EMS-Grivory Grilamid TRVX-50X9 black 9230 Nylon 12, 50% Glass Fiber Reinforced, Dry is a semi-crystalline polyamide 12 injection-moulding compound containing 50% by mass glass-fibre reinforcement. The “Dry” term in the product description refers to the conditioning state of the test specimens used for the published mechanical data, not to a moisture level guaranteed in the as-supplied granulate. Under ISO 1110, dry-as-moulded polyamide test pieces are brought to a moisture content below 0.1% by weight before tensile, flexural, and impact testing. This is distinct from the conditioned state, in which specimens are stored at 23°C and 50% relative humidity until equilibrium. The black 9230 colour code is a carbon-black pigment formulation that provides uniform part colour and limited ultraviolet screening in light-exposed applications. The compound is supplied as cylindrical granules and can be processed on conventional single-screw machinery or screw-injection moulding machines. Under ISO 1043, the abbreviated designation is PA12-GF50, indicating a polyamide 12 matrix with 50% glass fibre. The volume fraction of glass is lower than the mass fraction because the density of the glass reinforcement is approximately 2.54 g/cm³ and the density of unfilled PA12 is approximately 1.01–1.03 g/cm³; the volumetric glass-fibre content is therefore around 28–30%, which affects flow-front behaviour, weld-line morphology, and shrinkage anisotropy.

Compared with PA6-GF50 or PA66-GF50 at equivalent glass loading, the PA12 base resin changes the moisture response and part mass. Unfilled PA12 normally absorbs about 1.5% water at saturation, while unfilled PA66 absorbs approximately 8–9% under comparable ISO 62 immersion conditions. In the reinforced compound this absolute difference is lower but remains functionally important: the TRVX-50X9 grade retains a relatively high fraction of its dry-as-moulded stiffness after moisture conditioning because fewer amide groups are available for hydrogen bonding with water. The density of TRVX-50X9 is reported near 1.29 g/cm³ by ISO 1183, whereas typical PA66-GF50 compounds are in the range 1.55–1.58 g/cm³. This density gap of approximately 0.27 g/cm³ can reduce part mass by roughly 17% for the same volume, provided that wall-section stiffness, strength, and thermal requirements permit a direct substitution.

How Does the PA12 Backbone Change the Performance of a 50% Glass-Fibre Compound?

The high fibre fraction dominates the tensile behaviour. Published datasheet values for TRVX-50X9 black 9230 in the dry state place tensile modulus near 11000 MPa according to ISO 527-1/-2, tensile strength at break near 140 MPa, and elongation at break around 3%. The conditioned tensile modulus is lower but remains above 9000 MPa in typical datasets. This behaviour differs from unfilled PA12, which may show tensile modulus below 1500 MPa and elongation at break above 50%. The glass reinforcement suppresses ductile yielding and converts the deformation mode to fibre-dominated load transfer. Notched Charpy impact strength at 23°C is typically reported near 12 kJ/m² using ISO 179/1eA, and the value at −30°C decreases to roughly 8 kJ/m². The material therefore provides useful low-temperature toughness for an aliphatic polyamide, but the high fibre content makes its impact response more brittle than unreinforced or impact-modified PA12 grades. Designers should not use the 23°C dry value alone for snap-fit or press-fit geometries.

Thermal properties reflect the PA12 crystalline phase. Melting temperature is reported near 178°C by ISO 11357. Heat deflection temperature under 1.80 MPa, measured by ISO 75, is approximately 165°C, while Vicat softening temperature is near 180°C under ISO 306. These values are lower than those of semi-aromatic PPA GF50 or PPS GF50 grades, which may exceed 200°C in HDT/A. The PA12 compound therefore should not be specified as a direct replacement for PPS or PPA in under-hood components where sustained temperatures exceed 150°C in air. However, for many compressed-air fittings, fuel clips, and hydraulic-system connectors operating in the −20°C to 80°C range, the heat resistance of TRVX-50X9 is adequate and its lower melt temperature allows filling of thin sections at lower barrel settings. The high fibre fraction also reduces linear mould shrinkage. Typical shrinkage values measured on 60 mm × 60 mm × 2 mm plaques according to ISO 294-4 fall in the 0.1%–0.4% range, with lower shrinkage parallel to flow than normal to flow because of fibre orientation.

The following table consolidates the dry-as-moulded property envelope generally reported for this grade. The values are typical and should not be read as guaranteed specification limits. For final part design, the manufacturer’s current raw-material specification and the results from on-site moulding trials must be used.

Design use of the dry tensile modulus near 11000 MPa should include a reduction factor where the part will operate at elevated humidity or submerged water conditions. The dry-state modulus is the appropriate input only for short-term loading in low-moisture environments. Conditioned values, generated after accelerated moisture exposure, should be used for long-term dimensional and structural calculations involving atmospheric humidity.

If the Melt Stream Reaches a Multi-Cavity Tool Through a Hot Runner at 260°C

Melt-processing conditions for this grade are bounded by the hydrolysis sensitivity of the PA12 matrix and the fibre-length degradation caused by excessive shear. The granulate requires pre-drying before injection moulding or extrusion. Drying in a desiccant-bed dryer with a dew point of −30°C or lower at 80°C for 4–8 h is recommended to bring the moisture content below 0.1%. If the drying hopper is open to ambient air, hold-up time should be limited to prevent re-absorption; dry-air conveying and hopper blanketing are preferred in production lines operating above 60% relative humidity. Melt temperature measured at the nozzle should be controlled between 250°C and 280°C. Temperatures above 290°C increase the risk of oxidative yellowing and molecular-weight reduction, while temperatures below 240°C can lead to high melt viscosity, poor fibre wet-out, and short shots in thin sections. Tool surface temperature should be held between 60°C and 100°C. A tool temperature at the lower end of this range reduces cycle time but may produce dull surface finish and lower crystallinity; a tool temperature near 100°C improves weld-line strength, reduces post-mould warpage, and stabilizes as-moulded dimensions but increases cooling time.

Screw geometry for reciprocating-screw injection moulding should use a general-purpose thermoplastic polyamide screw with a compression ratio in the range 2:1–3:1 and an L/D ratio of 20:1–25:1. The check-ring assembly should have adequate wear resistance because the glass fibre is abrasive. Back pressure is typically kept between 2 MPa and 6 MPa to homogenize the melt without excessive fibre attrition. Injection speed should be set to produce a stable flow front without jetting; for thin-wall connectors with wall thickness below 1.5 mm, high injection velocities may be necessary, but this raises shear heating and can reduce the effective melt viscosity. Regrind from sprues and runners may be re-used up to 30% by weight only after confirming that notched impact and tensile properties remain within the part specification. Fibre-length reduction during regrinding is the dominant risk: each granulation pass shortens the glass fibres and shifts the fibre-length distribution toward shorter length classes, which reduces notched impact and fatigue performance. On twin-screw compounding lines, this effect is controlled by feeding glass fibre downstream of the polymer melting zone rather than in the main feed, but on injection moulding shops the same control is not available.

For hot-runner systems, the temperature must be profiled so that the melt does not stagnate in the manifold. Dead spots, sharp channel bends, and undersized gates are critical because resin residence time in a hot runner at 260°C beyond approximately 10 min can promote thermal degradation. Hot-runner tips should be sized for the reinforced compound; glass fibre can erode conventional tip materials, and valve-gate designs should be evaluated for fibre breakage at the gate. Weld lines in multi-cavity fluid connectors are unavoidable when flow fronts recombine around cores. The dry-state weld-line tensile strength of a 50% glass-fibre PA12 is lower than the bulk tensile strength; weld-line specimens tested under ISO 527-1/-2 should be generated from the production tool rather than from an ISO multipurpose tensile bar because the local fibre orientation at the weld line determines practical part strength.

Typical application fields in technical literature for 50% glass-filled PA12 compounds include compressed-air fittings, fluid-system quick connectors, fuel-line clips, pneumatic valve bodies, pump housings, and structural brackets exposed to hydrocarbons or lubricants. The PA12 matrix offers resistance to many aliphatic hydrocarbons, oils, greases, and automotive fuels; however, it can be attacked by concentrated mineral acids, phenolic solvents, and certain organic acids at elevated temperature. Long-term chemical exposure data for this specific configuration are limited, so trials should be conducted under ISO 22088 or ASTM D543 using the actual service fluid, temperature, and external stress. Hot-water exposure above 60°C is a known boundary for polyamide 12: hydrolysis of the amide bond accelerates with temperature, and parts requiring continuous hot-water or steam service should be assessed against a hydrolysis-resistant grade or a different polymer family.

Regulatory declarations for this product should be obtained from the manufacturer’s product-stewardship documentation. The black 9230 colour package is normally part of the standard commercial range, and the grade may be reported as compliant with RoHS Directive 2011/65/EU and REACH Regulation 1907/2006 for the stated colour and glass-fibre formulation. Food-contact suitability should be verified against the specific end-use article; a general material datasheet compliance statement is not a substitute for migration testing under the applicable food-contact regulation. Flammability classification is typically UL 94 HB for a glass-filled aliphatic polyamide; the actual classification depends on thickness and colour, so the current UL yellow-card listing must be checked for the black 9230 variant.