Case Study: Analysis of 3D Printing on Textiles (TOC)
Introduction
SPS Product Engineering supports innovators from pre-development to prototyping to manufacturing, bringing product ideas to life. We specialize in developing products that fit the body in motion, including wearable technologies in industries from athletics to medicine and beyond.
Our process has four phases.
Configure
Test
Build
Scale
This case study examines the multi-phase testing process of 3D-printing directly onto a textile to strategically alter its functional properties. Our goal is to investigate textiles suitable for direct printing, particularly those fabrics that usually do not bond well. We aim to modify the mechanical properties of the fabric by applying different 3D patterns and understanding how these changes affect the material.
3D printing has revolutionized various industries, including aerospace, automotive, and healthcare. In recent years, niche pockets of creators have started to leverage this technology to create wearable applications that can significantly enhance functionality and aesthetics. In this SPS Lab Whitepaper, we analyze the current state of 3D printing on fabric, investigate its implications, and propose pathways for further research based on our findings.
By introducing non-standard materials outside of the realm of traditional garment making processes, our goal at SPS Product Engineering is to improve the intent and purpose of a textile, creating the opportunity for more customizable solutions for products that have high functional needs or depend on an elevated fit.
Textiles and 3D Printing
Treatments and special fibers can imbue textiles with additional properties to aid performance—even the type of thread twist can change the mechanics of a textile. However, all textiles have different mechanical properties that will limit performance.
Generally, if there are certain properties needed in a fabric, those properties are added to the whole of the cloth and not in specified areas. Although, through engineered knitting and other specialty processes, it is possible to achieve specific areas of different performance. Manipulation of weave, knit, or fiber structure are the main ways to define a textile and its mechanical properties. Introduction to new material, however, is limited based on machinery and is often constrained by other mitigating factors such as ease of cross-collaboration between industries and high set up costs for most development pools.
Companies like Stratasys have built textile 3D printing system (Fig 1). Other companies and designers such as Nike have experimented to 3D print full garments (Fig 2).
Figure 1: Stratasys 3D Printer
Figure 2: Nike Airmax 3D Printed Shoe
A common way that people print onto a fabric (if there is not a specialized machine, like the one from Stratasys) is by using netting, or perforated material. This makes it easier to have the print itself attached to the textile, via the negative space. However, this also means that the wearer will come into contact with the filament, as a base layer must be applied first for the textile to properly hold the print. This can result in abrasion against the skin, necessitating the use of a lining for the garment being created.
Fig 3.1, caption: Base layer of filament plus textile layer.
Fig 3.2, caption: Base layer of filament plus textile layer plus continued layers of filament.
We, however, wanted to see how difficult it would be to print onto a more opaque fabric without any form of transparency or negative space added.
Variables at Play
Because printing directly onto a textile is still a new practice, our investigation had multiple variables that needed testing in order to refine our findings and provide a recommendation.
Filament Variables
What is the optimal filament density, flow rate, and print pattern to improve performance without sacrificing the fabric’s properties?
Temperature Variables
Which temperature provides optimal performance when printed directly to a textile? Does environmental temperature affect the filament?
Textile Variables
Without using a mesh fabric, what type of textile adheres best to the filament at the optimal temperature/density?
Modifier Variables
Does the addition of a film modifier or substrate improve adhesion?
Fill Pattern Variables
Which print patterns, at which pattern densities, provide the best and most repeatable performance with the identified filament, temperature, textile, and modifier variables?
A systematic approach to product development
Each phase of testing at SPS Product Engineering builds on the findings of the previous phase, with an end result that has been tried and tested multiple times.
Materials and Equipment Used
Textile: Polyamide (Nylon)/Elastane
Similar in makeup to common filaments
Modifying substrates:
TPU films: Bidream Skinny, Shot 70, Shot 30 May provide an advantage to bond strength if needed
Filament: Varioshore TPU
Changes density of print material depending on temperature Can be adjusted to be hard and rigid or soft and flexible
Printer: Ender 3D Printer
Modified with direct extruder to allow ease of use with TPU filament
Provides better control and reduces power requirements
Additional Tools Used
Laser cutter
Stretch Test equipment
Varioshore TPU releases gas at higher temps and causes the material to foam, creating a softer TPU print.
Process
Setting up control factors in multi-phase exploration.
To begin the development process, first we identified the variables that we sought to standardize. Our multi-phase tests sought to identify:
Filament standards for final testing
Adhesion threshold
Substrate required, if any
Infill pattern types for final testing
Phase 1: Establish Filament Standards
Goal: Test the filament at different densities to identify the ideal temperature range for optimal adhesion for 3D printing onto the selected fabric.
Testing Filament Density and Performance: We printed Varioshore TPU filament with no added substrate at 190, 200, 210, 220, 230, 240, and 250 degrees Celsius.
Why Varioshore? A Tale of Two Densities
The Varioshore filament can be printed at different densities, changing how the printed pattern feels on the fabric. The denser print feels more rubbery and has a higher hardness, while the lighter density is more flexible and foam-like - changing how the swatch will stretch and recover. Varioshore TPU allows us to use one filament to test both print densities.
Testing the density variable provided an additional layer of knowledge in our experiments. Because we can use Varioshore to test multiple densities, infill patterns, and hardnesses, we’re able to use one filament for all tests, rather than seeking multiple filaments to test different densities.
It’s also a very interesting filament and allowed us to trial a material with room for unexpected findings to explore during our tests.
Results of Phase 1:
Highest effective density achieved at 190C
Lowest effective density achieved at 240C
Temperatures higher than 240C did show more softness but sacrificed filament performance and print consistency.
Varioshore TPU identified as filament of choice to optimize testing; otherwise multiple filaments would be needed.
Fig 3.3 – Cubes were printed in 10 degree increments to test wall thickness, flow rate, density, structure integrity. Doing sharp corners when there are different flow rates tends to highlight inconsistencies.
Phase 2: Establish Printing Process
Goal: Examine potential methods for adhesion, whether by temperature, or by adding an adhesive or grounding to the bottom of the print surface. Evaluate whether pattern type, size, or filament temperature had any positive effect on bond strength.
Testing for Best 3D Print Adhesion:
Infill pattern was tested at 25% density and 50% density.
Printed four sizes of swatch tested at all printing temperatures.
2"x2" Grid Pattern
3"x3" 3D Grid Pattern
5"x5" Cross Pattern
Each swatch was tested with a stretch and recovery test to examine how well the print bonded to the fabric.
Direct adhesion test with 3D structure.
Fig 5.2 video: Bare adhesion test with 3D structure.
Fig 5.3 video: Bare adhesion test with Cross Pattern.
Phase 3: Establish Ideal Process (and Substrate)
Goal: Identify substrates and patterns that yield the best results for stretch and recovery tests, finding a balance between an easy process and a substrate that doesn’t overshadow the properties of the fabric and 3D print.
Process Testing:
We evaluated multiple swatches with adhesive substrates using different print patterns, print densities, and print temperatures (filament density)
Evaluated various processes in applying substrate
Each pattern uses a different travel pattern for the printer, allowing us to examine whether certain travel paths on the fabric or substrate were more or less optimal
Patterns included Gyroid, Lightning, Grid, Cross, Honeycomb, Textile only (control), and Adhesion substrate only (control)
All patterns printed at 190C/374F (highest density) and 240C/428F (peak softness)
Results of Phase 2:
Bare fabric does not maintain adhesion if pulled hard enough. Substrate is needed for best performance.
Our testing process iterates forward! As we learn the limitations, we fine tune the approach until we can confidently move ahead with the next step in testing.
Phase 3: Establish Ideal Process (and Substrate)
Goal: Identify substrates and patterns that yield the best results for stretch and recovery tests, finding a balance between an easy process and a substrate that doesn’t overshadow the properties of the fabric and 3D print.
Process Testing:
We evaluated multiple swatches with adhesive substrates using different print patterns, print densities, and print temperatures (filament density)
Evaluated various processes in applying substrate
Each pattern uses a different travel pattern for the printer, allowing us to examine whether certain travel paths on the fabric or substrate were more or less optimal
Patterns included Gyroid, Lightning, Grid, Cross, Honeycomb, Textile only (control), and Adhesion substrate only (control)
All patterns printed at 190C/374F (highest density) and 240C/428F (peak softness)
Results of Phase 3:
After testing multiple patterns, we determined that Shot 30 substrate was the best performer for a permanent bond between the 3D print filament and textile that did not influence the textile in any major way.
The key of Phase 3 is to identify the ideal process for printing, which is why there are so many variables at play! We have to try a lot of approaches to start ruling out what doesn’t work.
Recap of Progress:
Phase 1 identified our ideal filament densities (190/240C)
Phase 2 determined that direct printing doesn’t perform well enough and substrate is needed.
Phase 3 identified the best performing substrate (Shot 30)
Phase 4: Stretch and Recovery Testing
Goal: Identify the best patterns for stretch and recovery, building on the results of all prior testing.
Simplified Stretch Test: Because of the number of variables being tested, we wanted the final test itself simple. The final stretch test involved stretch and recovery measurements in the warp direction only, and we compared test swatches to textile and substrate controls. Simplifying the dataset based on what we had already discovered in earlier testing made it easier to pin down the relevant findings for the development process.
Figure 7: A swatch being stretched with a 5 pound weight (out of frame at bottom).
Stretch Test Parameters
1. Create a 9"x15" swatch of each pattern and density
2. Stretch each swatch using a five pound weight
3. Verify original measurement of swatch
4. Measure growth after 15 minutes
5. Release weight and re-measure
6. Let rest for 15 minutes and re- measure
Tested Print Patterns: This phase narrowed down the print patterns to Gyroid, Cross, Grid, Lightning, and Honeycomb. Some patterns were chosen due to their similarity to common textiles, and others were chosen to test the capabilities of a multidirectional 3D print.
Gyroid pattern best resembled a knit structure.
Grid pattern resembles a weave pattern in filament form.
Honeycomb was chosen due to its resemblance to netting.
Cross pattern was chosen because its geometric shaping offered interesting properties; it also provided a good process test due to the multidirectional paths of the print.
Lightning was chosen to test how an unpredictable, organic multidirectional print would affect stretch and process.
Tested Filament Density: This final stretch test was done with both lower density filament (240C) and higher density filament (190C); the temperatures were selected because they provided optimal outcomes at two different densities, which gave us a variable to test. The 240C performed well; some of the hotter temperatures did provide a softer filament but required more upfront work on the printer and software settings, and the print integrity lost consistency.
Tested Pattern Density: We tested to identify a standardized pattern density that would work at both temperatures across all patterns. We found that the heat of printing affected how well each pattern printed at different sizes - for instance, a pattern that is dense and multidirectional had a harder time printing at 190C than 240C and vise versa.
Fig 8, caption: Pattern density selection for final stretch test.
Fig 9, caption: Swatch showing chosen pattern density of 25%.
Comprehensive Results
During testing, we recorded how each pattern influenced the fabric in stretch and recovery. In particular we examined:
A comparison of each print pattern type vs. textile alone
A comparison of stretch between pattern printed at 190C and 240C, using textile alone as a control factor
A comparison of stretch within time increments to examine integrity of each pattern’s resilience
Gyroid Pattern
Showed the most compression with good recovery
Compression was stronger in the vertical (warp) direction
The denser the pattern, the higher the compression*
Showed stretch but bounced back to original shape
*Though we did not explore varying pattern densities, we can still conclude that the denser the pattern, the higher the compression.
Cross Pattern
Some compression with varying recovery
Equal compression in multi-directions
240C print showed the most compression and 190C print showed less recovery
Stretched easily but less bounce-back recovery
Lightning Pattern
Both 190C and 240C prints had good, mid-level compression greater than that of the control textile alone
Only a slight compression difference between vertical and horizontal directions
Honeycomb Pattern
Varying levels of compression and stretch
Difficult to print on substrate without bubbling - a different pattern density or line thickness may benefit this specific pattern type better
240C sample showed compression and stretch closest to standalone textile
Grid Pattern
Slightly more compressive than standalone textile with the same recovery
Has more range of possibility, given the ease of the pattern (if the pattern density or line thickness were changed)
Different Patterns for Variable Compression Needs
If the goal of this project is to add more compression zones to a textile in a specific direction, Gyroid is our clear winner. However, if a mid-level compression element is needed, Lightning pattern shows promise with relatively good bounce-back in stretch and recovery tests. And if the need calls for a pattern that affected the textile equally in all directions, Grid or Cross may be the choice patterns, as their effect was multidirectional.
Fig 10-A: High Compression: Gyroid Pattern
Fig 10-B: Mid-Level Compression: Lightning Pattern
Fig 10-C: Multi-Directional Compression: Grid and Cross Patterns
Challenges and Limitations
Material Limitations: The range of materials suitable for 3D printing on fabric is generally limited, and not ideal. Additionally, filament materials that can perform the way textiles do regarding wash, wear, flex and breathability are lacking.
Adhesion Limitations: Even at high temperatures, the bond of 3D filament to textile came loose when given enough stress to the fabric. This could be circumvented with a bonding substrate added to the process, if the substrate chosen was balanced enough to be strong without affecting the textile more than the 3D print.
Scale of Production: While 3D printing offers customization in small-scale prototyping, work is still limited based on bed size. Producing any kind of large quantities in a cost-effective manner remains a barrier to widespread adoption. There are innovators out there working on this, but the technology isn’t here yet.
Technical Skills: The need for specialized skills in design and operation is another barrier. Understanding material interactions, method of application, and calibration of all parts can be a high-bandwidth pursuit.
An Opportunity for Partnership
We believe that cross-functional strategic partnerships between industries will help us bridge the gap between hard and soft product development and engineering. We’d love to partner with innovators who don’t believe in a one-size-fits-all approach.
Are you an industry expert? Reach out to us to discuss a collaborative partnership.
Conclusion
Broadly speaking, 3D printing holds the potential to enhance textile goods by introducing customization (protective or compression zones in a garment as an example) and innovative design (opening up the possibility to network 3D printed elements into a garment). Although its current uses are limited to highly customized or smaller scale projects, the continued development of 3D printing will have an evolving and transformative impact on textiles and wearables.
New filament types that aim for softness and wearability would benefit this transformation. As researchers, designers, and engineers collaborate, the possibilities for 3D-printing and textiles will become increasingly diverse, reshaping fashion, textiles, and wearable technologies.
Thorough testing for every project
Want to incorporate 3D printing into your soft goods offerings? SPS Product Engineering helps you find the ideal performance you and your customers can rely on. Book your consultation today.
SPS Client Success Stories
“I wouldn’t be in business without SPS.
“I had an idea for a product that I thought could improve women’s quality of life. Once I cobbled together an initial prototype, I looked for a partner to help me iterate and improve. From the moment I first met with SPS, I realized that they were the perfect partners to help me do just that. They walked me carefully through their process, making sure I was comfortable every step of the way. I had such confidence that they’d deliver on the product itself that I was able to focus on the other aspects of my business. SPS worked with me to create a high-quality product that I could scale and build a business around. I wouldn’t be in business today without them.”
Stacia Pache, Founder | itBandz
“Vast improvements on our original design.
“We create wearable medical devices that require a great amount of precision in their placement on the body. After initial talks with SPS about our project, it became clear that SPS had the design knowledge and (more importantly) the ability to listen to and understand our design needs, and working with their team has led to vast improvements to our original design. The prototypes were amazing and the new design is far beyond our expectations. The inventive designs from SPS show their deep knowledge of the human form and how it pairs with technical and mechanical requirements.”
Larry Pierce, CEO & Co-Founder | Precision Sensing SPC
“Without SPS, this product would not have come to fruition.
“We had a solution in our heads to a very specific problem in men’s running wear. We had the problem and market knowledge, but ZERO idea how to create our product. After speaking with SPS at length about our idea, goals, and background, I felt as though they had exactly the resources and expertise to help us through a completely unfamiliar (to us) process – they guided us through sketching, material procurement, patterning, prototyping, grading, and manufacturing. Every team member we have worked with has been not only capable, but engaged and excited about what we are trying to accomplish. Together, we are creating something completely new. Without SPS’s guidance, this product would not have come to fruition.”
Steph G & Thorin K | Percheron
Your success story here!
Our ingenuity powers your innovation – let’s talk shop. Contact us today to schedule a meeting.
References
Autodesk Instructables: How to 3D Print onto Fabric: https://www.instructables.com/How-to-3D-Print-Onto-Fabric/ Eurecat: https://eurecat.org/en/3d-printing-technology-infinite-length-formats-textile-industry/
Innovation Meets Medicine: https://www.3dsystems.com/customer-stories/innovation-meets-medicine-successful-cranioplasty-3d- printing?ind=medical
Nike Airmax 3D Printed Shoe: https://3dprintingindustry.com/news/new-nike-3d-printing-patent-236618/
Review on Development and Application of 3D Printing Technology in Textile and Fashion Design: https://www.mdpi.com/2079- 6412/12/2/267
Kaizen 3D Prints: https://www.youtube.com/watch?v=vJ8Gg0dPx0g
Sara Alvarez https://textile-academy.org/sara-alvarez-fabricademy-2020/
Stratasys 3D Printer: https://www.stratasys.com/en/resources/blog/direct-to-textile-3d-
Autodesk Instructables: How to 3D Print onto Fabric: https://www.instructables.com/How-to-3D-Print-Onto-Fabric/ Eurecat: https://eurecat.org/en/3d-printing-technology-infinite-length-formats-textile-industry/
Innovation Meets Medicine: https://www.3dsystems.com/customer-stories/innovation-meets-medicine-successful-cranioplasty-3d- printing?ind=medical
Nike Airmax 3D Printed Shoe: https://3dprintingindustry.com/news/new-nike-3d-printing-patent-236618/
Review on Development and Application of 3D Printing Technology in Textile and Fashion Design: https://www.mdpi.com/2079- 6412/12/2/267
Kaizen 3D Prints: https://www.youtube.com/watch?v=vJ8Gg0dPx0g
Sara Alvarez https://textile-academy.org/sara-alvarez-fabricademy-2020/
Stratasys 3D Printer: https://www.stratasys.com/en/resources/blog/direct-to-textile-3d-printing