EMS-Grivory Grilamid LV-23 ESD is a dry-as-molded polyamide 12 injection-moulding grade containing 23% glass fibre by mass and an electrostatic-dissipative filler system. The grade designation identifies the base polymer, reinforcement level, and electrical function: the glass fibre content is fixed at 23%, while the ESD suffix indicates reduced surface and volume resistivity relative to unfilled or purely glass-filled PA12. The material is supplied as pellets with a moisture content specified by EMS-GRIVORY to remain below 0.10% by mass when stored in sealed moisture-barrier packaging. The dry condition referenced in the product name is not equivalent to the moisture-conditioned state defined in ISO 1110 at 23 °C and 50% relative humidity. Dry data reflect the polymer before significant moisture uptake; conditioned data represent equilibrium moisture uptake at standard atmosphere.

The density of the dry compound is published at approximately 1.20 g/cm³ under ISO 1183-1. The combination of PA12 with 23% glass fibre produces a stiffness, strength, and dimensional-stability profile that is distinct from unfilled PA12 and from short-glass PA6 or PA66 grades. The PA12 matrix contributes low moisture absorption, low-temperature impact behaviour, chemical resistance, and lower density than PA66 at comparable reinforcement. The glass fibre raises tensile modulus, reduces isotropic shrinkage, and lowers creep under load. The ESD filler further modifies electrical surface properties and must be considered during processing because shear history, moisture, mould fill speed, and weld-line formation affect the final charge-dissipation performance.

What distinguishes the 23% glass-fibre reinforcement in a dry PA12 matrix from standard ESD thermoplastics?

In dry-as-moulded form, the reinforcement dominates the short-term mechanical response. The tensile modulus of Grilamid LV-23 ESD is in the range of approximately 4,000–4,500 MPa when measured according to ISO 527-1/-2 at 23 °C. Tensile strength at break is typically between 60 MPa and 75 MPa in the dry state. Elongation at break is constrained by the glass fibre and is typically below 5%. The notched Charpy impact strength under ISO 179-1/1eA is moderate, generally from 4 kJ/m² to 6 kJ/m² dry, because the glass reinforcement restricts large plastic deformation. Heat deflection temperature under 1.80 MPa load is generally near 60 °C, while the 0.45 MPa value is substantially higher and reflects the crystalline PA12 melting region.

The dry condition produces higher stiffness and lower elongation than the conditioned state. After moisture uptake to equilibrium at 23 °C and 50% relative humidity, PA12 absorbs less water than PA6 or PA66, so the shift in modulus and yield stress is smaller. The moisture-induced plasticisation of the PA12 matrix can increase notched impact toughness and reduce tensile modulus, but the glass fibre limits the magnitude of the change. For the ESD grade, moisture also alters the electrical dissipation mechanism because water uptake affects the surface resistivity and charge-decay behaviour of the polymer-filler interface. Published data for this specific configuration is limited, and electrical performance should be confirmed on dried mouldings for applications operating below 30% relative humidity or after prolonged exposure to humid air.

The practical relevance of the dry state is most visible in thin-wall structural components, clips, housings, and fixtures that must maintain dimensional control after moulding. The glass fibre reduces mould shrinkage to a range of approximately 0.1–0.4% in the flow direction and 0.3–0.7% transverse depending on gate position and wall thickness. This is lower and more anisotropic than unfilled PA12. Shrinkage anisotropy must be managed through gate location, packing pressure, and mould temperature, or warpage can exceed acceptable flatness tolerances in large flat electronic carrier trays and enclosure bases.

The electrical values in the table are indicative ranges for ESD-protected applications, not tightly controlled semiconductor-grade specifications. Actual surface and volume resistivity depend on mould temperature, shear history, fibre orientation, filler dispersion, moisture content, and post-mould storage. Moulders must establish lot-specific process capability because conductive filler distribution can vary with screw speed, back pressure, and gate geometry.

Pre-drying is a critical processing constraint. Polyamide 12 absorbs moisture more slowly than PA6 or PA66, but moisture levels above 0.10% can generate splay, surface silver streaks, and inconsistent ESD filler dispersion. A desiccant dryer set to 80 °C with a bed residence time of 4–6 h is typically sufficient from sealed packaging. Dew point should remain below -30 °C. If the resin has been exposed to ambient air at 60% relative humidity or higher, drying should extend to 6–8 h and be verified with a moisture analyser. Direct air dryers without desiccant cannot reliably reach the required dew point in tropical production environments.

Melt temperature during injection moulding is generally held between 230 °C and 270 °C. Lower melt temperatures reduce thermal degradation of the ESD filler system but increase viscosity and may hinder glass-fibre dispersion. Higher melt temperatures improve flow into thin sections but increase the risk of carbon-bearing filler degradation, brown streaks, and volatile emissions if residence time is excessive. The recommended mould temperature is between 40 °C and 80 °C. Lower mould temperatures shorten cycle time but can freeze the skin layer before the conductive filler network is adequately formed, increasing surface resistivity. Higher mould temperatures improve surface gloss, weld-line strength, and electrical consistency, but extend cycle time and increase post-mould shrinkage variation.

Production-scale equipment behaviour must account for screw design. A three-zone general-purpose screw with an L/D ratio of 18–22 and a compression ratio of 2.0–2.5 is suitable for this grade. The non-return valve should have a free-flow ring design to avoid dead spots where filled PA12 can degrade. Screw speed should be moderate, typically 80–150 rpm on a 25–40 mm screw diameter machine, depending on shot weight and residence time. Back pressure from 5 bar to 15 bar hydraulic is used to maintain a homogeneous glass and conductive filler dispersion without excessive shear. Shear-induced degradation of the conductive filler can occur if screw recovery time is too short or if the melt cushion is too large. The shot should use 50–80% of the barrel capacity to limit residence time below 10 min at full melt temperature. Regrind levels above 20% should be validated for electrical and mechanical property retention; glass-fibre breakage reduces modulus and impact performance while changing surface resistivity.

Electrical surface resistivity and charge decay under production conditions

The ESD function of Grilamid LV-23 ESD is evaluated primarily by surface resistivity according to IEC 62631-3-2 and volume resistivity according to IEC 62631-3-1. For ESD-protected areas under 100 V test voltage, the material typically occupies the dissipative range between 10⁶ Ω and 10⁹ Ω surface resistivity. This range is compatible with worksurface and handling-tray requirements in ANSI/ESD S20.20 and IEC 61340-5-1 where charge must be removed without the uncontrolled discharge associated with highly conductive materials below 10⁴ Ω. The glass fibre and ESD filler combine to provide a semiconductive path, but the path is not uniform through the cross-section. Weld lines, sharp corners, and flow-front hesitation can create electrically isolated regions even when the bulk moulding shows acceptable surface resistivity.

Charge-decay time is a more application-relevant measurement than surface resistivity alone. In a production setting, a moulded tray may show surface resistivity within specification but fail charge-decay testing because deep resistive layers delay charge movement. Testing should follow IEC 61340-2-3 for charge decay or ANSI/ESD STM11.11 for surface resistance. Measurement electrodes must be placed on the actual gate, weld-line, and end-of-fill regions, because dry PA12 GF23 ESD mouldings display anisotropic electrical properties. The gate area often has lower resistivity because fibre alignment and filler orientation create a more continuous conductive path, while weld lines and underpacked areas may show higher resistivity. This variability is a known production failure mode in ESD injection moulding and must be addressed through gate location and packing pressure rather than by increasing ESD filler content post hoc.

Humidity sensitivity of the electrical response is an operational boundary. Dry PA12 has lower moisture content, but once moulded parts are exposed to humid environments, the absorbed water acts as a polar species that can reduce surface resistivity in unfilled polyamides. In a carbon-filled ESD compound, the effect is not always monotonic; water uptake can swell the matrix and partially disrupt the conductive filler network, potentially increasing volume resistivity. Published data for this specific configuration is limited, so relative humidity below 30% or above 60% should be treated as a validation requirement rather than an assumed stable range.

In comparison with unfilled PA12 ESD grades, the 23% glass fibre in Grilamid LV-23 ESD reduces creep and increases rigidity, but it also creates a more anisotropic electrical response. In comparison with carbon-fibre-filled PA6 or PA66 ESD grades, the PA12 matrix provides lower moisture absorption and better dimensional stability in humid or wet environments. In comparison with stainless-steel-filled or carbon-black-filled ABS, the PA12 GF23 grade offers higher temperature resistance, better chemical resistance, and lower density than many stainless-steel-filled thermoplastics. However, it is less stiff than a high-modulus carbon-fibre-filled PA66 and may require thicker sections to match the stiffness of a metal-reinforced ESD compound.

When a PA12 ESD grade replaces PA6 ESD in electronics handling and fuel-system fixtures

Potential usage areas for Grilamid LV-23 ESD include injection-moulded ESD-safe transport trays, printed circuit board handling fixtures, assembly jigs, connector housings, and component carriers used in electronics manufacturing. The material is also suited to industrial environments where chemical exposure, low moisture, and dimensional stability are required. PA12 retains its mechanical properties better than PA6 or PA66 under humid conditions because its moisture absorption is lower. This makes it preferable for fixtures that are washed, exposed to glycol-based coolants, or used in uncontrolled storage areas.

The dry-state mechanical properties support thin-wall designs with lower mass than an equivalent PA66 ESD grade. However, the heat deflection temperature under 1.80 MPa is moderate, approximately 60 °C. Applications requiring continuous load at temperatures above 80 °C or short-term exposure above 100 °C should be confirmed against creep and deflection requirements. The PA12 matrix has good resistance to oils, greases, fuels, and many solvents, but strong acids, oxidising agents, and some chlorinated solvents may attack the polymer. Compatibility with production cleaning fluids should be tested according to ISO 22088-1 or ISO 175.

When comparing the ESD grade to standard Grilamid LV-23, the base mechanical and processing profile is similar, but the ESD filler changes viscosity, thermal stability, and electrical performance. Moulders report higher melt pressure at equivalent temperature because the conductive filler increases viscosity relative to an unfilled or glass-only PA12. Therefore, gate and runner sizing must account for the filler. Gate diameters should be at least 1.0 mm for parts with wall thickness near 2.0 mm and increased proportionally for thicker sections. Cold-runner systems should use full-round runners, and hot-runner manifolds must avoid dead spots where conductive filler can accumulate and carbonise. Hot-runner systems with external heating and no dead spots are preferred, but validation with the actual ESD filler is necessary because some conductive grades deposit conductive material on valve pins after extended runs.

The difference between dry and conditioned testing should be documented on the part drawing. Tensile and flexural data generated on dry-as-moulded specimens cannot be directly applied to parts stored in non-air-conditioned warehouses. Conversely, electrical data collected after prolonged humid storage may not represent performance in a dry nitrogen cabinet. Quality control should use sealed foil packaging after moulding if the ESD function is critical, because moisture uptake can shift surface resistance and dimensional characteristics.

Processing constraints at the limits of the window are more severe than for unfilled PA12. Barrel residence time above 10 min, melt temperature above 270 °C, or screw speed above 200 rpm on small screws can degrade the conductive filler and reduce tensile strength. Low mould temperature below 40 °C can produce a resin-rich skin that prevents the conductive network from reaching the surface, causing poor ESD performance despite acceptable mechanical properties. High mould temperature above 90 °C can improve surface conductivity but may require mould release or cause sticking in deep ribs. The use of mould-release sprays should be avoided because silicone-based release agents can insulate the surface and raise surface resistivity above the ESD limit.

For applications requiring compliance with REACH and RoHS, the grade should be verified against the manufacturer’s latest certification. This material class generally falls outside food-contact approval unless explicitly stated by the supplier. The ESD filler system, glass fibre content, and PA12 base polymer do not automatically confer FDA 21 CFR or EU 10/2011 compliance. Electrical and mechanical recycling of sprues and runners is possible, but the ESD performance must be revalidated for each regrind fraction because conductive filler distribution changes with repeated thermal and shear history.