Additive Manufacturing Strategies

Binder Jet 3D Printing: Studying Print Speed & Effects on Surface Roughness & Density

ST Medical Devices

Share this Article

International researchers study different features that affect binder jetting, outlining their findings in the recently published ‘The Effect of Print Speed on Surface Roughness and Density Uniformity of Parts Produced Using Binder Jet 3D Printing.’ Binder jetting continues to be popular with industrial users because it is fast; however, that does not mean prints come out perfect, leaving the scientists here to work on methods for improving the overall outcomes of prototypes and parts.

Fabrication of a binder jetting part relies on:

  • Powder dispensing
  • Powder spreading
  • Binder dispensing
  • Binder drying

“The printing time (the time it takes to dispense binder droplets) can be decreased by either increasing the number of printing modules in the machine itself, or by increasing the speed at which the printhead traverses across the bed. However, increasing the printhead traverse speed can negatively affect the feature resolution and dimensional accuracy.”

Consistency is one of the most critical elements to production, and especially in manufacturing parts with close tolerances, however, the following issues can cause interruption to a good flow rate and consistency:

  • Machine wear
  • Machine cleanliness
  • The number of times powder is recycled
  • Humidity in the air

Schematic of the advanced compaction technology used during the powder spreading process.

For this study, the researchers investigated how powder speed will affect density of green body parts, long with surface roughness during sintering. They also explored how layer thickness and droplet size affect surface roughness. The research team 3D printed on an ExOne Innovent+ binder jet printer using the ExOne solvent binder at 70% saturation.

The build layout of each trial as shown in the Innovent+ software.

Five different coupon samples were sintered, measured, and weighed. Surface roughness was then measured five times.

a) Schematic of a coupon being tested 5 times in various positions across the surface of the coupon and b) schematic of the stylus traverse direction against layer thickness of angled coupons.

There were six printing trials in all, with each one of them demonstrating that increase of powder spread result in a density increase. Slow spreading speeds allowed for the greatest consistency in powder packing density.

“Although the coupons with the 50 μm layer thickness have a lower average green density than the 30 μm layer thickness, the coupons were able to sinter to over 98% dense,” stated the researchers. “When evaluating the effect coupon angle has on green density, the average density decreases with increased coupon angle.

“The surface roughness (Ra) typically increases with faster spreading speeds and increased coupon orientation angle,” concluded the researchers. “The smallest average surface roughness value (Ra) was found to be 4.05 μm with the 50 μm layer thickness and 30 pLa printhead on a flat surface with a spread speed of 3 mm/sec. The largest average roughness (Ra) was found to be 9.78 μm with the 50 μm layer thickness and 30 pL printhead on a 22.5° coupon with a 125 mm/sec spread speed.”

As researchers worldwide continue to study binder jet 3D printing, from use with materials like aluminum alloys to experimental powders, ceramic 3D printing, and more. What do you think of this news? Let us know your thoughts! Join the discussion of this and other 3D printing topics at 3DPrintBoard.com.

The average green density profile for each Trial in respect to coupon print angle.

[Source / Images: ‘The Effect of Print Speed on Surface Roughness and Density Uniformity of Parts Produced Using Binder Jet 3D Printing’]

Share this Article


Recent News

FDM 3D Printing Support Removal Times Cut in Half with VORSA 500

3D Printing Drone Swarms, Part 12: 3D Printing Missiles



Categories

3D Design

3D Printed Art

3D Printed Food

3D Printed Guns


You May Also Like

ICAM 2021: Keynotes on 3D Printing in Healthcare & Aerospace

At last month’s International Conference on Additive Manufacturing (ICAM) 2021 in Anaheim, California, hosted by ASTM International’s Additive Manufacturing Center of Excellence (AMCOE), a wide variety of topics were covered,...

Featured

3D Printing Unicorns: Gelato Gets $240M in Funding, Expands into 3D Printing

On-demand printing platform Gelato, based in Oslo, Norway, achieved the coveted unicorn status after a new funding round. On August 16, 2021, the company announced it had raised $240 million...

Featured

US Army and Raytheon to Use 3D Systems Metal 3D Printing to Heat-Optimize Munitions

3D Systems (NYSE: DDD) has been chosen by defense contractor Raytheon and the U.S. Army’s central laboratory to help with a design optimization project. To do that, the 3D Systems’...

Raytheon Receives Funding for Aerospace 3D Printing of Optical Components

This spring, Ohio-based America Makes, the leading collaborative partner in additive technology research, discovery, and innovation for the US, announced its latest Project Call for AXIOM, or  Additive for eXtreme Improvement...


Shop

View our broad assortment of in house and third party products.