Strong Acid Cation Exchange Resin 001×7.5: field notes, specs, and what actually works

If you’re evaluating an acid cation resin for water treatment, you’ve probably noticed the market is noisy. To be honest, procurement teams keep asking for dependable capacity, fast lead times, and data that maps to real standards—not just glossy claims. That’s why the Strong Acid Cation Exchange Resin 001×7.5 from LiJi Resin (polystyrene–DVB, gel type, sulfonated; essentially a solid “sulfuric acid” functionality) has been getting a lot of attention in industrial demin and softening trains.

What it is and why plants are switching

Model 001×7.5 is a gel-type strong acid cation resin based on a polystyrene matrix with ~7.5% DVB crosslinking and sulfonic acid (–SO3H) groups. It’s a workhorse for boiler feed, food & beverage polishers, and mixed-bed deionization. The origin is NO.2 East Jianshe Road, High-Tech Industrial Development South Zone, Wei County, Xingtai, Hebei, China. Many customers say it’s “boringly reliable”—which, frankly, is exactly what you want in a cation bed.

Industry trend, in brief

Plants are consolidating SKUs, moving to resins that balance capacity with lower pressure drop and easier regeneration. There’s also a push for NSF/ANSI 61 compliance where potable contact is in scope and for test reporting aligned to ASTM/GB standards. Surprisingly, price deltas across vendors are narrowing; delivery time and QC traceability now decide winners.

Typical specifications (real-world values may vary)

Parameter	Typical value (≈)	Test/Standard
Matrix / Type	Polystyrene–DVB, gel, 7.5% crosslink	Product design
Functional group	Sulfonic acid (–SO3H)	ASTM D2187
Total capacity	≈1.9–2.1 eq/L (Na+ form)	ASTM D2187
Moisture retention	≈43–48%	ASTM D2187
Particle size (mm)	0.6–1.2; UC ≤1.6	Sieve, ASTM E11
Operating pH	0–14	Vendor guideline
Max temp	≈120°C (Na+), ≈100°C (H+)	Vendor/ASTM practice
Shipping weight	≈800–850 g/L	ASTM D2187

Process flow and QA

Materials: styrene, DVB, sulfonation with sulfuric acid; Methods: suspension polymerization → bead sorting → sulfonation → conversion (Na+ or H+) → rinsing → QC. Testing covers capacity, moisture, fines, osmotic shock, Fe content, and rinse conductivity. Typical service life: 3–5 years in softening; 2–4 years in demin (depends on fouling, oxidants, and regeneration discipline). Certifications often requested: ISO 9001 quality management; NSF/ANSI 61 for drinking-water contact where applicable.

Application scenarios

• Softening (Na+ form, regenerated with NaCl) upstream of RO to protect membranes.
• Demineralization (H+ form, regenerated with HCl or H2SO4) paired with strong-base anion.
• Mixed-bed polishing for ultrapure rinse water in electronics (with resin traps, obviously).
• Food & beverage deashing and boiler-feed makeup. Several breweries report stable ΔP over a year.

Vendor snapshot: how 001×7.5 stacks up

Vendor	Capacity (≈ eq/L)	Lead time	Certs	Notes
LiJi 001×7.5	1.9–2.1	≈2–4 weeks	ISO 9001; NSF/ANSI 61 (on request)	Solid price/performance; custom bead sizes.
International Brand X	1.9–2.0	≈4–8 weeks	Global potable approvals	Premium pricing; broad distributor network.
Regional Supplier Y	1.8–2.0	≈1–3 weeks	ISO 9001	Competitive lead time; limited test reports.

Customization

Options include tighter UC (≈1.2–1.4), narrow cut (0.6–0.8 mm) for lower ΔP, pre-converted H+ or Na+ shipping form, and tailored rinsing conductivity. For chloride-sensitive lines, HCl regeneration guidance is supplied; for sulfate-limited wastewater permits, NaCl/Na+ cycling may be preferred. It seems small tweaks in bead size pay off in mixed beds.

Two quick case notes

Power plant, 40 m³/h demin: swapping to this acid cation cut regenerant acid by ≈8% thanks to better kinetics, per operations log. Beverage plant, 20 m³/h softener: 10 months stable hardness leakage

Standards, testing, and compliance checkpoints

• Physical/chemical tests per ASTM D2187 and in-house QC; water quality validation per GB/T 5750.
• Potable contact: target NSF/ANSI 61 where required by spec.
• Quality system: ISO 9001 documentation, batch CoA, and lot traceability.

Citations: [1] NSF/ANSI 61 Drinking Water System Components. [2] ASTM D2187 Standard Test Methods for Ion-Exchange Resins. [3] GB/T 5750 Standard Examination Methods for Drinking Water. [4] ISO 9001:2015 Quality Management Systems.