Flexible 3D Printing, Rebuilt for Production: Inside Siraya Tech’s TPU and PEBA Ecosystem

Flexible filaments have always been the materials engineers reach for when a part has to survive something – vibration, impact, repeated deflection, chemical exposure. They have also, historically, been the materials engineers dread printing. Slow, stringy, warp-prone, and available in a narrow band of hardnesses that rarely matched the application.

Siraya Tech’s flexible ecosystem is built around a different premise: that a soft-material lineup should behave like an engineering catalog, with a defined property ladder, published print profiles, and a clear reason to choose one grade over the next. This article maps that lineup – what each material does, where it wins, and how to select between them.

How the Lineup Is Organized

Two base chemistries, three engineered modifications. Everything in the ecosystem is a combination of the two.

Base Chemistries

• TPU – thermoplastic polyurethane. The workhorse: broad durometer range, excellent abrasion and tear resistance, wide printer compatibility.
• PEBA – polyether block amide, sold under the Rebound product name. Lighter, dramatically higher energy return, and functional at temperatures where TPU stiffens badly.

Modifications

• Air – active foaming. Cell structure develops during extrusion, cutting part weight and making effective durometer tunable via nozzle temperature.
• GF – glass-fiber reinforcement. Adds stiffness and dimensional stability while retaining elastomeric behavior.
• HR – high-rebound hybrid tuning, sold under the Roamr product name. A foamed TPU formulated to approach PEBA-class rebound.

The entire ecosystem is compliant with REACH and RoHS. The TPU grades and Roamr series have been tested to ISO 10993 for biocompatibility (parts -5 and -10); TPU-GF testing is currently in progress.

Material Selection Guide

Materials are listed by base chemistry and durometer. Product names appear alongside.

Rigid, Dimensionally Stable, and Still Elastomeric

The gap in most soft-material catalogs sits between TPU and engineering plastics. Standard TPU lacks the stiffness for a load-bearing bracket; rigid nylons and PET-CF absorb no shock and transmit every vibration into the assembly around them.

TPU 64D closes part of that gap on its own – firm enough for gears and rollers, elastomeric enough to survive shock loads that would crack a rigid part.

TPU-GF 67D goes further. Built on the TPU 64D base and reinforced with 15% precisely cut glass fiber, it delivers dimensional stability and warp resistance that unreinforced TPU cannot, while retaining the vibration absorption that makes TPU worth using in the first place. In practice this is the grade for RC chassis brackets, motor mounts, and structural frames that see continuous mechanical stress.

Glass fiber is abrasive. TPU-GF 67D requires a hardened nozzle.

Energy Return: The Property that Separates PEBA from TPU

Toughness and rebound are different things. A material can absorb an impact by deforming permanently – that is toughness, and it works once. Energy return is what the material gives back.

Rebound PEBA returns 78% of input energy. It absorbs a hard strike and springs back without plastic deformation, then does it again. It stays flexible down to -60 °C, where standard TPU has stiffened well past useful, and it resists chemical attack and fatigue cycling. It is also 15–20% lighter than TPU at equivalent durometer, which compounds the advantage in any application where mass is a penalty.

That combination is why PEBA shows up in drone bumpers and frames, protective equipment, and dynamic robotics components – parts that take repeated impact and have to be light.

Roamr TPU Air HR sits deliberately between the two chemistries: a foamed TPU tuned for high rebound, aimed at insole and midsole applications that need walking comfort and spring-back from the same part. It is the lower-cost path to rebound behavior when full PEBA performance is not required.

Throughput: Printing Flexibles at Production Speed

Soft materials have been slow because soft filament buckles under drive pressure and melt viscosity climbs at speed. TPU 95A HF is reformulated for flow, reaching volumetric rates up to 15 mm³/s – several times what conventional TPU tolerates on most direct-drive systems.

The practical result is that a soft part no longer sets the pace of a build plate. Batch runs of seals, dampers, or wearable components complete in a fraction of the previous time, with layer adhesion maintained across the speed range.

Print quality on flexibles is a function of profile, not luck. Siraya Tech publishes factory-tuned parameters for every grade in the lineup rather than asking users to derive them.

Lightweighting and Tunable Hardness

The Air grades use active foaming: gas generation during extrusion creates a cellular structure inside the extrudate. Two consequences follow.

The first is weight. TPU Air 95A produces parts up to 50% lighter than the same geometry in solid TPU 95A – relevant anywhere a part is worn, carried, or flown.

The second is more unusual: effective hardness becomes a print setting. Raising nozzle temperature increases foaming, lowering density and softening the part. TPU Air covers 65A–82A, TPU Air 95A covers 75A–95A, and Rebound PEBA Air covers 70A–95A – each from a single spool. A designer can tune a wearable’s comfort zones, or iterate through durometers on an insole, without buying new material.

Applications span professional and creative work: orthotic and insole applications, ergonomic wearables, protective padding, lightweight drone components, and cosplay armor and props where large parts need to stay wearable.

Note for regulated applications: Siraya Tech’s TPU grades are tested to ISO 10993-5 and -10 for cytotoxicity and irritation/sensitization. Any medical device, orthotic, or patient-contact application remains subject to the manufacturer’s own regulatory qualification.

Color as a Production Variable

TPU Air ships in seven colors, and the broader ecosystem carries a professional palette – but for production users the argument is not aesthetic. Consistent, saturated color at the spool means end-use parts ship straight off the build plate. No painting step, no dyeing, no batch-matching between production runs.

Specifications, Profiles, and Evaluation

• Technical Data Sheets
• Factory print profiles
• Official website
• Amazon Store (US)
• Amazon Store (DE)
• Technical questions: support@siraya.tech

About Siraya Tech

Founded in 2019 and headquartered in Los Angeles, Siraya Tech develops high-performance materials for additive manufacturing across photopolymer resins, platinum silicones, and functional filaments. The company’s focus is bringing production-grade material performance within reach of the engineers, manufacturers, and makers actually building with it.