HANWHA EVA 1159

HANWHA EVA 1159 is supplied as a 15 wt% vinyl acetate ethylene-vinyl acetate copolymer with a melt flow rate of 0.9 g/10 min at 190°C/2.16 kg according to ISO 1133-1:2022 and a density of 0.938 g/cm³ per ASTM D792-20. The grade sits between low-VA packaging resins and high-VA encapsulant or hot-melt grades, so the downstream sectors described below are limited to those in which 15 wt% vinyl acetate content and low melt flow rate are documented process inputs rather than extrapolations.

Closed-cell foam expansion control on two-roll mills and compression presses

When the grade is converted into closed-cell crosslinked midsole foam, the semicrystalline ethylene segments and 15 wt% vinyl acetate comonomer provide the melt extensibility required on batch two-roll lines. In a typical formulation, EVA 1159 is charged at 100 phr as the base resin; dicumyl peroxide is added at 0.5–1.2 phr to establish a gel fraction between 60% and 85% after cure. Azodicarbonamide decomposes in the 195–205°C region and is added between 1.5 phr and 3.5 phr, which yields apparent foam density from 0.28 g/cm³ to 0.12 g/cm³. Zinc oxide at 1.0–2.5 phr and stearic acid at 0.4–1.0 phr lower the azodicarbonamide decomposition onset and improve cell nucleation; calcium carbonate at 10–25 phr increases hardness and reduces dimensional shrinkage after demolding. The mixing operation is carried out on a 450–550 mm roll diameter two-roll mill with front-roll temperature 105–115°C and friction ratio 1:1.2. Batch sizes above 35 kg are observed to produce edge cooling below 90°C, causing nonuniform peroxide distribution and localized overcrosslinking. The sheet is then cut and charged into a 300–500 t compression press at 160–170°C and 15–20 MPa for 8–12 min. Decompression rate is controlled below 0.05 MPa/s; faster release blows out the hot foam core before the skin has cooled below the crystallization onset. Compliance for exported footwear midsoles is assessed by ISO 812:2017 for compression set of cellular rubber, ASTM D395-16 Method B for compression set at 23°C, and ASTM D2240-15 for Asker C durometer values. If phthalate plasticizers are present in any layer, EU REACH EC 1907/2006 Annex XVII entry 51 restricts DEHP, DBP, BBP, and DIBP to 0.1 wt% individually in the plasticized material. Terminal parts produced from this process include single-density running shoe midsoles, dual-density trail shoe midsoles, footbed inserts, and crosslinked sandal sheet. Pre-drying at 70–80°C for at least 4 h is required when resin storage humidity exceeds 60% RH, because residual moisture above 0.05 wt% produces irregular cell coalescence and visible pinhole defects along the mold parting line.

What governs filler dispersion limits in XL-HFFR cable sheathing compounds?

EVA 1159 functions as the polar polymer fraction in halogen-free flame-retardant cable compounds where its 15 wt% vinyl acetate content increases filler wetting relative to neat low-density polyethylene. The central process conflict is melt viscosity rise as aluminum hydroxide content exceeds 120 phr because the resin melt flow rate of 0.9 g/10 min already contributes high melt strength. On a co-rotating twin-screw extruder with L/D 44:1 and screw speed 300–450 rpm, the barrel zones from feed to die are set to 100–110°C, 115–125°C, 125–135°C, 135–145°C, 140–150°C, and 145–155°C; die pressure is held under 12 MPa. Aluminum hydroxide is introduced through a side-stuffing feeder at zone 5 rather than through the main feed to avoid lubricant-starved mixing and secondary agglomerates. In a representative low-voltage insulation formulation, EVA 1159 is used at 40 phr, LLDPE at 10 phr, precipitated aluminum hydroxide at 120–140 phr, magnesium hydroxide at 20–40 phr, zinc borate at 5–15 phr, vinyl silane coupling agent at 0.5–1.5 phr, and hindered phenolic antioxidant at 0.3–0.8 phr. The total filler volume fraction is between 40 vol% and 55 vol%; above 55 vol%, torque rises sharply and melt fracture appears at the die. The compound must comply with IEC 60754-1:2011 and IEC 60754-2:2019 for halogen gas emission, IEC 61034-2:2005+AMD1:2019 for smoke density, and IEC 60332-1-2:2015 for single-wire vertical flame propagation. For appliance wiring under EU RoHS Directive 2011/65/EU Annex II, lead, mercury, cadmium, and hexavalent chromium are each limited to 0.1 wt% in homogenized material, and organobromine flame retardants are intentionally excluded. Vacuum degassing at −80 kPa in zone 9 reduces volatiles below 200 ppm, which is critical for stable smoke-density batch-to-batch variance. The processed granulate is then extruded as insulation or sheath over copper conductors on a crosshead die; after radiation or silane crosslinking, the product family includes low-voltage power cable sheathing, control cable insulation, and halogen-free appliance wiring. Fatty acid amide slip additives should remain below 0.1 phr because they compete with silane grafting on aluminum hydroxide surfaces and weaken the interfacial bond required for char integrity.

For automotive mat and pedal-cover tooling, EVA 1159 is molded at melt temperatures of 160–180°C, which is low enough to co-inject flame-retardant backings without thermal degradation of the backing layer. The material is processed on a 350–650 kN toggle press with a 20:1 L/D general-purpose screw and compression ratio 2.2:1–2.6:1. Injection speed is held in the 20–45 mm/s range for parts with wall thickness 2–4 mm; filling thinner sections at higher speed produces shear-induced surface defects at gate regions. In a flexible floor mat compound, EVA 1159 is blended with 10–25 wt% polyolefin elastomer, 2–5 phr paraffinic oil, and 0.05–0.2 phr hindered phenolic antioxidant. For black exterior-adjacent components, 1–2 phr carbon black is added; for grey or tan interior mats, 0.2–0.5 phr HALS and 0.2–0.4 phr benzotriazole UV absorber are substituted. Mold shrinkage is measured at 1.3–1.8% on plaques according to ISO 294-4:2018; this range requires gate and runner dimensions to be oversized by 15% relative to semicrystalline polypropylene tooling. Automotive interior flammability is governed by FMVSS 302 and ISO 3795:1989, with horizontal burn rate not exceeding 102 mm/min; the grade in filled formulations typically passes without halogenated additives when the paraffinic oil content remains below 3 phr. Fogging is evaluated by ISO 6452:2021 or SAE J1756, and low-molecular-weight oil levels above 3 phr increase gravimetric condensate above 2 mg, which violates common OEM specifications. Terminal parts produced under these boundary conditions include automotive floor mats, trunk liners, pedal covers, and interior scuff plates. The low melt flow of 0.9 g/10 min excludes thin-wall parts below 1.5 mm and long-flow tools with flow length-to-thickness ratios above 150:1; published data for this specific grade in hot-runner systems with less than 2.0 mm gate diameter are limited, so pin-point gating should be avoided.

When EVA 1159 replaces flexible PVC in industrial low-pressure tubing

Extrusion conversion of EVA 1159 into low-pressure tubing for pneumatic and protective applications is established on 24:1 or 30:1 L/D single-screw extruders with a barrier screw and 60/80/60 mesh screen pack. The practical thermal stability limit for this grade is 200°C; residence times above 10 min at 200°C are associated with acetic acid odor and surface tack, so the barrel profile is capped at 160°C. The melt temperature profile is set at 120–130°C in the feed zone, 130–145°C in the compression zone, 145–155°C in the metering zone, and 150–160°C at the die. Melt pressure is held between 8 MPa and 15 MPa, and the draw ratio is maintained at 1.1:1–1.3:1 to prevent wall thickness variation above ±0.05 mm. In flexible tube formulations, the grade is used neat or with 5–15 phr LDPE to raise melt extensibility; fluoropolymer processing aid is added at 0.3–1.0 wt% only when melt pressure exceeds 15 MPa at the breaker plate. Carbon black at 1–3 phr is sufficient for UV stabilization; above 4 phr, weld line strength at the die spider legs decreases and burst pressure drops by more than 10% in production burst testing. Compliance for industrial hose jackets is verified by ISO 37:2017 for tensile strength and elongation at break, DIN 53516 for abrasion resistance, and ISO 1307:2006 for bore tolerance on finished tube assemblies. Where the material is compounded into food-contact transfer tubing, the finished article must comply with FDA 21 CFR 177.1350 for ethylene-vinyl acetate copolymers and EU Regulation 10/2011 overall migration limits below 10 mg/dm² using simulant D2 for fatty food contact; industrial transfer lines for dilute acids also require chemical compatibility testing per ISO 4433-1:1997 before specification. Terminal parts include pneumatic tube jackets, cable conduit, protective sleeving, low-pressure return lines, and flexible duct connectors. Pre-drying at 70°C for 3–4 h is necessary when exposed resin exceeds 0.05% moisture; otherwise surface roughness appears as orange peel at the calibration sleeve.

Where crosslinked EVA 1159 block is converted into CNC-machined orthotic supports and impact-absorbing packaging inserts, the grade is first compounded with a blowing agent masterbatch and a peroxide masterbatch on a 90 mm twin-screw extruder at 95–110°C to avoid premature peroxide decomposition. The formulation uses EVA 1159 at 100 phr, dicumyl peroxide at 0.5–1.0 phr, azodicarbonamide at 2.0–4.0 phr, zinc oxide at 1.5–3.0 phr, and calcium carbonate at 5–20 phr. Expansion ratio is limited to 1.5:1–1.7:1 for orthotic shell material requiring Asker C 55–65; packaging insert foam is allowed to reach 1.8:1–2.5:1, but edge collapse risk increases when mold filling ratio exceeds 95% of cavity volume. Foaming is performed in a multi-platen compression press at 165–175°C and 10–20 MPa; cooling under pressure to below 50°C before demold stabilizes cell walls and reduces post-demold shrinkage below 1.5%. Blocks of 40–80 mm thickness are conditioned at 23±2°C and 50±5% RH for 24–48 h before CNC milling at 20,000–40,000 rpm with carbide tooling. For skin-contact orthotic applications, ISO 10993-5:2009 cytotoxicity testing is required on the final component because polymer-process residuals can migrate under warm, occluded conditions; ISO 3386-1 compression stress-strain and ASTM D3575 flexible cellular olefin foam methods define the mechanical acceptance envelope. Compounded material is also assessed against EU REACH EC 1907/2006 and RoHS Directive 2011/65/EU Annex II substance restrictions. Terminal products include CNC-machined foot orthoses, heel cups, anti-fatigue matting, impact-absorbing packaging inserts, and equipment case liners. Published data for this specific grade in long-term skin-contact use are limited, so the orthotic application is restricted to short-term contact designs unless the final component is sealed with a non-porous layer.