| HS Code | 216542 |
| Density G Cm3 | 1.02 |
| Tensile Strength Mpa | 45 |
| Elongation At Break | 250 |
| Flexural Modulus Mpa | 1200 |
| Izod Impact Notched J M | 60 |
| Melting Point C | 178 |
| Heat Deflection Temperature At 0 45 Mpa C | 57 |
| Heat Deflection Temperature At 1 8 Mpa C | 40 |
| Water Absorption 24 Hr | 0.28 |
| Mold Shrinkage | 1.5 |
| Volume Resistivity Ohm Cm | 1.0E+12 |
| Dielectric Strength Kv Mm | 22 |
As an accredited Ashley Polymers Ashlene TD925H Nylon 12 factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Ashley Polymers Ashlene TD925H Nylon 12 is packaged as 25 kg net in sealed polyethylene-lined paper bags. |
| Container Loading (20′ FCL) | 20′ FCL loading of Ashley Polymers Ashlene TD925H Nylon 12 in palletized bags, secured for safe transport. |
| Shipping | Ashley Polymers Ashlene TD925H Nylon 12 ships as non-hazardous polymer pellets in sealed moisture-resistant bags or drums. Avoid excessive heat, open flames, and humidity. Keep containers dry and ventilated. Standard ground freight is suitable; no special hazmat designation applies for routine transportation. |
| Storage | Store Ashley Polymers Ashlene TD925H Nylon 12 in a cool, dry, well-ventilated area away from direct sunlight, heat sources, and moisture. Keep containers tightly sealed when not in use to prevent water absorption and contamination. Avoid creating dust; maintain good housekeeping. Follow manufacturer’s recommendations for shelf life and handling. |
| Shelf Life | Shelf life is typically two years if stored in original sealed containers in a cool, dry environment, avoiding moisture absorption. |
Extruded truck air brake tubing based on Ashley Polymers Ashlene TD925H Nylon 12 enters the line as pellets that must be dried at 80 °C for 4–6 h in a desiccant-bed dryer with a dew point below −40 °C; residual moisture is held below 0.10 wt% because hydrolysis at melt temperatures above 220 °C lowers melt strength and generates surface roughness in the sized tube wall. The melt is conveyed through a single-screw extruder of 30–45 mm diameter and L/D 24:1–30:1, using a barrier screw with compression ratio of 2.5:1–3.0:1, a screen pack of 60/80/60 mesh, and a temperature profile from 210 °C in the feed zone through 225 °C in the metering zone to 230 °C at the die head. For UV-stable black tube, 2–3 wt% carbon black masterbatch is added in a polyethylene carrier; heat-stabilizer masterbatch is added at 0.3–0.5 wt%. The parison is calibrated in a vacuum sizing tank at −0.25 bar to −0.45 bar with water at 15–25 °C, and pulled at 30–80 m/min depending on 6 mm to 16 mm outer diameter. Lot-to-lot melt-flow variation of ±2 g/10 min under ISO 1133-1:2022 shifts die-head pressure by 10–20 bar and requires puller-speed correction to hold wall concentricity. Final tube is coiled to 50 m or 100 m lengths and tested to SAE J844 and ISO 7628:2010 for burst pressure, cold impact at −40 °C, and zinc chloride stress-crack resistance. The terminal products are air brake coil assemblies, suspension leveling lines, and pneumatic pilot lines used in commercial vehicle chassis.
Multilayer fuel vapor tubing positions Ashlene TD925H Nylon 12 in the outer and inner layers of a five-layer structure that alternates polyamide, tie resin, and EVOH. In this architecture the polyamide layers are dried separately to below 0.10 wt% moisture while the EVOH barrier is dried to below 0.30 wt%; the tie resin is kept at room temperature but purged with the line. Five extruders feed a spiral mandrel die or a multi-manifold crosshead with individual melt pumps, each layer melt stream held within ±2 °C of its set point to preserve the viscosity ratio between the nylon 12 and EVOH; a typical layer ratio is 10:20:40:20:10 by wall thickness. The outer nylon 12 is formulated with 2–3 wt% carbon black for UV resistance, while the inner nylon 12 may use a conductive carbon black loading above 10 wt% to achieve surface resistivity below 10^6 Ω/sq for static dissipation if specified by the OEM. Process temperatures range from 230 °C to 245 °C; exceeding 255 °C risks EVOH degradation and gel formation at the tie-layer interface. After vacuum sizing at −0.30 bar, the tubing is tested for wall concentricity, burst pressure, and hydrocarbon permeation under SAE J2260 and SAE J1737 protocols. Terminal parts include fuel filler vent lines, canister purge lines, and onboard refueling vapor recovery lines.
| Matrix | Saturated moisture uptake at 23 °C | Dimensional change after 24 h water immersion | Test method |
|---|---|---|---|
| Nylon 12 | 1.4–1.5% | 0.2–0.3% | ISO 62:2008 |
| Nylon 6 | 9.0–9.5% | 1.5–2.0% | ISO 62:2008 |
| Nylon 66 | 8.0–8.5% | 1.4–1.8% | ISO 62:2008 |
Where unbonded flexible risers require a polymer pressure sheath in wet hydrocarbon service, Ashlene TD925H Nylon 12 is converted into thick-walled annulus sections over a metallic carcass on a purpose-built extrusion line. The process conflict is plasticizer retention: high-viscosity polyamide 12 grades used for flexible pipe liners often contain 6–12 wt% benzenesulfonamide plasticizer to maintain elongation at −30 °C, but barrel temperatures above 260 °C cause plasticizer volatilization and surface porosity. A grooved-feed single-screw extruder with 60–120 mm screw diameter and L/D 24:1–30:1 is operated at a flat temperature profile from 200 °C to 230 °C, feeding a coextrusion crosshead that deposits the sheath directly over the interlocked carcass at wall thicknesses of 3–10 mm. If TD925H is not plasticized, the lower barrel temperature of 220 °C to 235 °C may be used. Melt pressure at the die entrance is typically maintained between 80 bar and 140 bar; screw speed is adjusted to match line speed of 0.3–1.5 m/min for thick-wall coverage. The extrudate is cooled slowly with staged water mist and air to avoid shrink voids. Compliance is anchored to API Spec 17J and ISO 13628-2:2006, with qualification testing for resistance to methanol, CO₂, H₂S, and produced water at 90 °C. Published data for this specific configuration is limited; qualification programs should be run on each lot. Terminal assemblies are unbonded flexible riser sections, subsea flowline jumpers, and dynamic riser pressure sheaths.
On a high-speed optical fiber buffering line, Ashlene TD925H Nylon 12 is fed to a 20–25 mm single-screw extruder with L/D 24:1 and a screw compression ratio of 2.5:1; the melt temperature at the crosshead is maintained at 228 °C to 238 °C to balance viscosity against fiber tension. The fiber is preheated to 70–90 °C before entering the crosshead die so that the nylon 12 melt at 225–235 °C does not quench prematurely against the silica surface. A dual-layer pressure tool with die land length of 0.8–1.2 mm deposits a buffer coating of 0.20–0.25 mm radial thickness, producing a final diameter of 900 ± 25 µm. Laser micrometers at 50 Hz sampling and diameter-control loops adjust screw speed and capstan pull rate. The compound may be formulated with 2–4 wt% UV-stabilized color masterbatch, 0.2–0.4 wt% processing aid, and no filler to preserve low microbending; flame-retardant variants use 15–20 wt% halogen-free intumescent package only when plenum-rated. The line operates at 800–1,200 m/min; at speeds above 1,000 m/min, melt fracture and radial thickness variation become processing conflicts. Finished buffered fiber is tested per IEC 60794-1-2 and Telcordia GR-409 for strip force, heat aging, and attenuation change after temperature cycling. Terminal products are tight-buffered single-fiber cables, indoor distribution cable units, and pigtail assemblies.
Medical device extrusion of Ashlene TD925H Nylon 12 requires a documented resin biocompatibility file. If the grade is approved under ISO 10993-1:2018 or certified against USP <87> and USP <88> Class VI, it may be used unfilled or compounded with 20–40 wt% barium sulfate for radiopacity; tungsten loadings of 60–80 wt% are used for thin-wall shafts that must remain visible under fluoroscopy but these heavily filled compounds cannot be run on the same screw as unfilled resin. A 16 mm or 19 mm single-screw microextruder with L/D 20:1–24:1 and a barrier screw of 1.5:1–2.0:1 compression ratio is used. Barrel profile is kept low: 200 °C feed, 210 °C compression, 220 °C metering, 225 °C die. Melt pumps with 1.5–2.0 cm³/rev stabilize output for shaft outer diameters of 0.8–3.0 mm and wall thickness of 0.10–0.25 mm. The extrudate is cooled in a water trough at 10–20 °C and cut by a servo cutter; post-extrusion annealing at 80 °C for 4 h under nitrogen reduces residual stress before braiding. Adhesion to a stainless steel braid is achieved by plasma or corona treatment at 200–500 W·min/m² rather than adhesive primers. Terminal products are neurovascular catheter shafts, cardiovascular introducer sheaths, and delivery catheter bodies.
Direct injection molding of cable glands and strain-relief bodies from Ashlene TD925H Nylon 12 is carried out with dried pellet moisture below 0.10 wt%. The screw has L/D 20:1–24:1 and a nonreturn valve; barrel temperatures are 220 °C feed, 230 °C compression, 235 °C metering, and nozzle at 230 °C. Mold temperature is controlled at 40–80 °C to control post-mold shrinkage, and hold pressure of 50–80 MPa is applied until gate freeze. The clamp force is sized at 5–8 kN/cm² of projected area. The compound can be colored with 1–2 wt% masterbatch. The molded parts are tested for glow-wire ignition at 750 °C per IEC 60695-2-11, comparative tracking index per IEC 60112, and flame class per UL 94 as HB or V-2 depending on wall thickness. Terminal products are cable glands, threaded adapters, and photovoltaic junction box cable clamps.
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Ashley Polymers Ashlene TD925H Nylon 12 is a polyamide 12 extrusion compound in the Ashlene product line. The grade is specified for thin-wall tubing, pneumatic conduit, cable jacketing, and profile extrusion where low equilibrium moisture uptake, subzero ductility, and resistance to metallic salt solutions are required. For unfilled nylon 12 of this viscosity class, class-typical dry-as-molded tensile yield strength by ISO 527-2 is 40–50 MPa, elongation at break can exceed 200 %, flexural modulus by ISO 178 is commonly 1.2–1.6 GPa, density by ISO 1183-1 is 1.01–1.03 g/cm³, and the melting peak by ISO 11357-3 occurs near 175–180 °C. These values describe the polyamide 12 class rather than lot-specific TD925H data; the manufacturer’s certificate of analysis should be consulted for release parameters. The long methylene sequence between amide groups reduces hydrogen-bonded volume fraction compared with nylon 6 and nylon 66, lowering hygroscopic expansion and dry-as-molded modulus while improving low-temperature impact retention. The absence of uniform secondary datasheets for TD925H makes lot-specific melt volume-flow rate, stabilizer package, and impact data material to process design.
Moisture control is the primary processing constraint for Ashlene TD925H. Nylon 12 is hygroscopic, though less than nylon 6 or nylon 66; resin exposed to ambient air in opened gaylords can exceed 0.15 % moisture within 24 h in humid weather. Extrusion with moisture content above 0.10 % produces splay, surface roughness, and hydrolytic molecular weight loss in the metering zone. Desiccant drying is mandatory. Typical drying parameters for polyamide 12 extrusion grades are 80 °C for 4–6 h at a dew point of ≤ -30 °C. Return air dew point should remain at or below -20 °C. Hopper residence time above 8 h at temperature is not recommended for uninsulated hoppers, because prolonged hot dry air exposure can oxidize surface amide groups and shift melt viscosity.
On a single-screw extruder with L/D of 24:1–30:1, a typical barrel profile ranges from 200 °C at the feed throat to 220–240 °C in the compression zone and 230–250 °C at the metering section and die. Melt temperature measured at the die exit should be held between 225 °C and 250 °C. Residence time at melt temperature should not exceed 10–15 min. Above 270 °C, polyamide 12 degrades by chain scission with yellowing, moisture generation, and loss of melt strength. A melt pump between extruder and die is specified on production lines to reduce surging and permit lower screw speed, which limits shear heating. Compression ratios of 2.5:1–3.0:1 with a barrier section are common; high-shear mixing elements are unnecessary for unfilled nylon 12 and can create local melt temperature spikes.
Downstream, low draw ratios are used. The high melt viscosity of TD925H permits stable tube formation through a vacuum calibrator, but draw ratios above 1.15:1 introduce axial orientation that can increase longitudinal shrinkage during thermal cycling. A water cascade or vacuum tank held at 20–25 °C sets the outer wall rapidly; thicker sections crystallize more slowly from the inner wall, producing residual core stress. Annealing at 130–150 °C for 1–2 h after sizing is used on some tube lines to stabilize dimensions, but excessive spherulitic growth at the upper end of that range may reduce low-temperature impact.
In nylon 12, the polar amide group is separated by 11 methylene units, compared with 5 methylene units in nylon 6 and alternating 4- and 6-carbon segments in nylon 66. The lower amide density reduces water absorption. The practical consequence for TD925H tubing is that the shift from dry-as-molded to 50 % RH equilibrium produces a smaller dimensional increase and a less severe modulus drop than equivalent nylon 6 or nylon 66 components. However, the change is not zero. Tubes extruded at 0.10 % moisture may expand by approximately 0.2–0.4 % in wall thickness when moved to 50 % RH, depending on crystallinity, draw ratio, and wall thickness. Absorbed water acts as a plasticizer, lowering the glass transition and increasing notched impact resistance at low temperatures. Comparative dimensional stability measurements require accelerated conditioning per ISO 1110 or the buyer’s conditioning protocol, not uncontrolled ambient storage.
Chemical resistance limits define a separate operational boundary. The long alkane segment in nylon 12 confers tolerance to dilute aqueous salt solutions and many aliphatic hydrocarbons, but strong acids, phenols, formic acid, and oxidizing media degrade the polymer. Zinc chloride solutions, which rapidly stress-crack nylon 6 and nylon 66, are tolerated by nylon 12 to a greater degree, making the grade suitable for automotive tubing exposed to road de-icing salts. Continuous exposure to saturated zinc chloride at elevated temperature is not recommended without lot-specific stress-crack testing, because plasticizer migration and residual extrusion stress control time to failure. The grade should not be combined with amine-based additives or certain phenolic antioxidant concentrates without compatibility testing; published data for TD925H in amine-containing masterbatches is limited.
Polyamide 12 is selected for air-brake tubing because the performance envelope under SAE J844 or ISO 7628 includes cold impact, burst-pressure retention, and resistance to road-salt-derived chloride stress cracking. In these applications, failure modes are dominated by environmental stress cracking rather than simple tensile overload. The critical processing variable is frozen-in orientation from extrusion. High draw ratios and rapid quenching align the amorphous tie chains in the axial direction, reducing hoop-direction environmental stress-crack resistance. TD925H should therefore be extruded with controlled draw and, where wall thickness permits, annealed or conditioned to reduce molded-in stress. Published numerical thresholds for residual stress in TD925H are limited, but lot-specific stress-crack testing in 50 % zinc chloride solution at 23 °C is commonly used as a release gate for automotive tube producers.
| Property | Test method | Nylon 12 | Nylon 6 | Nylon 66 |
|---|---|---|---|---|
| Density | ISO 1183-1 | 1.01–1.03 g/cm³ | 1.12–1.14 g/cm³ | 1.13–1.15 g/cm³ |
| Melting peak | ISO 11357-3 | 175–180 °C | 220–225 °C | 255–265 °C |
| Equilibrium moisture at 23 °C, 50 % RH | ISO 62 | 0.7–0.9 % | 2.5–3.0 % | 2.2–2.8 % |
| Tensile modulus, dry | ISO 527-2 | 1.4–1.8 GPa | 2.8–3.5 GPa | 3.0–3.5 GPa |
The table represents class-typical values rather than TD925H lot-specific data. The product’s differentiation within the Ashlene line is primarily rheological: the TD925H designation identifies an extrusion-grade nylon 12 with higher melt viscosity than injection-molding grades. This higher viscosity maintains a wider processing window for thin-wall tube extrusion but generates higher die pressure and lower spiral-flow length in injection molding. Processors converting the material in injection molding should evaluate flow-path-to-wall-thickness ratios and venting before specifying the grade.
When TD925H is considered as a replacement for nylon 6 or nylon 66 in pneumatic tubing, cable jackets, or fuel-vapor lines, the trade-offs are systematic rather than universally superior. Dry-as-molded tensile strength of unfilled nylon 12 is lower than that of nylon 6 or nylon 66, and heat deflection temperature under load is reduced because the melting point is 175–180 °C versus 220–225 °C for nylon 6 and 255–265 °C for nylon 66. Continuous load-bearing temperature is therefore lower; unfilled nylon 12 heat deflection temperature by ISO 75-2 at 1.8 MPa is often below 60 °C. The return is lower moisture absorption, lower density, better retention of impact at subzero temperatures, and improved resistance to chloride-induced stress cracking. In automotive air-brake tubing, the critical selection criterion is often the combination of burst-pressure retention at -40 °C, cold impact, and chloride stress-crack resistance, not room-temperature tensile strength.
Compared with polyamide 11, nylon 12 has a marginally longer methylene sequence. The practical result is a slightly lower melting point and lower equilibrium moisture uptake, but the two are often interchanged in low-temperature tubing. Solvent resistance, flexural fatigue, and plasticizer retention can differ by formulation and molecular weight, so TD925H should not be treated as a direct drop-in for a polyamide 11 grade without comparative testing against the specific application fluid and temperature cycle. Published product-specific data for TD925H in direct comparison with polyamide 11 is limited.
Where UV resistance is required, a carbon black concentrate is added at 2–3 wt%; unfilled natural nylon 12 is not rated for prolonged outdoor exposure. The grade is normally supplied in black for automotive tubing. Regrind from post-industrial tube scrap is used at levels up to 20 % with virgin material on some production lines, provided the regrind is dried, screened for fines, and limited to one or two heat histories. Multiple heat histories shift melt viscosity and increase the probability of gel formation in thin-wall extrusion.
Specifications for lot acceptance should include melt volume-flow rate by ISO 1133-1, density by ISO 1183-1, tensile properties by ISO 527-2, flexural properties by ISO 178, Charpy impact by ISO 179-1/1eA, water absorption by ISO 62, and melting peak by ISO 11357-3. Food-contact or medical-use compliance must be confirmed against 21 CFR 177.1500 or USP Class VI for the specific lot; such status cannot be assumed from the base polyamide 12 chemistry. The grade is not recommended for service in concentrated strong acids, phenols, or oxidizing environments, and continuous exposure to hot aqueous salt solutions above ambient temperature should be validated by the end user because stress-crack resistance is highly dependent on molded-in orientation and plasticizer content.
