3D Printing Infill Styles – the What, When and Why of Using Infill

Have you ever wondered about choosing a plain versus funky infill-style for filament 3D-printing? Amongst the ten standard types (no, the cat infill design is not one of them), some give you high strength, some greatly decrease material use or printing time, and others are purposely tailored with an end-use in mind.

IMG 2500

Highly detailed Insight slicing software from Stratasys gives you the widest range of possibilities; the basic versions are also accessible from GrabCAD Print, the direct-CAD-import, cloud-connected slicing software that offers an easy approach for all levels of 3D print users.

A part that is mimicking or replacing a metal design would do best when built with Solid infill to give it weight and heft, while a visual-concept model printed as five different test-versions may work fine with a Sparse infill, saving time and material. Here at PADT we printed a number of sample cubes with open ends to demonstrate a variety of the choices in action. Check out these hints for evaluating each one, and see the chart at the end comparing build-time, weight and consumed material.

image 2 6
Infill choices for 3D printed parts, offered with Stratasys’ GrabCAD Print software. (Image courtesy PADT Inc.)

Basic Infill Patterns

Solid (also called Alternating Raster) This is the default pattern, where each layer has straight fill-lines touching each other, and the layer direction alternates by 90 degrees. This infill uses the most material but offers the highest density; use it when structural integrity and super-low porosity are most important.

Alternating Raster Solid Back

Solid (Alternating Raster)

Sparse Raster lines for Sparse infill also run in one direction per layer, alternating by layer, but are widely spaced (the default spacing is 0.080 inches/2 mm). In Insight, or using the Advanced FDM settings in GrabCAD, you can change the width of both the lines and the spaces.

Sparse Double Dense As you can imagine, Sparse Double Dense achieves twice the density of regular Sparse: it deposits in two directions per layer, creating an open grid-pattern that stacks up throughout the part.

Sparse High Density Just to give you one more quick-click option, this pattern effectively sits between Sparse Double Dense and Solid. It lays rasters in a single direction per layer, but not as closely spaced as for Solid.

Hexagram The effect of this pattern looks similar to a honeycomb but it’s formed differently. Each layer gets three sets of raster lines crossing at different angles, forming perfectly aligned columns of hexagons and triangles. Hexagram is time-efficient to build, lightweight and strong in all directions.

Hexagram 3 Crossed Rasters Back
Hexagram
image 3 4
Additional infill styles and the options for customizing them within a part, offered within Stratasys Insight 3D printing slicing and set-up software. (Image courtesy PADT Inc.)

Advanced Infill Patterns (via Custom Groups in Insight)

Hexagon By laying down rows of zig-zag lines that alternately bond to each other and bend away, Hexagon produces a classic honeycomb structure (every two rows creates one row of honeycomb). The pattern repeats layer by layer so all vertical channels line up perfectly. The amount of build material used is just about one-third that of Solid but strength is quite good.

Hexagon Honeycomb Back
Hexagon

Permeable Triangle A layer-by-layer shifting pattern of triangles and straight lines creates a strong infill that builds as quickly as Sparse, but is extremely permeable. It is used for printing sacrificial tooling material (i.e., Stratsys ST130) that will be wrapped with composite material and later dissolved away.

Permeable Triangle Back
Permeable Triangle

Permeable Tubular This infill is formed by a 16-layer repeating pattern deposited first as eight varying wavy layers aligned to the X axis and then the same eight layers aligned to the Y axis. The resulting structure is a series of vertical cylinders enhanced with strong cross-bars, creating air-flow channels highly suited to tooling used on vacuum work-holding tables.

Permeable Tubular Back
Permeable Tubular 0.2 Spacing
IMG 2474
Permeable Tubular 0.5 Spacing

Gyroid (so cool we printed it twice) The Gyroid pattern belongs to a class of mathematically minimal surfaces, providing infill strength similar to that of a hexagon, but using less material. Since different raster spacings have quite an effect, we printed it first with the default spacing of 0.2 inches and then widened that to 0.5 inches. Print time and material use dropped dramatically.

Gyroid 0.2 Spacing Back
Gyroid 0.2 Spacing
Gyroid 0.5 Spacing Back
Gyroid 0.5 Spacing

Schwarz D (Diamond) This alternate style of minimal surface builds in sets of seven different layers along the X-axis, ranging from straight lines to near-sawtooth waves, then flipping to repeat the same seven layers along the Y-axis. The Schwarz D infill balances strength, density and porosity. As with the Gyroid, differences in raster spacing have a big influence on the material use and build-time.

Schwarz Diamond 0.2 Back
Schwarz Diamond 0.2 Spacing
Schwarz Diamond 0.5 Back
Schwarz Diamond 0.5 Spacing

Digging Deeper Into Infill Options

Infill Cell Type/0.2 spacing Build Time Weight Material Used
Alternating Raster (Solid) 1 h 57 min 123.77 g 6.29 cu in.
Sparse Double Dense 1 hr 37 min 44.09 g 4.52 cu in.
Hexagon (Honeycomb) 1 h 49 min 37.79 g 2.56 cu in.
Hexagram (3 crossed rasters) 1 h 11 min. 47.61 g 3.03 cu in.
Permeable Triangle 1 h 11 min. 47.67 g 3.04 cu in.
Permeable Tubular – small 2 h 5 min. 43.95 g 2.68 cu in.
Gyroid – small 1 h 48 min. 38.68 g 2.39 cu in.
Schwarz Diamond (D) – small 1 h 35 min. 47.8 g 3.04 cu in.
Infill Cell Type/0.5 spacing Build Time Weight Material Used
Permeable Tubular – Large 1 h 11 min. 21.84 g 1.33 cu in.
Gyroid – Large 57 min. 20.59 g 1.29 cu in.
Schwarz Diamond (D) – Large 58 min. 23.74 g 1.51 cu in.

Hopefully this information helps you perfect your design for optimal strength or minimal material-use or fastest printing. If you’re still not sure which way to go, contact our PADT Manufacturing group: get your questions answered, have some sample parts printed and discover what infill works best for the job at hand.

PADT Inc. is a globally recognized provider of Numerical Simulation, Product Development and 3D Printing products and services. For more information on Insight, GrabCAD and Stratasys products, contact us at info@padtinc.com.

Categories

Get Your Ansys Products & Support from the Engineers who Contribute to this Blog.

Technical Expertise to Enable your Additive Manufacturing Success.

PADT’s Pulse Newsletter

Keep up to date on what is going on at PADT by subscribing to our newsletter.


By submitting this form, you are consenting to receive marketing emails from: . You can revoke your consent to receive emails at any time by using the SafeUnsubscribe® link, found at the bottom of every email. Emails are serviced by Constant Contact

Share this post:

Upcoming Events

03/28/2024

SAF Blue Carpet Event

03/28/2024

2024 Arizona Space Summit

04/03/2024

Low Frequency Updates in Ansys 2024 R1 - Webinar

04/03/2024

Venture Madness Conference Reception + Expo

04/03/2024

Stratasys F3300: Game Changing Throughput - Webinar

04/08/2024

39th Space Symposium

04/09/2024

39th Space Symposium

04/10/2024

Discovery Updates in Ansys 2024 R1 - Webinar

04/10/2024

39th Space Symposium

04/11/2024

39th Space Symposium

04/22/2024

Experience Stratasys Truck Tour: Houston, TX

04/24/2024

Structures Updates in Ansys 2024 R1 (2)

04/24/2024

Experience Stratasys Truck Tour: Houston, TX

05/07/2024

Experience Stratasys Truck Tour: Albuquerque, NM

05/08/2024

Fluent Materials Processing Updates in Ansys 2024 R1 - Webinar

05/09/2024

Experience Stratasys Truck Tour: Los Alamos, NM

05/14/2024

Simulation World 2024

05/15/2024

Simulation World 2024

05/16/2024

Simulation World 2024

05/22/2024

Optics Updates in Ansys 2024 R1 - Webinar

06/12/2024

Connect Updates in Ansys 2024 R1 - Webinar

06/26/2024

Structures Updates in Ansys 2024 R1 (3) - Webinar

06/27/2024

E-Mobility and Clean Energy Summit

07/10/2024

Fluids Updates in Ansys 2024 R1 - Webinar

08/05/2024

2024 CEO Leadership Retreat

10/23/2024

PADT30 | Nerdtoberfest 2024

Search in PADT site

Contact Us

Most of our customers receive their support over the phone or via email. Customers who are close by can also set up a face-to-face appointment with one of our engineers.

For most locations, simply contact us: