FAQ - LMF “Laser Metal Fusion” technology. Professional 3D printers with selective metal powder bed fusion laser.

During the printing process, is the material completely melted? Is any porosity present inside or on the surface?


The metal components printed with LMF (Laser Metal Fusion) technology generally have a rough surface but very high (close to 100%) densities, as the material is completely melted, not sintered.




What comes after the printing process?


The products manufactured with metal LMF technologies may be subjected to thermal treatment to relax any residual tension resulting from the process itself and to increase the mechanical properties (according to the material, various types of curing are possible, which may affect hardness, traction resistance and ductility).

The need to reduce surface roughness or satisfy very tight dimensional tolerance requires the use of different finishing technologies and surface re-finishing on the manufactured products. According to the material used, various kinds of machining technology (turning, milling), electrical discharge machining, polishing or electropolishing and surface coatings (PVD) may be used.




Can highly air-reactive materials be printed? What are the possible risks?


All materials are reactive to specific reagents, in various ways. That's why the process inside the work chamber occurs always in the presence of an inert gas and the oxygen concentration is very low (under .3%).

In the event of highly reactive materials like aluminum and titanium alloys, the machines are fitted with oxygen level sensors that enable it to be reduced to under 100 parts per million (100ppm).

The risks related to the management of reactive materials are eliminated during the work process. To eliminate all hazards during equipment setups, the machines identified with the RM (reactive materials) mark have an opening with gloves that allow powder handling always in inert atmosphere, avoiding all contact between materials and the external environment.




Can precious and/or reflecting metals be printed? How can I minimize the use of these materials?


Precious metals are particularly reflective at typical infrared laser wavelengths of 1047 nm. Some MYSYNT100 machine setups, identified with the PM (precious metal) marking, use a laser spot with a reduced 30 µm diameter to increase the energy density at the same laser power.

These machines are also distinguished by a kit of interchangeable cylinders to change the work field from Ø100 mm to 63.5 mm and 34 mm




Can I use new alloys or standard alloys from other suppliers?


The process parameters can be changed in all MYSINT series equipment, thus allowing the use of powders from suppliers other than Sisma as well. Additionally, the open parameters facilitate R&D activities aimed at characterizing new materials and applications.




How important are cleanness and maintenance inside the work chamber?


Room chamber cleanness during the manufacturing process is important to ensure quality and repeatability.

A laminar protective gas flow parallel to the countertop enables the removal of oxides and fumes resulting from the process. Gas is extracted, filtered and reintroduced in the work chamber.

The flow is designed to minimize recirculation within the chamber that may contaminate the protective glass and affect the success of the process.




How long will it take me to change material in the machine?


The change of material in machines with a cylinder system is very fast; a trained operator can perform a full change of material on MYSINT100 in less than one hour and on MYSINT300 in about 2-3 hours.




Can powder be reused? What tools will I need?


In the MYSINT100, unmelted powder can be removed around the piece to take the component directly in the machine, moving all the powder to be sifted to the recovery cylinder and using external laboratory equipment to sift the powders.

EVEMET 200 allows the removal of powder not melted during the process in the work chamber. The gloves on the work chamber door allow operators to work in inert atmosphere and the optional extractor fan ensures the complete removal in inert atmosphere of the powder inside the chamber.

MYSINT300 comes with a complete range of peripheral devices that allow any unsolidified powder around the piece to be removed, extracted and sifted in automatic or semiautomatic external work stations, eliminating all contact between operators and powder.




What are the maximum dimensions of the printable piece?


The working area of MYSINT100 machines in the standard, RM, DUAL and DUAL RM measures Ø100x1000 mm.

The maximum working area of MYSINT100 PM, PMRM and RM PRO versions measures Ø100x80 mm.

EVEMET 200 allows the machining of items measuring up to Ø200 x 200 mm height.

The working area of MYSINT300 measures Ø300x400 mm. The double load cylinder allows the use of the entire construction volume without stopping during the process to load new powder.




What's the size of the smallest printable item?


The smallest printable item depends on a combination of machine and material:

  • MYSINT100 with 30 µm beam spot (PM, PMRM) allows the manufacturing of pieces sized under 0.1mm
  • MYSINT100 and EVEMET200 with 55 µm beam spot allow the manufacturing of items as small as 0.15 mm
  • MYSINT300 features a 100 to 500 µm variable beam spot, with a minimal item size of approximately 0.2/0.25 mm





FAQ - DLP “Digital Light Processing” technology. Professional 3D printers using resin polymerization by means of light projection.

What are the differences between DLP and Laser SLA?


DLP (Digital Light Processing) stereolithography print technology is based on a digital light source (projector), emitting in the UV spectrum, able to polymerize layers of photosensitive polymeric resin. Unlike DLP, SLA laser technology is based on a UV laser source that irradiates photosensitive resin. The use of a DLP projector allows the polymerization of every layer in a single instant, which cannot be done with laser, as the latter has to trace an outline on the entire layer to be polymerized. This means that laser printing takes much longer, and they tend to increase as spot laser decreases, thereby creating a compromise between speed and productivity; this compromise does not exist for DLP technologies, as printing speed is not affected by resolution.




Which resins can be used with EVERES?


EVERES printers use proprietary SISMA EVERES resins only. Other third party materials do not qualify and are not compatible with the machine.




How does print time change according to the number of elements and their orientation?


Thanks to the digital light processing (DLP) technology used by EVERES, printing time is not dependent on the number or size of the printed elements, as every single layer is printed in a single instant. Hence, the only parameter affecting printing time in DLP technologies is the height of elements along the Z axis. As in all 3D printing techniques, the more work develops along the Z axis, the higher the number of layers that will need to be generated and as a result the longer it will take to complete the task.




What should be considered before printing?


Before launching a project with EVERES, the user should first consider the placement and orientation of the element on the printing base. This can be managed both automatically and manually with the SISMA EVESOFT proprietary software. With the stereolithographic printing technique, an element may require supporting for reasons of dimensional stability of the printed piece; this aspect can also be managed by EVESOFT, which provides an automatic support system. This type of support can also be controlled manually, by adding, removing or changing the types of supports and related connections.




What comes after the printing process?


EVERES Smart Building Platform allows the automatic detachment of the printed product, with no manual intervention on the platform required. Once removed, the piece may be cleaned from excess resin in a isopropyl alcohol bath, adding ultrasounds if required, to ensure more effective cleaning. Next, the supports may be removed from the piece with the specifically designed tools supplied by Everes. Finally, the printed element should undergo post-curing within a dedicated unit, according to the instructions included in the technical specifications of the resin used.




How is the printing base aligned at the bottom of the tank (reset)?


EVERES needs no manual resetting before printing. At the start of every printing task, EVERES automatically self-aligns the print base on the bottom of the printing tank. Once completed, the print base is locked in and remains aligned until the task is complete.




How should I manage the resin at the start and end of the printing process?


EVERES can manage the resin automatically at each printing cycle. During the preparation phase, a quantity of resin sufficient to carry out the selected task is automatically poured into the work chamber. At the end of the task, any excess resin will automatically be withdrawn inside the original cartridge, for optimum storage with no waste. Additionally, according to the type of resin used, users can select the thickness of layers with which they intend to build their model using the EVESOFT software. This setting may be changed manually and is the only one that users should consider when choosing the material, as the machine will automatically load the process parameters simply by placing the resin cartridge in the appropriate housing, thanks to RFID technology.




How can I control the printer?


All EVERES printers connected within "My local network" can be controlled by EVERES Monitoring Interface. This browser interface shows the status and printing phases of the units in the network, it also allows the management of the basic functions of the EVERES hardware (SBP, Hydraulic System, Tilting Glass and Door) to perform all standard printing operations. EVERES Monitoring Interface is a browser interface, hence it can easily be managed from any connected device, i.e. PC, tablet or smartphone.




What's the suction cup effect? What can I do about it?


All Bottom-Up Stereolithography techniques are affected by a mechanical effect on the printing element, the so-called "suction cup effect," due to the hydrodynamic properties of the resins used. This effect may be reduced with Zero Tilting Glass technology, patented by SISMA, combined with the PTFE membrane placed on the bottom of the printing tank. Zero Tilting Glass technology provides a mobile glass layer beneath the tank, which is automatically lowered every time the platform moves upward. This minimizes mechanical resistance, which will thus be due to the PTFE membrane only, hence minimized. Besides, the material that makes up the membrane is totally inert and will not degenerate when exposed to UV light and the resins used; as a result, this membrane is long wearing and the tank will not need to be replaced frequently.





SISMA S.p.A.

Via dell'Industria 1 

36013 Piovene Rocchette

Vicenza (VI) 

Italy

Hours

Mon - Fri: 08:30  - 12:30 

                     13:30 - 18:30
 

  • Facebook - Bianco Circle
  • LinkedIn - Bianco Circle
  • YouTube - Bianco Circle

© 2019 by SISMA S.p.A.

logo_Sisma_RGB.png