Aurora Kunststoffe AUROmid PA12 TR90 black 9005 PA12, Dry is a black-pigmented amorphous polyamide 12 compound supplied in a moisture-controlled dry condition. The TR90 designation identifies a transparent polyamide architecture based on PA12 chemistry. The black 9005 designation corresponds to RAL 9005 jet black. The dry condition means that the granulate is conditioned to a residual moisture level suitable for direct processing, but it is not permanently dry; polyamide 12 is hygroscopic and will regain moisture after the original packaging is opened. This grade is differentiated from standard semicrystalline PA12 by the absence of a sharp crystalline melting point, more isotropic shrinkage, and a property profile intended for thin-wall moulded components. Because black coloration may be achieved with organic dye or carbon black, applications requiring defined surface resistivity, laser-weld compatibility, or food-contact status must confirm the pigment package with Aurora Kunststoffe before release.

What Are the Processing Boundaries for the Dry Black 9005 Grade?

Moisture control remains the primary processing boundary. The dry condition is referenced to a residual moisture content below 0.10 wt%; verification should be performed by ISO 15512 Karl Fischer titration or an equivalent moisture-specific method. Once the packaging is opened at ambient relative humidity above 60 %RH, the granulate should be re-dried in a dehumidifying dryer at 80 °C for 4 h to 6 h. The drying air must have a dew point below -30 °C. Drying above 100 °C or extended residence in a hopper dryer at high temperature can cause oxidative discoloration of the black compound and should be avoided.

For compounding and moulding, a screw with L/D ratio between 20:1 and 25:1 and a compression ratio of 2:1 to 2.5:1 is adequate for injection moulding. Barrel profiles from feed to nozzle in the range 240 °C to 290 °C are typical, with a melt temperature between 270 °C and 285 °C. Mould temperatures of 60 °C to 90 °C support surface replication and reduce internal stress. In thin-wall sections below 1.2 mm, higher melt temperature helps filling but narrows the residence-time window. Injection pressure in the range 80 MPa to 120 MPa and holding pressure of 60 MPa to 80 MPa are typical starting points, but actual cavity pressure should be measured and used for process control.

Residence time should be limited to 8 min to 12 min at melt temperatures above 280 °C. Longer thermal exposure reduces notched impact strength and can produce black speck formation when the pigment system degrades. Purging with a polyolefin before and after the campaign reduces cross-contamination in colour-sensitive production. On twin-screw compounding equipment with L/D ratios near 40:1, melt temperature should remain below 300 °C to avoid thermal-oxidative chain scission. When carbon black masterbatch is used, dispersion quality should be checked by pressure filter test or film surface inspection; poor dispersion appears as black specks in moulded parts. Colour consistency under RAL 9005 is typically verified by spectrophotometric measurement according to ISO 11664-4 or DIN 5033-4.

Design verification data for this product family are generated according to ISO 10350-1 specimen preparation and conditioning procedures. Table 1 summarizes published databook ranges for comparable PA12 TR90 black compounds; the ranges are reference values, not lot-specific specifications. Because pigment type and dry-state moisture can shift tensile elongation and Charpy impact by 10 % to 20 %, batch-specific values should be obtained from the Aurora Kunststoffe certificate of analysis before tooling is finalized.

For rheological characterisation, the melt volume rate of similar amorphous PA12 TR90 grades measured at 275 °C under 5 kg load according to ISO 1133-1:2022 is typically reported between 10 cm³/10 min and 20 cm³/10 min. The melt is shear-thinning; injection rates should be high enough to avoid premature freeze-off in thin rims, but excessive injection speed can generate shear heating above 300 °C at the gate. Published data for this specific configuration is limited, so process feasibility should be validated with a short-shot study and cavity pressure sensors.

Table 2 places the material against two alternative materials. The data are taken from published thermoplastic databooks and are provided only to show relative differences; final material selection requires testing of the actual moulded article under the applicable end-use standard.

When Black 9005 Pigmentation Replaces Natural Transparency

Natural TR90 offers high visible-light transmission. The RAL 9005 black pigmentation eliminates that transmission and may be achieved with soluble dyes or carbon black. In amorphous PA12 TR90, soluble black dyes generally leave the matrix amorphous and do not reduce surface resistivity below 10^12 Ω when measured according to IEC 62631-3-2 or ASTM D257. Carbon black at concentrations above the percolation threshold can lower surface resistivity to 10^3–10^6 Ω and can also raise melt viscosity due to increased filler content. Published data for this specific configuration is limited; therefore, static-dissipative or electrically insulated components must be validated on production parts.

Black pigmentation also affects marking and joining. On RAL 9005 substrates, dark laser marking typically yields low contrast; white or high-brightness marking is preferably achieved with nanosecond or picosecond lasers and verified against ISO 24016 or internal contrast standards. In laser transmission welding, black 9005 may be used as the absorbing layer against a natural PA12 TR90 transmitting layer, provided the black pigment is selected for near-infrared absorption and the weld process is qualified by lap shear testing and tensile testing per ISO 527-1/-2 on welded specimens. If the black pigment is carbon black, UV lightfastness is generally high when evaluated according to ISO 4892-2; if an organic dye is used, colour stability must be verified.

Regulatory Evidence and Conditioning Documentation

The dried product should be supported by a certificate of analysis containing residual moisture content, colour value, lot number, and melt flow data. Compliance with RoHS Directive 2011/65/EU Annex II restricted substances and REACH Regulation (EC) No 1907/2006 Article 33 SVHC notification must be confirmed against the current supplier declaration for the specific black 9005 grade. The polymer base PA12 TR90 may be assessed under FDA 21 CFR 177.1500 for nylon resins, but the dry condition does not automatically confer food-contact or medical status. Medical-grade applications require separate biocompatibility assessment according to ISO 10993-1 and validation of black pigment extractables.

For automotive or electrical components, short-term temperature resistance should be checked against the end-use standard rather than generic Vicat or HDT values. The material should not be exposed continuously above 90 °C under load without creep testing according to ISO 899-1. Incompatibility with strong acids, oxidizing agents, and polar solvents should be evaluated because the amide linkage is susceptible to hydrolysis under acidic conditions at elevated temperature.

In eyewear frame production, the combination of 0.99–1.01 g/cm³ density and 1400–1700 MPa tensile modulus supports lightweight frames with recovery after bending. Moulding trials on electric injection machines with clamp forces above 500 kN for multi-cavity frame tools have shown that dried granulate reduces gas burn, silver streaks, and dimensional drift in hinge areas. The processing window is narrow in thin-wall cross-sections below 1.2 mm; melt temperature must be kept above 270 °C to fill the rims, but residence time must be below 10 min to avoid thermal degradation. Black RAL 9005 colour hides minor discoloration but does not eliminate mechanical loss caused by hydrolysis if the material is re-dried incorrectly. Final frames should be evaluated under ISO 12870 for spectacle frame durability, including dimensional stability and resistance to perspiration.

In sports protective equipment and medical device housings, the amorphous PA12 TR90 grade offers higher chemical resistance than polycarbonate to skin oils and common disinfectants. However, the dry condition alone does not guarantee low post-mould moisture uptake. Parts should be conditioned in sealed pouches if dimensional tolerances below ±0.05 mm are required because PA12 TR90 absorbs moisture and undergoes slight expansion and ductility changes. Published data for this specific configuration is limited for repeated autoclave sterilisation; steam sterilisation should be validated on the finished component because black pigment and processing aids may migrate or alter surface properties.

Compared with standard semicrystalline PA12, the TR90 black dry variant provides more isotropic shrinkage, lower warpage, and more consistent impact behaviour across weld lines in complex moulded frames. Compared with polycarbonate, it generally exhibits better resistance to stress cracking in contact with oils and lower density, but lower modulus and higher moisture uptake. The final choice is governed by the required ISO 527-1/-2 tensile modulus, ISO 179-1/1eA impact, and the applicable product standard such as ISO 12870 for spectacle frames or ISO 16321-1 for occupational eye and face protection.