Product overview
Construction-grade sodium CMC is a lower-purity, cost-effective cellulose ether for water retention, thickening and binding in putties, interior coatings and gypsum products. For cement-based tile adhesives and renders, HPMC or MC usually performs better.
Grades and specification
| Grade | Viscosity, 2% (mPa·s) | Purity, % | Degree of substitution | pH |
|---|---|---|---|---|
| HL-1 | 10–50 | 55 ± 2 | 0.6 | 8–10 |
| HL-2 | 80–120 | 40 ± 2 | 0.6 | 8–10 |
| HL-3 | 150–250 | 42 ± 2 | 0.6 | 8–10 |
| HL-4 | 250–350 | 50 ± 2 | 0.6 | 8–10 |
| HL-5 | 100–200 | 50 ± 2 | 0.6 | 6–9 |
| HL-6 | 200–300 | 55 ± 2 | 0.6 | 6–9 |
| HL-7 | 300–400 | 55 ± 2 | 0.6 | 6–9 |
| HL-8 | 500–600 | 55 ± 2 | 0.6 | 6–9 |
| HL-9 | 800–1,200 | 70 ± 2 | 0.65 | 6–9 |
| HL-10 | 70–120 | 82 | 0.2 | 9–13 |
All grades: moisture ≤ 10%. Values are from our current product data. Confirm the exact grade and limits with the TDS and the COA of the lot you test.
Applications
- Wall putty and skim coats: water retention and workability
- Water-based interior coatings: thickening and storage stability
- Gypsum products: water retention and binding
Where construction-grade CMC fits
CMC thickens and holds water well in neutral systems such as gypsum plasters, interior wall putty and water-based coatings. In cement systems, calcium ions released during hydration react with CMC and reduce its efficiency, so cement-based tile adhesives and renders normally use HPMC or MC instead.
| Product | CMC suitable? | Usual cellulose ether |
|---|---|---|
| Interior wall putty (gypsum or lime) | Yes | CMC or HPMC |
| Gypsum plaster | Yes | CMC, HPMC, MC |
| Cement tile adhesive | Limited | HPMC or MC with starch ether |
| Water-based interior paint | Yes | CMC or HEC |
How to choose a grade
Pick by the viscosity you need at your dosage, then by purity: higher-purity grades need a lower dose. Compare with HPMC in cement-based systems.
Packing and documents
25 kg multi-wall paper bags with an inner PE liner. Other packing is agreed per order. TDS, SDS and a representative COA are available for every grade, and each lot ships with its COA. Request documents or a sample.
Related products
Related guides
FAQ
CMC or HPMC in dry-mix mortar?
HPMC is usually preferred in cement mortars and tile adhesives because it tolerates the alkaline, calcium-rich system better. CMC is common in putties and gypsum.
Which CMC grade for wall putty?
Mid-viscosity grades such as HL-3 to HL-6 (150–400 mPa·s at 2%) are common; adjust dosage for water retention and workability.
Why is purity lower in construction-grade CMC?
The remaining part is mainly sodium chloride and sodium glycolate from the reaction. In putty and plaster this salt is acceptable, and lower purity keeps cost down.