| HS Code | 625690 |
| Material | Polyamide 11 (PA11) |
| Color | Grey |
| Density | 1.04 g/cm³ |
| Melting Point | 186 °C |
| Particle Size D50 | 30 µm |
| Water Absorption 24h | 1.0% |
| Tensile Strength | 40 MPa |
| Elongation At Break | 200% |
| Shore Hardness | D 75 |
| Impact Strength Charpy | 60 kJ/m² |
| Dielectric Strength | 16 kV/mm |
| Abrasion Resistance | Excellent |
As an accredited Arkema Rilsan Fine Powders T GREY 7310 AC PA11 factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Supplied in 25 kg multi-layer paper bags with inner liner: Arkema Rilsan T Grey 7310 AC PA11 fine grey powder. |
| Container Loading (20′ FCL) | Load 20' FCL with palletized bags of Arkema Rilsan Fine Powders T GREY 7310 AC PA11, securing cargo to prevent shifting and protect from moisture. |
| Shipping | Ship as non-hazardous fine powder in sealed moisture-proof bags or drums, palletized and labeled. Avoid dust generation and ignition sources; store dry and cool. Ensure proper grounding during handling. No special transport classification required, but secure to prevent bag damage and contamination. |
| Storage | Store Arkema Rilsan Fine Powders T GREY 7310 AC PA11 in its original, tightly sealed container in a cool, dry, well-ventilated area. Keep away from heat, open flames, sparks, and direct sunlight. Protect from moisture and humidity to prevent agglomeration. Avoid creating dust clouds; keep containers closed when not in use. |
| Shelf Life | Shelf life is two years from manufacture if stored unopened in original packaging in a cool, dry place. |
Arkema Rilsan Fine Powders T GREY 7310 AC PA11 is a pigmented polyamide 11 fine powder supplied for fluidised-bed and electrostatic spray coating of metal substrates. The melt peak is normally observed between 184°C and 188°C by ASTM D3418 at a scan rate of 10°C/min. Powder particle size distribution should be measured according to ISO 8130-2:2021 before line start because transfer efficiency in a fluidised bed changes when the fraction below 40 µm increases. In dishwasher basket coating, low-carbon steel wire is degreased in an alkaline bath, rinsed, and dried. The wire is then grit-blasted to cleanliness grade Sa 2.5 as defined by ISO 8501-1. The part is preheated in a forced-air convection oven with chamber uniformity of ±5°C until the surface reaches 280–330°C for heavy wire frames. The heated rack is immersed in a fluidised bed for 3–6 s. The deposited mass flows and levels during post-cure at 180–200°C for 5–10 min. Resulting film thickness ranges from 300 µm to 450 µm on the main wire surface. Edge thickness on wire ends can fall below 150 µm if swirl plate air pressure is below 0.2 bar. Dishwasher detergents at 65–75°C expose the coating to alkaline salts, oxygen bleaches, and rinse-aid surfactants. PA11 hydrolytic stability is sufficient for repeated domestic cycles, but the pigmented grey surface should be checked for gloss retention under ISO 2813 after 1,000 h immersion in a phosphate-based detergent solution at 70°C. The product does not require a liquid primer on blast-cleaned steel, which eliminates one solvent source from the coating line. Adhesion is verified on a separate coupon with cross-cut tape per ISO 2409; a class of 0 or 1 is normally required. The end-use article is a dishwasher basket, freezer shelving, or laundry appliance rack that must survive 2,000–5,000 wash cycles without red rust on the wire intersections. Published data for the exact grey pigmented grade under all detergent formulations is limited; qualification should include the customer’s specific detergent blend.
Rework of coated dishwasher baskets is limited. If film thickness is below 250 µm at the wire intersection, the basket is often re-preheated and dipped a second time. A second dip can raise total thickness above 600 µm and create stress cracking at welded nodes. Blast-cleaned wire should therefore be checked for roughness using ISO 8503-2; a profile of 50–75 µm is typical for PA11 powder adhesion. Powder reclaimed from the fluidised bed should be sieved to 200 µm to remove fused agglomerates. Moisture uptake above 0.1% in stored powder causes sintered lumps in the bed and poor fluidisation. If the bed air relative humidity exceeds 60%, the powder should be pre-dried according to the supplier’s procedure before the next production run.
The table below identifies the standards used to verify coating quality on production parts. Acceptance values are fixed per part drawing and substrate; the matrix only lists the method and the industrial trigger for each test.
| Standard reference | Purpose | Where applied |
|---|---|---|
| ISO 8501-1 | Visual cleanliness of abrasive blast-cleaned steel | All steel and cast iron before preheat |
| ISO 8130-2:2021 | Laser diffraction particle size distribution for coating powders | Incoming powder control |
| ISO 2409 | Cross-cut adhesion classification | Finished part coupon |
| ISO 9227 | Neutral salt spray exposure | Anti-corrosion qualification |
| ASTM D4060 | Taber abrasion resistance | High-wear furniture and appliance parts |
| ASTM D149 | Dielectric strength of insulating films | Electrical busbar insulation |
| ISO 2812-1 | Resistance to liquids by immersion | Chemical and disinfection exposure |
| NSF/ANSI 61 | Certification of potable water contact materials | Valves and fittings |
| RoHS Directive 2011/65/EU | Restricted heavy metal content in homogeneous coating | Electrical and electronic equipment |
When ductile iron gate valves are coated with grey 7310 AC, foundry scale is removed by abrasive blasting to Sa 2.5 in accordance with ISO 8501-1. Cast iron parts are often preheated slowly to 280°C over 20–30 min to drive off absorbed moisture and avoid pinholes from graphite nodule outgassing. The valve body is then dipped in a fluidised bed. Immersion time of 4–8 s produces a film of 350–500 µm on the body exterior. Post-cure is performed at 180–190°C for 8–12 min or until the part surface reaches 185°C. The absence of solvent in the powder process eliminates VOC emissions during application, but masking of flanges and threads must be completed before preheat. Potable water valves require material certification. PA11 coatings have been accepted under NSF/ANSI 61 and WRAS for some suppliers, but the current certification status of grey 7310 AC must be verified with Arkema or the holder of the certification. Free chlorine at municipal residual levels of 0.2–4.0 mg/L does not produce rapid oxidative attack on PA11. Resistance to chlorinated water is evaluated by immersion in 5 ppm free chlorine at 23°C for 1,000 h according to ISO 2812-1, although each water utility may impose its own tensile adhesion requirements. The finished product is a gate valve, butterfly valve disc, or pump casing that must not leach organic compounds above drinking-water limits. Impact damage on valve flange edges is checked with ISO 6272-1 at 2.5 J; failure at lower energy indicates underbaking or inadequate surface profile. The powder should not be applied over solvent-borne primed flanges unless the primer has been qualified for 180°C bake cycles.
In automotive seat spring coating, edge coverage is the primary process gate. The grey 7310 AC powder is sprayed electrostatically with a corona charging gun at 60–80 kV. The spring is suspended on a rotating jig to allow the powder to reach the coil pockets. Gun-to-part distance is held between 150 mm and 250 mm. Film thickness on the outer coil surface is maintained at 180–250 µm. The inner coil radius can retain 80–120 µm if the coil spacing is below 10 mm. A tribo gun may be used instead of corona if deep Faraday-cage areas show insufficient powder penetration. After spraying, the coated spring is cured in a convection oven at 190–200°C for 12–18 min metal temperature. Cure is confirmed by solvent resistance or DSC; an underbaked PA11 coating retains residual crystallinity at the interface and loses impact performance. Seat spring coatings are qualified by stone-chip resistance according to ISO 20567-1 using chilled cast-iron shot at 2 bar, followed by ISO 2409 adhesion. Thermal cycling from −40°C to 85°C over 100 cycles is common for passenger car interior parts; coating cracks on the compression side of the spring are cause for rejection. Continuous service above 120°C is not recommended for unreinforced PA11 powder coatings because oxidative embrittlement occurs. The end product is a seat spring, brake pedal bracket, or boot lid counterbalance spring with a grey protective layer that replaces a zinc-rich paint system.
The process ranges below are starting values for a new coating line. Part mass, oven load density, and air-distribution plate condition require local adjustment.
| Substrate | Preheat range | Film thickness | Post-cure |
|---|---|---|---|
| Low-carbon steel wire | 280–330°C | 300–450 µm | 180–200°C for 5–10 min |
| Ductile iron castings | 280°C after slow ramp | 350–500 µm | 180–190°C for 8–12 min |
| Zinc-galvanised steel | 260–290°C | 200–350 µm | 180–190°C for 6–10 min |
| Copper busbar stock | 250–300°C | 300–450 µm flat; 120–180 µm sharp edge | 180–190°C for 8–12 min |
Copper busbar insulation demands film continuity on radii below 0.5 mm. Sharp edges produce localised dielectric thinning during powder flow. Busbars are cleaned to remove cupric oxide with a mild acid etch, rinsed, and preheated to 250–300°C in a convection oven. A single fluidised-bed dip builds a film of 300–450 µm on flat faces. The same dip can leave 120–180 µm on a 0.3 mm edge radius. A second dip or pre-coating the edges by electrostatic spray is required when the design withstand voltage is above 2 kV. Dielectric strength is measured with ASTM D149 using opposed cylindrical electrodes in insulating oil at 23°C. Reported values for unfilled PA11 films are commonly in the range 15–25 kV/mm under dry conditions. The pigmented grey grade may show small differences due to inorganic colourants; the exact value should be measured on production-coated coupons. Film thickness below 250 µm on the busbar lower corner should be treated as a reject if the part is used in switchgear exposed to overvoltage transients. The powder provides electrical insulation without the use of halogenated flame retardants; however, the material is not a UL 94 V-0 system. The flammability classification of grey 7310 AC should be confirmed under the relevant end-product standard. The coated busbar is used in low-voltage switchgear, battery disconnect units, and industrial power distribution blocks. Thermal cycling from −40°C to 125°C can produce microcracks if the total film thickness exceeds 500 µm because of the thermal expansion mismatch between copper and PA11. Coated copper parts should be radiused above 1.0 mm where possible; burrs are removed according to ISO 13715 before coating.
Hospital bed frames made from 25 mm round steel tube are coated without a liquid primer after abrasive cleaning. The substrate is preheated to 270–300°C and dipped for 4–8 s in a fluidised bed. Post-cure at 180–190°C for 8–12 min produces a smooth grey film of 300–400 µm. The coating withstands repeated cleaning with quaternary ammonium disinfectants, dilute sodium hypochlorite at 0.1%, and 70% isopropanol. Spot testing under ISO 2812-1 for 24 h at 23°C is used to establish compatibility. Avoid concentrated phenol, formic acid, and strong oxidising acids because PA11 softens or hydrolyses in these media. The grey 7310 AC grade does not contain registered antimicrobial additives. Disinfection efficacy remains the responsibility of the furniture manufacturer and is a function of surface smoothness and cleaning protocol. Impact resistance is verified with ISO 6272-1 at 2 J to simulate wheelchair strikes. Adhesion after repeated thermal disinfection at 80°C should be tested using ISO 2409 every 1,000 cycles. The end product is an overbed table frame, bed rail, treatment trolley, or diagnostic equipment cart. The grey coating replaces liquid epoxy-polyester systems and provides a non-porous surface that resists iodine-based skin disinfectants. Sharp tube ends are deburred and radiused to 1.0 mm before coating to prevent thin edge film formation. Published data for the specific grey 7310 AC under high-level disinfectant immersion is limited; a qualification coupon should be run with each cleaning agent used in the hospital.
Galvanised architectural steelwork presents two process conflicts. The zinc layer begins to degrade compositionally above 200°C if the part is held too long, while PA11 requires a sufficiently high substrate temperature to flow and build film. The steel is sweep-blasted with fine Al₂O₃ grit at 2–3 bar to remove zinc oxide without removing the full galvanised layer. Preheat is set to 260–290°C and the component is dipped for 3–5 s. Film thickness is controlled at 200–350 µm. Post-cure at 180–190°C for 6–10 min completes the smoothing. The grey pigmentation reduces visible chalking compared with black or white powder coatings, but UV exposure will still alter surface gloss. Accelerated weathering should be conducted with ISO 16474-2 xenon-arc conditions; published colour stability data for grey 7310 AC is limited. Salt spray resistance is evaluated under ISO 9227 for 1,000–2,000 h on galvanised steel with scribe creep measured according to ISO 4628-8. Coastal installations benefit from the low water absorption of PA11, but cut edges must be coated and not left bare because the sacrificial galvanic protection is interrupted by the powder film. The end product is a bus shelter frame, park bench, outdoor handrail, or architectural screen. Fasteners should be installed before coating or masked with silicone plugs; drilling after coating creates corrosion initiation points. Temperature variation in thick cast aluminium nodes can cause local film thickness differences of ±75 µm; those nodes require an additional preheat dwell of 5–10 min or a lower production speed.
Competitive Arkema Rilsan Fine Powders T GREY 7310 AC PA11 prices that fit your budget—flexible terms and customized quotes for every order.
For samples, pricing, or more information, please contact us at +8615365186327 or mail to admin@ascent-chem.com.
We will respond to you as soon as possible.
Tel: +8615365186327
Email: admin@ascent-chem.com
Flexible payment, competitive price, premium service - Inquire now!
Arkema Rilsan Fine Powders T GREY 7310 AC PA11 is a thermoplastic coating powder based on polyamide 11, produced from 11-aminoundecanoic acid. The material is supplied as a grey-pigmented fine powder for fluidized-bed dip coating and electrostatic spray deposition on metallic substrates. The designation T GREY 7310 AC identifies a product family, color index, and formulation variant within the Rilsan Fine Powders portfolio; the AC suffix is grade-specific and the official product datasheet remains the controlling reference for its meaning. Lot-level documentation typically reports particle size distribution by ISO 13320-1 and bulk density by ISO 60. The polyamide 11 backbone has a lower amide density than PA6 or PA66, which contributes to moisture uptake of approximately 0.3–0.4% after 24 h immersion at 23°C per ISO 62. Film formation occurs by melting, flow, and solidification, not by a thermosetting cure reaction.
Powder-state properties control fluidization, charging, and transfer efficiency. The median particle size, D50, for fine powder grades generally falls between 20 µm and 45 µm, but the exact distribution for T GREY 7310 AC must be confirmed on the certificate of analysis because Arkema permits grade-specific adjustments. Particle size distribution is measured by laser diffraction per ISO 13320-1. Bulk density typically ranges from 0.45 g/cm³ to 0.55 g/cm³ by ISO 60. Molten-state properties relevant to flow and surface leveling include a melt temperature of 183–187°C by differential scanning calorimetry per ISO 11357-3 and a fused coating density of 1.03–1.05 g/cm³ per ISO 1183-1. The grey 7310 pigmentation alters opacity and electrostatic charging behavior but does not materially shift the crystalline melt endotherm under normal commercial pigment loadings.
| Property | Test method | Representative value or range |
|---|---|---|
| Median particle size D50 | ISO 13320-1 | 20–45 µm |
| Bulk density | ISO 60 | 0.45–0.55 g/cm³ |
| Melt temperature, DSC | ISO 11357-3 | 183–187°C |
| Fused coating density | ISO 1183-1 | 1.03–1.05 g/cm³ |
| Water absorption, 24 h at 23°C | ISO 62 | 0.3–0.4% |
| Shore D hardness, 15 s | ISO 868 | 70–75 |
| Elongation at break | ISO 527-2 | >150% for unfilled base resin |
These values represent PA11 fine powder bases rather than a single production lot. The certificate of analysis controls acceptance limits for T GREY 7310 AC. The property set indicates that the powder can be processed on standard thermoplastic coating lines without the electrostatic charging additives used in some epoxy-polyester thermosetting powders.
Moisture control is a process boundary. The powder should be stored at 20–25°C and 40–60% RH. If the powder has been exposed to relative humidity above 60% for more than 24 h, pre-drying in a dehumidified hopper or fluidized-bed dryer at 80°C for at least 4 h is required before use. Moisture released during fusion can produce steam pinholes, microvoids, and reduced intercoat adhesion. This failure mode has been observed in fluidized-bed dip coating when ambient humidity exceeds 65% and powder is fed directly from unsealed bags; the resulting film exhibits surface craters and lower cross-cut adhesion per ISO 2409. Drying is not optional for components requiring continuous film integrity under salt spray exposure per ISO 9227.
Substitution of a PA12 coating powder with T GREY 7310 AC is not a direct drop-in conversion. The crystalline melt temperature of PA11 is approximately 183–187°C, while most PA12 coating grades melt at 172–178°C. This shifts the required substrate preheat and fusion settings upward by about 5–10°C at the part surface. On an electrostatic spray line equipped with corona guns operating at 60–80 kV, the part surface temperature should be raised to approximately 220–260°C before powder application to achieve adequate melting and flow. Preheat below 200°C may produce orange peel and poor leveling because melt viscosity remains too high. Fused coating density of PA11 is 1.03–1.05 g/cm³ per ISO 1183-1, slightly lower than typical PA12, which changes film mass at equivalent thickness.
Electrostatic charging may also differ because the grey pigment package can modify surface resistivity. Lower surface resistivity promotes back-ionization; deposition voltage and gun-to-part distance should be adjusted in 5 kV increments until film uniformity is restored. PA11 absorbs approximately 0.3–0.4% at 24 h immersion per ISO 62, while PA12 may be marginally lower because of a longer methylene sequence. The practical consequence is that PA11 requires stricter pre-drying in humid environments. The grey 7310 AC grade differs from natural PA11 fine powders in opacity and surface finish; natural grades are translucent or off-white, whereas the grey variant provides a consistent grey coating with opacifying pigments. Published data for the exact 7310 AC pigmentation are limited, so pilot trials on the target geometry are recommended before full conversion.
Adhesion to steel and aluminum substrates depends on surface profile and preheating. Degreasing followed by grit blasting with 60–80 mesh alumina to a surface profile of 6–12 µm Ra per ISO 8503-2 is recommended for fluidized-bed dip coating. Phosphate conversion coatings can improve corrosion resistance, but adhesion values should be verified by cross-cut testing per ISO 2409 or pull-off testing per ISO 4624. Substrates are then preheated in gas-fired convection ovens to 250–350°C depending on mass and wall thickness. Heavier sections require the upper end of this range to maintain sufficient heat capacity for powder fusion after immersion. Inadequate surface preparation is a common production failure mode, producing smooth but weakly bonded films that fail at the coating-substrate interface under gravelometer testing per ISO 20567-1.
After powder application, the coated part enters a fusion oven. The fusion zone should be controlled at 190–210°C metal temperature for PA11 fine powders, with residence time determined by substrate wall thickness and desired film thickness. Recommended oven air temperature is often 220–250°C to overcome heat transfer lag in thick sections. Film thickness in fluidized-bed dip coating typically ranges from 150 µm to 400 µm for heated parts, while electrostatic spray deposition produces 60 µm to 150 µm films. Oven residence time must not be confused with thermosetting powder cure time. PA11 does not crosslink; the coating undergoes melting, flow, and solidification. Insufficient residence time leaves visible powder grain boundaries and lowers gloss. Excessive oven time above 210°C metal temperature can cause yellowing of the grey pigmented coating and viscosity reduction that leads to sagging on vertical surfaces.
Substrate mass creates thermal lag that influences film formation. For a 10 mm thick steel plate, the preheat oven holding time required to reach uniform temperature is substantially longer than for a 1 mm wire rack. Production lines with mixed part masses often exhibit batch-to-batch variation in film thickness unless temperature profiling with thermocouples is used. Oven air uniformity of at least ±5°C across the working envelope is recommended for consistent color and surface finish. Wider deviations produce edge effects because thinner sections reach melting temperature faster and retain less heat during powder application. Infrared preheating can reduce surface temperature variability for high-volume uniform parts, but published data for infrared-processed T GREY 7310 AC is limited.
Operational boundaries include maximum part surface temperature, powder bed contamination, and film thickness limits. Fused PA11 coatings should not be exposed to continuous service above approximately 120°C without thermal aging validation, because oxidative degradation of the polyamide chain occurs over extended exposure. The powder should not be blended with thermosetting powders, PA6 or PA66 fine powders, or unknown recycled powders. Melting temperature mismatches produce phase separation, specks, and loss of adhesion. The fluidized bed air supply should be filtered to remove oil and moisture; oil mist from rotary-screw compressors creates fisheye defects. Air flow should be adjusted to a dense, boiling-bed condition without slugging; air velocities are typically 1.5–3.0 m/s through the porous plate, but bed geometry and particle size distribution determine the exact setting. Electrostatic spray booths must maintain powder conductivity and humidity control. Relative humidity below 40% can increase tribo-charging and cause powder clumping in feed hoses.
Chemical resistance of PA11 coatings is evaluated by immersion and spot tests using mineral acids, alkalis, and hydrocarbons. PA11 exhibits better resistance to salt solutions and aliphatic hydrocarbons than PA6 or PA66, but concentrated mineral acids and strong oxidizing agents degrade the amide linkage. The grey 7310 AC variant does not change the base polymer resistance; it may affect visual assessment of surface attack because pigmented films mask early discoloration. Regulatory compliance is controlled by the base PA11 chemistry and the pigment package.
| Regulatory or standard reference | Relevance | Status or application |
|---|---|---|
| EU REACH (EC 1907/2006) | Monomer and polymer registration | Consult safety data sheet for registration number |
| RoHS Directive 2011/65/EU | Restriction of hazardous substances | Not expected to exceed thresholds; supplier certificate required |
| FDA 21 CFR 177.1500 | Nylon resins for food contact | PA11 may be suitable subject to final article end-testing |
| EU Regulation 10/2011 | Plastic materials in food contact | Final article migration testing required |
| ASTM D6866 | Bio-based carbon content | Method used to quantify renewable carbon in PA11 |
Food-contact suitability under 21 CFR 177.1500 is not an automatic property of the powder. The final article must meet extraction limits and end-use restrictions. The supplier should be consulted for lot-specific certificates and migration test data per EU Regulation 10/2011 when the coated part is used in food-contact applications. Published test data for T GREY 7310 AC in direct food-contact service are limited.
In fluidized-bed dip coating, particle size distribution determines bed expansion, voidage, and pick-up. Overly coarse fractions settle and reduce bed homogeneity, while excessive fines below 10 µm increase dust emission and can raise occupational exposure. The grey 7310 AC grade is a fine powder, so dust collection with HEPA filtration is required. Sieve residue on a 125 µm screen is normally low, but the certificate of analysis is the controlling record. In electrostatic spray, fine particles below 10 µm can be transported by air currents away from the part, reducing transfer efficiency. High-voltage settings above 80 kV may produce back-ionization and orange peel. Reducing gun voltage and increasing gun-to-part distance can mitigate this defect. Because grey pigment can alter surface conductivity, powder resistivity values should be obtained from the supplier before setting the high-voltage profile.
Electrostatic application to wire goods such as dishwasher baskets requires attention to Faraday cage effects. Open wire geometry allows deposition on leading edges but may leave low film thickness in shadowed areas. Heating the part to 220–260°C before spraying improves powder melt on contact and reduces blow-off. Coating thickness on wire intersections can exceed 300 µm due to electrostatic wrap; this is acceptable for mechanical protection but may affect dimensional fit if component tolerances are below 0.5 mm. Grey 7310 AC provides visual coverage over stainless steel and zinc-plated wire. Batch color consistency depends on powder bed temperature and fusion oven residence time. For applications requiring salt spray resistance per ASTM B117 or ISO 9227, a minimum film thickness of 250 µm is frequently specified, but the exact requirement must be validated on the production part because edge coverage and adhesion may vary.
