How about developing 3D printable conductive filaments with inherent sensing capability? Voila, scientists from US-based Purdue University have invented a way to evenly disperse sensing particles into fused deposition modeling filaments. This can then be 3D printed into functional electronic parts such as sensors. The conductive sensing particles are carbon nanofibers diffused in a thermoplastic polyurethane carrier resin via a wet mixing process. The electrical conductivity levels are tunable by altering the weight percentages of the 100-nanometer diameter carbon nanofibers.
3D Printing Process for Conductive Filaments in Fully Functional Parts by Purdue University
The market size of conductive polymer technologies is expected to grow in the coming years.
- Electrically conductive plastics have a current global market size of 3.75 billion US dollars and are forecast to grow 8.5% annually over the next five years.
- The current global graphene market is estimated at 110 million US dollars and will grow at 40% annually over the next five years.
- The current global thermally conductive plastics market is 130 million US dollars, with a 15% growth rate over the next five years.
End-use Applications are Driving Electrically Conductive (L), Graphene Conductive (C), and Thermally Conductive (R) Optimized Compound Development
Let’s review two thermally, one graphene, and two electrically conductive polymer technologies, respectively.
LANXESS’ Thermally Conductive PA6 for Electric Car Charge Controller
Durethan® BTC965FM30 compound by LANXESS is a thermally conductive and electrically insulating polyamide 6 (PA6). Currently used in high-performance EV sports car microsized charge controller. The charge controller modulates high speed and requires:
- Intensive electrical charging (48 amp) charging from an electrical charging station grid outlet to the EV’s battery.
- A combination of thermal conductivity dissipation to control overheating harnessed to flame retardant electrical insulation is required.
LANXESS’ Thermally Conductive PA6 Cooling Element (R) for Electric Sports Car Charge Controller
Furthermore, a good PA6 thermal conductivity critically centers on:
- strict flame-retardant properties,
- low tracking of arc resistance, and
- mechanically tough injection molded part design.
Special mineral heat-conducting additives undisclosed by LANXESS give the PA6 compound an in-plane thermal conductivity of 2.5 W/(m-K) (Watts per meter-Kelvin) and 1.3 W/(m-K) through a plane.
Huber’s MARTINAL® Thermal Interface Materials for EV Battery
Huber Engineered Materials has developed, up to 90 wt% MARTINAL® TM (Thermal Management) aluminum hydroxide additive grade for plastic resin compounding with polyurethanes, epoxy, silicone, and acrylic, application targeted as thermal interface materials (TIMs) to control electric vehicle (EV) battery thermal conductivity. Huber estimates that up to 5 liters of TIMs go into an average EV battery pack.
In addition to excellent thermal conductivity Huber’s MARTINAL® aluminum hydroxide additive:
- prevents battery overheating failure,
- inherently flame retardant, and
- is a cost-reducing compound when compared to traditional metal-filled systems.
With reducing overall EV battery pack manufacturing costs, the EV mileage range is dramatically extended.
Huber’s Thermal Interface Materials (in Black under White Battery Elements) for EV Battery Pack
OCSiAl’s Graphene Conductive Nanotubes for Medical Devices
OCSiAl’s graphene nanotubes are now compounded into heat-cured rubber (HCR) for use in European REACH approved medical electronic massage ball treatment devices. As conductive additives, graphene nanotubes outperform competitive carbon black and silver additive systems in terms of the former’s challenge of creating skin contact contamination, and the latter’s lack of compound mixing and processing uniformity.
Also, graphene nanotube incorporation maintains rubber flexibility and softness critical to device use, at low 0.25 wt% dosage rates, in turn replacing older used 40 wt% carbon black systems.
OCSiAl’s Graphene Nanotube HCR Medical Massage Ball (Black Sphere on Neckline)
Premix’s Electrically Conductive Range for Tubing Application
Since the 1980s, Finland’s Premix has long emphasized the development of carbon black in their world market-leading, broadly based on PRE-ELEC® line of conductive plastic compounds that operate in the that operate in the 102-106 ohm core surface resistivity range. When used in flexible conduit tubing mechanical toughness, high flexibility, and superior abrasion resistance is very cost-performance optimized for very durable, long-lasting service life.
Premix’s Electrically Conductive PRE-ELEC® Compound Range (L), Tubing Application (R)
OCSiAl’s Electrically Conductive Carbon Nanotubes for Automotive Parts
OCSiAl’s TUBALL™ Single-Wall Carbon Nanotubes (SWCNT) when compounded into non-electrically conductive automotive plastic parts allow for direct inline painting. This lowers the cost as compared with conductive spray-painted metal parts. Carbon black is commonly used here, but at high addition rates, it comes with a sacrifice in maintaining mechanical properties.
OCSiAl’s TUBALL™ MATRIX 822 SWCNT at 0.1 wt% of nanotubes has been compounded into PA, filled PPS, ABS, TPU, and PC resin systems.
- Delivering surface resistivity of 105–109 ohm surface resistivity over broad low-to-high paint oven temperature ranges.
- It is also cost-effective and superior to Multi-Wall Carbon Nanotubes (MWCNT).
OCSiAl’s TUBALL™ SWCNT (Blue Line) versus MWCNT (Gray Line) and Carbon Black (Black Line)