On high-throughput wet-process lithium-ion battery separator lines, Celanese GHR UHMWPE 8110 is metered into a paraffinic white oil plasticiser at 22–28 wt% polymer solids; the resulting slurry is starved-fed through a 52–60 L/D co-rotating twin-screw extruder with barrel zones held at 180–230 °C, and the miscible gel is discharged through a coat-hanger die into a quench bath at 20–40 °C to freeze a precursor sheet of 800–1,200 µm thickness. Machine-direction and transverse-direction stretching at 100–125 °C by draw ratios between 5×5 and 7×7 creates lamellar pore channels; residual white oil is removed in a countercurrent n-hexane or methylene chloride extractor until residual plasticiser is below 0.5 wt%, followed by heat-setting at 110–130 °C to lock pore structure. The separator is calendered to 9–20 µm final thickness and tested under ASTM D882 for machine-direction tensile strength, ASTM D4833 for puncture resistance with typical acceptance above 400 gf, and ISO 5636-5 or equivalent Gurley densometer for air permeability. Industry compliance is driven by IATF 16949 clause 8.5.1 for control of production process changes, ISO 14644-1 class 7 cleanroom handling for separator winding, and EU REACH 1907/2006 SVHC declarations at <0.1 wt%. Inorganic filler addition is limited to 0.3–0.8 wt% fumed silica or alumina when surface wettability toward carbonate electrolytes must be improved; transition-metal stearates and primary antioxidants are excluded because their electrochemical oxidation products accelerate capacity fade. Terminal article types are single-layer UHMWPE, PP/UHMWPE/PP trilayer shutdown separators, and ceramic-coated UHMWPE separators used in lithium-ion cell assembly for automotive and grid storage battery packs.

What Draw Ratios Are Applied When GHR UHMWPE 8110 Is Fed Through a 30 mm Gel-Spinning Line?

A heated high-shear dissolver operating at 130–160 °C is charged with decalin or high-purity paraffin oil, and GHR UHMWPE 8110 is fed at 8–15 wt%; hindered phenolic antioxidant is added at 0.05–0.1 wt% of the polymer mass to protect the gel from thermo-oxidative chain scission during dissolution, which typically requires 60–90 min under 10–15 kW/m³ specific mixing power. The gel is then filtered through 20–40 µm sintered metal mesh and metered by a gear pump into a 30 mm single-screw spinning extruder operating at 170–190 °C; spinnerets with 0.6–1.2 mm capillaries feed a water quench bath that gels the filaments at 8–15 °C. Solvent is removed in a two-stage extraction line with boiling heptane or dichloromethane, residual solvent is reduced below 200 ppm, and the dry precursor yarn is multi-stage hot-drawn at 115–150 °C up to a cumulative draw ratio of 60–80:1. The accepted fibre has tensile strength in the range 3.0–3.6 GPa, modulus 100–120 GPa, and elongation at break 2.5–3.5% when tested under ASTM D885; cut resistance is evaluated under EN 388:2016 for gloves and ballistic performance under NIJ 0101.06 or NIJ 0101.07 for soft armour panels. Terminal products include unidirectional ballistic prepreg sheets, cut-resistant textile liners, and high-modulus ropes for offshore mooring, where chemical compliance is documented under REACH and customer-specific restricted substance lists with no intentionally added heavy metals or fluorinated processing aids.

When GHR UHMWPE 8110 powder is charged to ram extruders for solid profiles, no plasticiser or external lubricant is used; the powder is gravity-fed into a heated barrel, compacted by a reciprocating plunger against a die land pressure of 15–25 MPa, and sintered into a continuous profile at barrel temperatures between 200 °C and 230 °C. Formulation is 100% virgin powder for food-contact wear strips; for UV-stabilised outdoor profiles, 1.5–2.5 wt% carbon black masterbatch or 0.3–0.5 wt% hindered amine stabiliser masterbatch is dry-blended. Ram speed is limited to 0.5–2.0 m/h because the high zero-shear melt viscosity of UHMWPE produces melt fracture at the die outlet above this range. Profiles leave the die as a continuous sintered strand, pass through a water-cooled sizing sleeve at 40–60 °C, and are cut to length; internal residual stress is reduced by post-treatment at 65–80 °C for 4–6 h. Dimensional tolerance under DIN 7168 and tensile testing under ASTM D638-14 are used. Compliance for food-contact conveyor components rests on FDA 21 CFR 177.1520(d) and EU 10/2011, while the finished profile is odour-neutral and free from external lubricants. Terminal part types are bottle conveying starwheels, chain guide rails, and wear strips for filling lines in beverage, dairy, and packaging plants.

When Compression Moulding Requires Uniform Oxidation Inhibition Across 40 mm Thick Slabs

Press loading is conducted by charging powder to a matched-metal mould to a pre-compaction density of 0.45–0.50 g/cm³; platen temperature is held at 200–220 °C with a mould pressure of 10–15 MPa. For a 40 mm slab, the heating plateau is held for 20–30 min after the mould core reaches 195 °C, because the low thermal diffusivity of UHMWPE delays through-thickness heat penetration; cooling is controlled at 10–15 °C/min until core temperature is below 60 °C, preventing internal shrinkage voids and warpage. Formulation is 100% GHR UHMWPE 8110 virgin powder for chemical linings, or up to 20 wt% clean in-process UHMWPE trim whose zero-shear viscosity remains within ±5% of virgin material. For liners in mineral handling, 0.5–1.0 wt% phenolic antioxidant may be incorporated only when the lining is not in direct food contact. Compliance with material requirements is established under ASTM D4020-18 for ultra-high-molecular-weight polyethylene molding and extrusion materials, FDA 21 CFR 177.1520 for food-contact use, and EU 10/2011 with overall migration below 10 mg/dm² for fatty food simulants. Terminal articles are compression-moulded sheets, hopper liners, silo liners, and chute liners for mining, cement, and fertilizer handling.

Sintered porous GHR UHMWPE 8110 media are produced by filling mould packs with sieved powder fractions, applying vibratory compaction at 50–80 Hz to achieve a packing density of 0.40–0.48 g/cm³, and heating in a convection oven at 180–210 °C for 30–60 min; no polymeric binder is added, as particle surface melting creates interparticle necks. Pore size is controlled by screening the powder; a D50 of 120–180 µm yields median flow pore diameters of 20–40 µm, while finer cuts below 100 µm yield 8–15 µm pore channels, as measured by capillary flow porometry under ASTM F316. The sintered blanks are skived to final plate thickness, typically 2–15 mm, and machined to flatness of ±0.1 mm/100 mm. Formulation for fluidizing plates is 100% UHMWPE powder; for hydrophobic vent membranes, the sintered surface may be post-treated by fluorination or silicone treatment, but the base polymer is not compounded with low-molecular-weight waxes because they migrate and block pores. Compliance for pneumatic silencers and vent elements falls under ISO 9001 process control, EU REACH, and for potable water contact under NSF/ANSI 61 where applicable to the assembled filter housing. Terminal product types include compressed-air pneumatic silencers, battery pack pressure equalisation vents, porous suction filters for agricultural spray pumps, and fluidizing plates for bulk powder conveying.

Industrial Lead-Acid Battery Separators Composed of Silica-Filled UHMWPE

In flooded lead-acid battery separator extrusion, GHR UHMWPE 8110 is dry-blended with precipitated silica, mineral oil, and carbon black; typical formulation is 12–18 wt% UHMWPE binder, 55–65 wt% precipitated silica, 25–35 wt% naphthenic or paraffinic process oil, and 0.3–0.8 wt% carbon black for acid oxidation resistance. The compound is fed through a 40–60 L/D twin-screw extruder at 160–200 °C, passed through a flat die, calendered to 200–500 µm, and passed through a solvent extraction bath of n-hexane to remove process oil, creating a microporous structure with pore size 0.1–1.0 µm. Backweb thickness and rib profile are formed by thermal embossing at 80–120 °C; the separator is then wound into rolls. Industry compliance is defined by IEC 60095-1:2018 for lead-acid starter batteries and by IATF 16949 controlled production for automotive supply; material chemical registration is documented under EU REACH 1907/2006. Silica filler level directly controls electrical resistance; acceptance limits are set by the battery manufacturer, with typical ranges 0.5–1.0 Ω cm² in 1.280 g/cm³ sulfuric acid at 25 °C. Terminal products are leaf, envelope, and ribbed separators used in automotive, motorcycle, and industrial motive deep-cycle lead-acid batteries.