For flooded lead-acid and start-stop AGM/EFB batteries, the supplier stack differs entirely: PE sleeve separators, AGM glass-matt rolls, PVC-SiO2 mats, tubular gauntlets and PP flame arrestors are the day-to-day part numbers, with Heilongjiang JinHan Technology (China) operating as a full-line lead-acid components supplier across those categories [S1].
Polyolefin film separators: who makes wet, dry and coated PE/PP
Wet-process biaxially oriented PE sets the wet-electrolyte Li-ion baseline because of its 30-40% porosity, sub-micron pore control and the puncture strength needed for EV and ESS winding; Asahi KASEI's Hipore and SK IE Technology's LiCore line are the most cited grades in this tier [S1].
Dry-process PE/PP multilayers (PP/PE/PP) trade higher melt integrity for slightly lower porosity and remain common in LFP prismatic and cylindrical mass-market cells; Toray's Setela film and SK ie.LiTE (formerly SK Innovation's separator arm) sit in this category [S1].
Lead-acid separator families: PE, AGM, PVC and tubular gauntlets
For flooded lead-acid, a PE separator sleeve is still the most-specified part number globally; thickness typically lands between 0.10 mm and 0.25 mm with controlled back-web porosity to balance ion diffusion against dendrite growth, and the same base polymer is sold as a flat sheet or as an envelope sleeve wrapped around the plate group [S1].
AGM (Absorbent Glass Mat) separators — borosilicate glass microfibres at 80-95% porosity — are mandatory for start-stop EFB and AGM batteries because they hold the electrolyte in a starved-electrolyte cell and recombine oxygen during VRLA operation; the roll format (not sheet) is what the plate-curing and assembly lines consume [S1].
PVC separators with fumed SiO2 filler (PVC-SiO2) cover deep-cyclic traction and stationary flooded batteries where low electrical resistance and high oxidation resistance in sulfuric acid matter, while non-woven tubular gauntlets (polyester or PP) protect the positive plate in tubular OPzS and OPzV cells [S1]. Heilongjiang JinHan Technology markets all four lead-acid separator chemistries in roll, sheet and sleeve formats from a single line, alongside vent plugs, flame arrestors, water-level indicators and rubber O-rings [S1].
Selection criteria: which separator goes in which cell
Specifying a separator is a four-axis problem: electrolyte chemistry (aqueous sulfuric acid vs LiPF6 carbonate), thermal ceiling (130 °C for flooded lead-acid, 150 °C+ for Li-ion with abuse tolerance), format (sleeve, roll, flat sheet, or coated film), and certification (UL 94 V-0 for flame retardancy, RoHS, REACH, IATF 16949 for automotive PPAP) [S1].
The lead-acid side stacks cleanly: flooded starter uses PE sleeves, EFB upgrades to PE-with-carrier or thin AGM, AGM start-stop uses glass-matt rolls, deep-cycle traction shifts to PVC-SiO2, and tubular OPzS/OPzV adds a tubular gauntlet on the positive plate [S1].
Comparison: polyolefin film grades vs AGM/PVC lead-acid separators
A four-criteria comparison makes the split explicit.
On ionic conductivity, the flooded lead-acid separator is soaked in H2SO4 and benefits from very high back-web porosity (60-80%), while Li-ion separators need a tortuous-path sub-micron pore structure with 30-50% porosity and Gurley air permeability tuned to electrolyte wetting [S1].
On end-use fit, polyolefin films go into Li-ion pouch/prismatic/cylindrical cells for EV, ESS and consumer electronics; AGM rolls and PE/PVC sleeves go into SLI, start-stop, traction, stationary and tubular industrial batteries — these two stacks are not interchangeable [S1].
Where these separators actually ship: application fit and limits
For start-stop and flooded industrial batteries, lead-acid separator lines like JinHan Technology's — covering PE sleeve, AGM roll, PVC-SiO2 sheet, tubular gauntlets, PP flame arrestors and battery vent plugs — feed aftermarket and OEM battery assemblers in Asia, the Middle East and Africa [S1]. The same factory stack also includes plate-curing ovens, automatic enveloping and stacking machines, chargers/dischargers, environmental protection machines and battery testing rigs, which matters because separator choice is constrained by what the assembly line can handle [S1].
Supply signals to track into 2H 2026
For context on how separator spec fits into broader battery sourcing decisions, see the cathode chemistry map at Top Cathode Material Companies 2026, the anode side at Anode Material Market 2026, and the electrolyte bottleneck layer at Battery Electrolyte Supply Chain 2026.
For component-level specifications, see cyclone separator, steam separator, and pressure transmitter.