New Thermoplastic Success with Additive Manufacturing

TPE-SEBS (Thermoplastic Elastomer - Styrene Ethylene Butylene Styrene), is a high-performance elastomeric material with very good rubber like properties and desirable haptic feel. It is currently used in everything from hammer grips and toothbrushes to seals in electronics and automotive applications due to its excellent tensile set, compression set, low moisture up-take, and tactile feel.

While this material is superior in its elastomeric characteristics, it has not been an easy material to work with in additive manufacturing processes—until now. Jabil has refined its TPE-SEBS filaments so they can be 3D printed more reliably with a higher success rate than more common industrial materials like thermoplastic urethane (TPU).

TPU’s are hygroscopic so they tend to absorb moisture at ambient conditions leading to a high failure rate when printing. TPE-SEBS, however, is non-hygroscopic, enabling the design freedom expected when designing and producing parts with FFF3D printing.  TPU and past versions of TPE-SEBS would experience print failures during the printing process due to the parts shrinking as the layers are accumulated. As the part is being built, the shrinking caused the part to curl on the build plate known in the field as “potato-chipping”. This causes print failures as well as lost time and productivity, not to mention the cause of a lot of frustration for the user.

At the Jabil Materials Innovation Center, we determined that other manufacturers’ attempts at 3D printing TPE-SEBS treated the material as though it was still processed via conventional injection molding. There was no real fundamental understanding of the base polymer properties and how that polymer would behave in a 3D printing environment.

To successfully print TPE-SEBS, a detailed analysis of the polymer chemistry and printing process was needed. The approach of using polymer science and system integration onto multiple open 3D printing platforms was critical to resolving these issues (as it is for most 3D printing material development). System integration is a process to validate the effects of polymer modification on physical properties and printing performance. System integration is required to measure results and drive iteration in the development of a well-designed, robust material.

Our materials engineers determined a list of polymer composition, behavior and the effects of the process variables to consider for success:

  • How the material pools
  • How the material shrinks
  • How the material solidifies
  • The crystallization kinetics as it extrudes and cools
  • CLTE (Coefficient of Linear Thermal Expansion)
  • Molecular Weight
  • Additives and fillers

To achieve successful 3D printing of TPE-SEBS, we were able to leverage Jabil’s polymer science and system integration expertise to better understand the root cause of the print failures. Using this approach, we identified the CLTE of the material as a primary factor. Our Jabil team used polymer science principles to modify the base polymer to reduce its CLTE and system integrate those results on multiple, open-platform 3D printers to confirm our results. We were able to take this insight on the polymer chemistry of TPE-SEBS and ultimately resolve the root cause of the printing issues.

New Applications for 3D Printing

The ability to produce TPE-SEBS parts through additive manufacturing is a significant development. With an elongation of over 500% and flex fatigue resistance, TPE-SEBS can survive millions of repetitive cycles for applications that require living hinges, squeak, rattle and vibration, and seals in automotive applications. Its low hygroscopic qualities make it an attractive option in electronics housing seals in cell phones and other devices. TPE SEBS also has a desirable haptic and tactile feel that will only increase its adoption in soft-touch grips on items such as cordless drills, screwdrivers and kitchen utensils. The high CoF (coefficient of friction) of this material might even find a home in some unusual applications such as the tires of remote-controlled cars and aircraft.

Flexible, tensile quality of TPE-SEBS Because of its superior properties, adoption and usage of this material is rising fast. We’ve talked to several different manufacturers and OEMs who have shared that TPE-SEBS is quickly becoming their “go-to” material for elastomeric or flexible applications. It’s understandable, considering the significant benefits that additive manufacturing has to offer. It can cut tooling costs dramatically when compared to injection molding and enable more freedom in parts design due to the flexibility of the platform. It also enables a distributed manufacturing model that can cut the inventory needed on-hand by enabling on-demand, local inventory replenishment. Look for 3D printed TPE-SEBS to become widely adopted across a range of industries as more companies realize the cost and time advantages of additive manufacturing and the ease and reliability of a flexible material that can be easily printed into complex parts.

Shop and purchase Jabil TPE-SEBS on Digi-Key today.

 

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