous plastic part. This is why the SLS process produces the strongest protoype available.

As menioned above, the material used to built the part is a nylon powder. There is also a glass filled nylon available. Data sheets for each powder are located below.

After the entire part is built, the part is removed from the machine and is bead blasted to remove any loose powder. At this point the part is ready for shipment or for any secondary process that may be needed.

Materials

There are a wide variety of materials that can be run in SLS machines, from Nylon based plastics, to flexible rubber like materials, to metals. At present we are running the two most common materials. If you woudl like a quote on another SLS material, simply ask.

Below you will find links to datasheets for Duraform PA and Duraform GF. Duraform GF is the same base material as Duraform PA with glass bead added to the powder.

These 2 materials produce the strongest parts in the prototype industry. I have references that have done head to head comparison's for strength among the leading RP technologies and the SLS process won hands down. This is mainly due to the fact that the parts are fully dense and homogeneous when completed for excellent mechanical properties.

Duraform PA and Duraform GF Data Sheet - The industry standards. PA is more fleixibly with higher impact strength. GF is more rigid with lower impact strength. Both produce the toughest parts of any RP process.

Duraform EX Data Sheet - A newer material with much higher impact strength and elongation to break. This mateiral can be twisted like a pretzel before breaking.

Duraform FLEX Data Sheet - Rubber like mateial with a Shore A hardness of ~ 65. Can be infiltrated in several different colors.

You can get real time quotes for PA and GF. Please call or email for quote on the other materials.

HiQ SLS machines build better parts than older SLS machines (2000, 2500, 2500+ and Vangaurd) for the following reasons:

There are several reasons why newer SLS machines produce better parts than older SLS machines. First of all, the hardware is newer. Secondly the software that runs the machine is a recent version with better functionality and algorithms.

The HiQ machine has 2 main features that make it easier to run. This leads to more predictable results and better part quality. (more consistant accuracy, more consistent mechanical attributes and better surface finish)

The first feature is Sinterscan software. In older SLS machines the laser only moves parallel to one axis while sintering the part. In a HiQ machines with Sinterscan, the beam moves both parallel to the x axis and also parallel to the y axis. It alternates every other layer. The software also uses a function called part outline to aid in surface quality. See the part images below.

The second feature the HiQ utlizes is Intelligent Thermal Control. In SLS machines one of the more difficult things to do is to control the temperature of the surface of the material where the melting is taking place. On older SLS machines temperatures are set and adjusted constantly utlizing infrared sensors and operator know how. In the HiQ machine this process has been automated by utlizing intelligent real time feedback. The end result is that parts are more unifrom and predictable from machine to machine and build to build.