Ateva 2861A EVA resina de copolímero, 28% VA, 6 MI, fio e cabo grau (LSZH)

Ateva 2861A is a wire and cable grade ethylene-vinyl acetate copolymer containing 28% vinyl acetate and a melt flow index of 6 g/10 min when measured under ISO 1133-1:2022. In low-smoke zero-halogen compound design, this comonomer level functions primarily as a polarity source that permits high loadings of hydrated mineral flame retardants while retaining sufficient chain mobility for extrusion. The application scenarios below are limited to downstream cable and wire manufacturing sectors in which this resin is used on industrial compounding lines; each scenario specifies the compliance framework, formulation addition ratio, production process boundary, and terminal cable type.

Sheathing Compounds for Building Distribution Cable Under EN 50575

Low-voltage building wire compounds formulated with Ateva 2861A as the continuous polymeric phase rely on the 28% vinyl acetate content to accept a filler loading of 140–170 phr aluminium trihydroxide without the immediate elongation collapse observed in lower-VA grades. A standard LSZH sheath addition ratio is typically 100 phr Ateva 2861A, 150 phr aluminium trihydroxide with a median particle size of 1.3–1.8 µm, 10–20 phr magnesium dihydroxide for secondary endothermic cooling, 5–8 phr zinc borate, 1–2 phr aminosilane coupling agent, and 0.6–1.0 phr hindered phenolic antioxidant. The silane dose must be adjusted against the filler bulk density because under-silanized ATH surfaces raise melt viscosity significantly and push barrel temperatures toward the dehydration threshold of the hydrated filler.

Compliance in this segment is evaluated under EN 50575:2014+A1:2016, with single-cable flame propagation tested to IEC 60332-1-2:2015 and bunched cable vertical flame spread to IEC 60332-3-24:2018. Acid gas emissions are quantified according to IEC 60754-2:2019, with pH not below 4.3 and conductivity not above 10.0 µS/mm. Smoke density is measured by IEC 61034-2:2019, and thermal-oxidative stability is assessed by EN 60811-501 after 168 h at 100°C. Because the same base resin can produce Dca or Cca results under EN 50399:2011+A1:2016, the full cable test classification must be confirmed with the selected filler package and zinc borate ratio rather than inferred from resin data alone.

The downstream production sequence is a two-stage operation. First, the compound is mixed in a co-rotating twin-screw extruder with an L/D ratio of 36:1 to 44:1; barrel zones are set between 140°C and 175°C, and the die head is maintained at 160–175°C. The upper limit is not arbitrary: aluminium trihydroxide begins releasing water of crystallisation in the 180–200°C range, so a processing window of ±5°C around 170°C is typical on production-scale lines to prevent pinholes, surface roughness, and screw build-up. A vent port with vacuum below 80 mbar is required because moisture levels above 0.2% in the filler-polymer blend generate porosity. The second stage is jacket extrusion on a single-screw cable line with a compression screw of 24:1 to 30:1 L/D and a screen pack of 100/80/60 mesh, producing low-voltage building wire sheaths with wall thicknesses from 0.6 mm to 2.0 mm.

Terminal product types in this segment include rigid and flexible low-voltage building cables such as H07Z1-K and NHXMH types, as well as CPR-classified multi-core power distribution cables for fixed installation in public buildings, hospitals, and transport infrastructure. Incoming ATH particle-size drift should be controlled at the warehouse gate with laser diffraction acceptance limits because compound viscosity depends more on filler surface area than on the 6 g/10 min melt index of the raw resin in fully filled LSZH systems.

Automotive thin-wall cable manufacture uses the polar vinyl acetate sequence in Ateva 2861A as a compatibilising segment for mineral fillers, while the melt flow index of 6 g/10 min balances compound viscosity against the high shear rates of high-speed insulation lines. The formulation for 0.35 mm and 0.50 mm wall halogen-free automotive conductors generally blends 60–80 phr Ateva 2861A with 20–40 phr linear low-density polyethylene or ethylene-octene copolymer, 90–130 phr aluminium trihydroxide, 5–10 phr zinc borate, 1–2 phr antioxidant, and a process stabiliser package. The LLDPE fraction is not inert; it restores melt strength lost when filler loading rises above 100 phr and prevents tubing draw-down instability in thin-wall crossheads.

Compliance in this automotive segment is based on ISO 6722-1:2011 for dimensional and mechanical performance, with Class C cables evaluated after thermal ageing at 125°C for 3,000 h or 2,000 h depending on wall thickness. Low-smoke behaviour is measured by ISO 5659-2:2017, and halogen-free status is verified by IEC 60754-2:2019. For German automotive homologation, the cable is additionally assessed under LV 112 or the vehicle-maker-specific test specification that imposes stricter smoke toxicity limits than the base ISO text. Compounds destined for Class C under-0.5 mm walls should not exceed 130 phr ATH because elongation after ageing can fall below the 125% requirement when filler dispersion is suboptimal.

The production line for this scenario is a tandem process: a co-rotating twin-screw extruder with 25:1 to 32:1 L/D prepares the LSZH compound, then a 24:1 single-screw extruder with a hard-tipped compression screw applies insulation onto bare copper or tinned copper at speeds of 300–800 m/min. Melt temperature in the cable extruder is kept below 190°C; if screw speed is increased without adjusting the temperature profile, shear heating from the high-viscosity filled melt raises local temperatures above the ATH dehydration threshold and produces surface lumps. Wire preheating at 60–80°C is applied to control adhesion and shrinkback. Fluoropolymer-based processing aids at 200–500 ppm are used on production-scale equipment to reduce melt fracture under high-speed extrusion with 90–130 phr ATH.

Terminal products include thin-wall halogen-free automotive primary wires, battery management system signal conductors, and electric-vehicle auxiliary circuit cables where OEM specifications require low-smoke zero-halogen performance with flexibility at sub-zero temperatures. Published production data for this specific configuration is limited at the upper end of the filler range, so validation runs on 0.35 mm wall thickness remain necessary before fixing the addition ratio.

What Limits Filler Loading in Photovoltaic Jacketing Compounds?

The ceiling on mineral filler loading in photovoltaic cable jackets is set by a combination of long-term wet ageing, thermal endurance at 120°C, and low-temperature impact resistance rather than by initial tensile strength alone. A crosslinkable LSZH formulation for 1.5 kV DC PV cable begins with 55–70 phr Ateva 2861A, 30–45 phr LLDPE or ethylene-octene elastomer, 120–160 phr aluminium trihydroxide, 5–12 phr zinc borate, 3–5 phr UV stabiliser masterbatch, and a silane crosslinking package of 1.5–2.5 phr vinyltrimethoxysilane with 0.08–0.15 phr dicumyl peroxide as initiator. Filler addition above 160 phr is possible in initial compounding, but the hot-set elongation after crosslinking and the -40°C cold impact requirement in EN 50618:2014 begin to diverge from specification because the polymer matrix volume is insufficient to absorb impact energy around filler particles.

Compliance is anchored to EN 50618:2014 for electric cables for photovoltaic systems and IEC 62930:2017 or UL 4703 for export variants. Long-term thermal ageing follows EN 60216-1 at 120°C for 20,000 h, and UV resistance is evaluated under EN ISO 4892-2 cycle A or equivalent. Halogen acid gas emission remains below the IEC 60754-2:2019 limits of pH 4.3 and conductivity 10.0 µS/mm. The critical threshold is hot set: under EN 60811-507, the load at 200°C should produce elongation below 175% and permanent set below 15% after cooling. If hot-set elongation exceeds this limit at the stated filler loading, the silane grafting level must be increased or the LLDPE fraction raised, both of which alter the flame-retardant balance.

The production sequence uses a two-step silane crosslinking route. In the first step, the compound is produced on a co-rotating twin-screw extruder at 150–175°C with a vent vacuum below 80 mbar. EVA granules are pre-dried at 70°C for 4 h when ambient relative humidity exceeds 60%. In the second step, peroxide-initiated silane grafting is performed on a single-screw extruder with a 30:1 L/D screw and a melt temperature limited to 175°C to avoid premature scorch. The cable jacket is extruded onto a solar cable core and then moisture-cured in a water bath at 80–90°C for 8–24 h. Gel content measured by ASTM D2765-16 is typically maintained between 65% and 75%; lower gel content indicates incomplete grafting or steam-bath humidity below the required level.

The terminal product types are single-core flexible photovoltaic cables with conductor cross-sections from 1.5 mm² to 35 mm², dual-wall insulation and jacket systems, and DC system voltage of 1.5 kV. These cables are installed in solar farms and rooftop arrays where halogen-free jacketing is specified to limit corrosive gas exposure to inverters and metallic mounting systems.

When Marine Cables Require Halogen-Free Acid Gas Performance

Shipboard and offshore platform cable compound design under NEK 606:2016 moves the filler strategy toward magnesium dihydroxide, because the higher dehydration temperature of MDH expands the processing window for the thicker jacket walls required in heavy-duty marine power cables. A production starting point is 70–90 phr Ateva 2861A, 10–30 phr ethylene-octene or EPDM for cold flexibility, 120–150 phr magnesium dihydroxide, 20–40 phr aluminium trihydroxide, 6–10 phr zinc borate, and 0.6–1.2 phr antioxidant. The higher MDH fraction increases compound density and melt viscosity, requiring a vinylsilane coupling agent at 1.0–1.5 phr. A practical incompatibility exists when this EVA grade is combined with amine-based char promoters in moisture-cure systems: amine functionalities can interfere with silanol condensation and reduce gel content below the required minimum, so such additives are avoided unless the compounding line has strict temperature control within ±5°C and very low hold-up volume.

Compliance is verified by IEC 60092-359:2014 for physical and chemical properties of sheathing compounds, IEC 60332-3-22 for bunched cable flame propagation, IEC 60754-2:2019 for acid gas, and IEC 61034-2:2019 for smoke density. The IMO FTP Code Part 2 is applied for smoke and toxic product measurement; the material must remain within the specified limits when the full cable bundle is tested. Marine classification society approvals may impose additional mud resistance and hydrocarbon absorption limits, so the filler ratio should be revalidated against the specific NEK 606 production specification rather than adopted as a universal marine compound.

Marine cable jacket production runs on single-screw extruders with L/D ratios of 30:1 to 34:1 because the high MDH compound requires longer plasticising length. Melt temperature must not exceed 180°C. The compound is best fed from a pre-dried intermediate holding hopper at 60–70°C; MDH absorbs moisture strongly, and free moisture above 0.15% yields surface porosity and reduces discharge rate. Venting with vacuum below 60 mbar is recommended. Screw cooling is sometimes used in the feed section to prevent premature fusion and to maintain throughput stability in thick-wall sheaths of 1.5–4.0 mm.

Terminal product types include halogen-free offshore power and control cables, mud-resistant shipboard cables, and cables for naval and merchant vessels requiring NEK 606 approval. The 28% VA content in Ateva 2861A contributes to resistance against hydrocarbon absorption, but cable designers must validate the specific mud formulation because mineral filler type and surface treatment affect the final oil-resistance profile.

Where data-centre riser and fibre backbone cables are evaluated under EN 50399:2011+A1:2016, the moderate melt flow index of 6 g/10 min in Ateva 2861A becomes an important lever for reducing screw pressure and maintaining line speed during the extrusion of thin LSZH jackets over large pair counts. A representative addition ratio for a CPR-classified data cable sheath is 70 phr Ateva 2861A, 30 phr LLDPE, 130–150 phr aluminium trihydroxide, 5–8 phr zinc stannate, 2–4 phr silicone processing aid, and 0.8–1.2 phr antioxidant. Zinc stannate modifies char formation and smoke suppression, while the silicone processing aid reduces die deposits at high line speeds. Filler loading is typically held at the lower end of the range when the jacket wall falls below 0.8 mm because surface defects become more visible in continuous extrusion trials.

Compliance is driven by EN 50575:2014+A1:2016 and the test methods in EN 50399:2011+A1:2016 for heat release and flame spread, IEC 60332-1-2:2015 for single-cable flame propagation, IEC 61034-2:2019 for smoke density, and IEC 60754-2:2019 for acid gas. North American market variants may be evaluated under NFPA 262 or UL 1685, but the formulation must be revalidated because the test geometry and flaming conditions differ from the EN methods. The limiting factor in high-line-speed data cable sheathing is not the base resin but filler dispersion: agglomerates above 25 µm initiate surface pinholes and reduce the smoke-density margin, so filler sieve residue should be controlled accordingly.

Compounding is performed in a co-rotating twin-screw extruder with 32:1 to 40:1 L/D, with an upstream side feeder for ATH and a downstream side feeder for zinc stannate to avoid early degradation. The cable sheathing line uses a 24:1 to 30:1 single-screw extruder with a Maddock mixing tip and a low-compression screw. Melt temperature is maintained at 155–175°C, and the water trough distance is increased relative to unfilled polyolefin sheathing because filled EVA compounds require slower cooling to avoid shrinkback. Line speeds of 200–400 m/min are achievable for jackets with wall thicknesses of 0.6–1.2 mm, but published production data for this specific configuration is limited above 400 m/min.

Terminal products are LSZH riser and distribution communication cables for data centres, fibre backbone cables with halogen-free jackets, and CPR Cca or Dca compliant copper data cables. The jackets are used in conduit and riser installations where smoke opacity and acid gas release are constrained by local building permits.

Railway Rolling Stock Cable Jacketing — EN 45545-2 Hazard-Level HL3 Compliance

The fire-safety framework for rolling stock cables imposes simultaneous limits on heat release, smoke density, and toxic gas emissions that cannot be met by simple PVC replacement. LSZH jacketing compounds built on Ateva 2861A for this sector use 60–80 phr of the EVA resin, 20–40 phr ethylene-octene or LLDPE, 120–160 phr aluminium trihydroxide, 10–25 phr magnesium dihydroxide, 8–12 phr zinc borate, and 1.5–2.5 phr intumescent char former. The addition of a char former is specific to this segment because EN 45545-2:2013+A1:2015 hazard-level requirements for HL3 demand a lower heat release rate than standard building cable classifications; the char layer must form early enough to limit thermal feedback but late enough not to disturb extrusion viscosity.

Compliance is tested under EN 45545-2:2013+A1:2015 for hazard level HL3, using ISO 5659-2:2017 for smoke density and ISO 5660-1 for heat release. Mechanical requirements for railway cables are referenced in EN 50264-1 and EN 50306-2. Acid gas is capped by IEC 60754-2:2019. The operational boundary for this grade is established by the maximum processing temperature of 180°C; below this, the zinc borate and char former are not activated prematurely, but above this, the compound develops pressing torque instability as the intumescent system partially decomposes.

Production for railway jacket compounds is a two-step process: first, all ingredients are melt-mixed in a twin-screw extruder with 36:1 L/D at 140–170°C; second, the jacket is applied in a single-screw extruder with 30:1 L/D and a barrier screw. If thin-wall railway cables are to be electron-beam crosslinked, the compounded material is extruded at 150–165°C, then irradiated at 120–160 kGy to achieve a gel fraction above 70% per ASTM D2765-16. For thick-wall jumpers, silane moisture curing is used instead. The upper limit of 160 phr ATH is not simply a mechanical constraint; railway cable manufacturers report that crossing this threshold lowers the onset of dripping under radiant heat, which is a negative indicator in the EN 45545-2 classification.

Terminal products include halogen-free rolling stock control and jumper cables, thin-wall wire for rail vehicles, and metropolitan transit power and signal cables. The product types require dimensional stability after thermal cycling from -40°C to 125°C, which the formulated EVA matrix accommodates only if the filler is fully coupled and the amorphous phase retains sufficient chain mobility.