PA6·PA66 How to manage CNT dispersion and moisture in ESD compounds

Problem

ESD and conductive performance depends on the network formed in the final part or coating, not on the filler name alone. Resin, dispersion, loading, flow, thickness, humidity, and measurement geometry can shift resistance substantially.

Mechanism

Conductive particles must form a connected network across the relevant geometry. Network continuity can be changed by agglomeration, selective phase location, shear, orientation, weld lines, dilution, curing, or post-molding relaxation.

Tradeoff

Moving farther above the percolation threshold can stabilize resistance but may reduce impact strength, elongation, color freedom, surface quality, viscosity, or processability. Qualification must cover both electrical distribution and non-electrical requirements.

Material Strategy

Use the following decision sequence to define the host system, compare candidate materials, establish a process window, and confirm the final part. The guidance is method-conditioned and does not replace grade-specific data or application testing.

key answers

ESD For a practical review of CNT additives for PA6·PA66, it is not sufficient to compare only the product name or supplier representative figures. First, the required functions of the final part or film, acceptable appearance and processing range, and actual test conditions must be defined. Then, candidate materials must be compared under the same base material, thickness, process, and conditioning conditions to obtain meaningful conclusions.

This page does not claim that any particular grade is superior to all systems. The function of the material depends on the resin or binder, particle dispersion, addition amount, shape, process and measurement method. Before purchasing, you must check what composition, test specimen, and method the values ​​in the technical data were obtained from, and conduct an evaluation that reflects actual mass production conditions.

Resin Polarity and CNT Wetting

‘Resin polarity and CNT wetting’ are key process variables that determine final performance. Do not judge the dispersibility solely based on the primary particle size of the powder, but also review the actual aggregate size, surface treatment, and compatibility of the dispersant, resin, or solvent. Even if the concentrate appears stable, it can reagglomerate during binder addition, dilution, curing, or storage.

In comparative tests, the dosing sequence, mixing energy, temperature, time and batch size are fixed. Viscosity, particle size or filter residue, as well as functional values ​​of the final coating or molded part, must be measured to determine if the dispersion process has actually improved.

Effects of dryness, moisture, and viscosity

The ‘drying, moisture, and viscosity effects’ items cannot be separated from material evaluation. Equipment type, screw or mixer, feeding sequence, temperature, shear, residence time, drying and cooling conditions change particle distribution and final function. This is a common reason why compositions that are successful in the laboratory do not produce the same results in mass production equipment.

In the test report, not only the name of the material but also the process conditions and specimen production history are recorded. Before mass production, batch size and equipment are expanded step by step, and changes in viscosity, pressure, torque, appearance, and functional values ​​are compared at each step.

Interaction of GF with CNT

The item ‘Interaction of GF with CNT’ should be treated as an independent decision-making criterion for the CNT additives for ESD PA6·PA66. First, target values, measurement methods, allowable deviations, and failure criteria are documented and then candidate materials are compared. If conditions are not fixed, it is difficult to distinguish between material differences and test deviations.

Evaluation results include not only average values but also repeated measurements and ranges. When the goal is not met, the cause is identified by separating additives, base material, dispersion, process, specimen shape, and measurement conditions in that order.

Surface/volume resistance classification

In the ‘Surface/Volume Resistance Classification’ section, it is dangerous to pass a material with only a single resistance value. The conductive network is affected not only by the amount added, but also by filler distribution, flow direction, specimen thickness, measurement location, humidity and thermal history. Especially in the sections before and after percolation, small process deviations can lead to large resistance deviations.

First determine whether surface resistance, volume resistance, or ground resistance describes the actual risk of use. It can be used as a supply specification only when repeated measurements are made under the same conditioning and electrode conditions, and the molding location, direction, and distribution by lot are recorded.

Resistance stability after heat aging

In the ‘resistance stability after heat aging’ section, it is dangerous to pass a material with only a single resistance value. The conductive network is affected not only by the amount added, but also by filler distribution, flow direction, specimen thickness, measurement location, humidity and thermal history. Especially in the sections before and after percolation, small process deviations can lead to large resistance deviations.

First determine whether surface resistance, volume resistance, or ground resistance describes the actual risk of use. It can be used as a supply specification only when repeated measurements are made under the same conditioning and electrode conditions, and the molding location, direction, and distribution by lot are recorded.

Recommended Evaluation Procedure

1. Target functions and failure conditions are defined by numerical or observation criteria.
2. A standard specimen is created using the base material, additive package, and substrate that will be used in mass production.
3. Rather than changing all variables at once, compare material types, addition amounts and key process conditions step by step.
4. In addition to initial functionality, appearance, processability, mechanical or adhesive properties and required durability are measured.
5. The optimal conditions are repeated on different raw material lots, on different dates, and in actual production facilities to confirm the process window.

The test report includes the name of raw materials, lot, mixing, specimen thickness and shape, equipment, temperature, time, speed, conditioning, and measurement method. Without this information, it is difficult to fairly compare results between suppliers or between lab and mass production.

Information to provide to suppliers

• Exact type and grade of base resin, binder or substrate
• Target function value, measurement method and tolerance range
• Limitations on color, transparency, surface, viscosity or mechanical properties
• Mixing, extrusion, injection, application, drying or curing conditions
• Thickness, shape and usage environment of specimens and final parts
• Required TDS, SDS, regulatory documentation and change management level
• Evaluation sample quantity, development schedule and expected mass production scale

Frequently Asked Questions

Can I select a grade based solely on representative values from the datasheet?

Representative values are useful for narrowing down candidates, but are insufficient as a basis for final selection. If the test composition, method, thickness and conditions are different from the actual system, the same results cannot be expected.

Is the highest dosage safest?

Not really. Higher additions may increase functionality but may worsen viscosity, torque, brittleness, color, haze, surface or cost. We need to find the minimum range that reliably satisfies the goal.

Can laboratory results be directly applied to series production?

Equipment size, shear, residence time, heat history and part geometry will vary and should not be applied without confirmation. It must be re-verified step by step in pilot and mass production facilities.

Request evaluation samples and technical reviews

Please submit nylon grade, GF content, target resistance and environmental conditions. Please include the above input information with your request. The more specific the information, the faster you can narrow down the appropriate supply form - powder, masterbatch, or dispersion - and reduce unnecessary repetitive testing.

Recommended Architectures

• Use a matched baseline with the intended host resin, binder, substrate, color package, thickness, and geometry.
• Screen supplied form, loading, dispersion, and process variables in a bounded matrix.
• Advance only candidates that meet functional, processing, appearance, mechanical, and durability requirements together.
• Repeat the accepted window on production-relevant equipment and multiple raw-material lots.

Related Products

• MWCNT
• SWCNT
• GNP
• ATO

Related Applications

• ESD Materials
• Conductive Plastics and Coatings

Downloads & Engineering Support

Review the related Dispersion Engineering Overview Video, then request an application-specific technical review.