Carbon Nanotube Masterbatches

What are Carbon Nanotube Masterbatches?

Carbon Nanotube Masterbatches are pre-dispersed concentrates of multi-walled carbon nanotubes in a thermoplastic carrier polymer, supplied as ready-to-extrude pellets. Each pellet contains a known weight percentage of well-dispersed CNTs in the same base polymer you intend to use in your final part — so you simply blend the masterbatch with virgin polymer to reach your target conductivity, then process on standard extrusion or injection molding equipment. The masterbatch approach eliminates the dispersion challenges, dust hazards, and lot-to-lot inconsistency that come with handling neat CNT powder in a production environment.

Why Masterbatches Beat Neat CNT Powder for Production

Loose CNT powder is notoriously difficult to disperse uniformly in thermoplastic melts. Achieving full percolation requires high shear, often custom screw geometries, and careful temperature control — and even then, agglomerates routinely survive into the final part, creating localized resistivity hot spots and weak points. Masterbatches solve this with a controlled dispersion step done once at the manufacturer:

• Consistent loading — every pellet contains the same CNT concentration, so blending is predictable to within ±10% of target
• No agglomerates — high-shear compounding with optimized screws fully exfoliates the CNT network before pelletizing
• No inhalation hazard — fiber-bound CNTs in pellet form eliminate the airborne dust risk that loose CNT powder presents in a production facility
• Standard processing — the masterbatch processes on the same extruder or injection molder as the carrier polymer, with no special equipment
• Faster development cycles — dial in the final loading by adjusting the let-down ratio rather than re-running compound trials

Available Carrier Polymers

Cheap Tubes supplies CNT masterbatches in five carrier polymers, selected to match the most common engineering and commodity thermoplastic applications:

Carrier Polymer	Typical CNT Loading	Common Applications
Polystyrene (PS)	15 to 20 wt% CNT	Antistatic packaging, EMI-shielding consumer enclosures
Polycarbonate (PC)	10 to 15 wt% CNT	ESD-safe electronics housings, optical-grade conductive parts
Polypropylene (PP)	15 to 20 wt% CNT	Automotive fuel-system components, conductive containers
Polyamide 6 (PA 6)	10 to 15 wt% CNT	Antistatic gears, electrical connectors, structural parts
ABS	10 to 15 wt% CNT	EMI shielding for electronics, conductive automotive trim

Custom carrier polymers (TPU, PEEK, POM, and bio-polymers) and custom loading levels are available on request for project work and pilot scale-up.

Typical Use — Calculating the Let-Down Ratio

To reach a target CNT loading in the final part, calculate the let-down ratio as: (final wt% target) ÷ (masterbatch wt%) = mass fraction of masterbatch in the blend. For example, to reach 1.5 wt% CNT in a final PP part using a 15 wt% CNT masterbatch, blend the masterbatch at 10% with 90% virgin PP. Most antistatic applications need 0.5 to 2 wt% final CNT loading; EMI shielding typically needs 3 to 7 wt%; structural reinforcement applications target 1 to 3 wt%.

Applications Where Masterbatches Make Sense

• Antistatic and ESD-safe plastics — packaging, IC trays, electronics enclosures, semiconductor handling
• EMI shielding plastics — consumer electronics housings, medical device enclosures, automotive sensor housings
• Conductive automotive components — fuel system parts, fuel tank liners, conductive trim, anti-static body panels
• Industrial conveyor and tooling parts — conductive bearings, bushings, and wear surfaces in dust-sensitive environments
• Conductive films and sheets — extruded films for shielding bags and conductive flooring

Documentation and Ordering

Every masterbatch order ships with a Technical Data Sheet listing the carrier polymer grade, CNT type and outer diameter, target CNT weight percentage, recommended processing conditions (melt temperature, screw configuration, residence time), and recommended let-down ratios for typical end-application loadings. A current Safety Data Sheet is included. Certificate of Analysis is available on request and includes the as-measured CNT loading, dispersion uniformity (verified by SEM), and Raman spectrum of the compounded pellets.

Standard pricing covers 1 kg to 25 kg orders for development work. Production-quantity pricing (>100 kg) is quoted on request — we ship from Vermont and most stock orders go out within 5 business days. Custom carrier polymer formulations and custom CNT loadings are quoted with a 2 to 4 week development lead time.

Frequently Asked Questions