China's leading manufacturer of Gypsum Setting Retarder, offering Plaster Retarder solutions.
As a critical additive in gypsum-based systems, our gypsum setting retarder solves the common challenge of fast gypsum setting, which often leads to uneven application, waste, and reduced construction efficiency. With stable production, export experience, and technical support, McKem helps global customers source consistent, high-performance plaster retarder tailored to their specific gypsum formulations and project needs.
Gypsum retarder is a chemical admixture that slows down the hydration reaction of gypsum (calcium sulfate hemihydrate), extending its initial and final setting time. This gives workers sufficient time to mix, transport, apply, and smooth gypsum-based materials before they harden.
Unlike general concrete retarders, our gypsum setting retarder is specially formulated to interact with gypsum’s unique hydration process. It works by adsorbing onto the surface of growing gypsum crystals, inhibiting their growth and delaying the formation of solid gypsum dihydrate.
Our product is available in powder form and compatible with all common gypsum types, including plaster of Paris, building gypsum, high-strength gypsum, and anhydrite. It is widely used in gypsum mortar, plasterboard production, pre-mixed gypsum, art plaster, and other gypsum-based applications.
Gypsum retarder works by adsorbing onto the surface of gypsum crystal nuclei, inhibiting crystal growth and hydration reactions to delay the setting and hardening of gypsum.
Note: Dosage may vary based on gypsum purity, temperature, humidity, and desired setting time. We recommend pre-testing to optimize dosage for your specific application.
| Parameter | Standard Value |
|---|---|
| Product Name | Gypsum Retarder |
| Main Component | Organic acid complex / Polycarboxylate-based polymer |
| Appearance | White to off-white powder |
| Recommended Dosage | 0.1%–0.8% of gypsum weight (adjust based on required setting time) |
| pH Value (1% solution) | 5.0–7.0 |
| Water Insoluble Matter | ≤0.5% |
| Shelf Life | 12 months (sealed, dry conditions) |
| Compatible Gypsum Types | Building gypsum, plaster of Paris, high-strength gypsum, anhydrite |
| Packing | 25 kg woven bag with PE inner liner; OEM packaging available |
By choosing right products, you can optimize crack resistance, toughness, and durability across a wide range of concrete projects.
Our gypsum retarder allows for 1–6 hours of extended setting time (adjustable by dosage), giving workers full flexibility to complete application and finishing work without rushing.
Unlike low-quality retarders, our product does not reduce the compressive strength, bond strength, or weather resistance of hardened gypsum materials.
Extends the open time of gypsum plasters, making them easier to spread, level, and smooth. This results in a more uniform, professional finish for walls, ceilings, and decorative surfaces.
Compatible with all common gypsum types, as well as other additives like cellulose fibers, polyvinyl alcohol (PVA), and water-reducing agents, allowing for flexible formulation design.
Maintains consistent retardation performance across different temperatures (5–35°C) and humidity levels, ensuring reliability in diverse construction environments.
Our gypsum retarder is non-toxic, odorless, and meets international environmental standards, safe for both workers and end-users.
Michem understands that global buyers need more than just a product—they need a reliable partner with consistent quality, technical support, and export expertise. Here’s why we stand out:
We offer tailored gypsum retarder grades with different retardation strengths, allowing customers to match their specific setting time requirements for various gypsum applications.
Each batch of our gypsum setting retarder undergoes rigorous testing for retardation efficiency, strength retention, compatibility, and stability to ensure consistent performance.
Our team of experts helps customers optimize dosage, adjust formulations for local gypsum types, and troubleshoot application issues to ensure optimal results.
Our retarder is highly concentrated, requiring only low dosages, which reduces overall material costs while improving construction efficiency.
Our gypsum retarder plays an irreplaceable role in concrete construction projects due to its superior water reduction rate.
Choose the right form based on your production and logistics needs:
| Grade | Appearance | Bulk Density(g/L) | Moisture Content | Prefabricated Gypsum Components | Caulking Gypsum | Gypsum Putty | Gypsum Plaster | Gypsum Based Self Leveling |
|---|---|---|---|---|---|---|---|---|
| GR150 | Light yellow powder | 700+100g/L | ≤3% | ●●● | ●● | ●●● | ●●● | / |
| GR200 | Light yellow powder | 700+100g/L | ≤3% | ●● | ●● | ●●● | ●● | ●●● |
| GR300 | Light yellow powder | 700+100g/L | ≤3% | ●●● | ●●● | ●●● | ●●● | ●●● |
To maximize the performance of our gypsum retarder, follow these guidelines:
Dissolve the retarder in water first, then add to gypsum powder and mix thoroughly. Avoid direct mixing with dry gypsum.
Start with a low dosage (0.1%) and increase gradually to achieve the desired setting time. Higher temperatures or high-gypsum purity may require slightly higher dosages.
Store the retarder in a dry, cool place to prevent moisture absorption and maintain effectiveness.
Always conduct small-scale tests with your specific gypsum type, additives, and environmental conditions before large-scale use.
Gypsum retarder is specifically formulated for gypsum-based materials, targeting gypsum’s unique hydration process. Concrete retarders are designed for cement and do not work effectively on gypsum.
No. Our high-quality gypsum setting retarder only delays setting time and does not compromise the final compressive strength, bond strength, or durability of hardened gypsum materials.
Depending on dosage, our product can extend setting time from 1 to 6 hours. Higher dosages result in longer setting times.
Yes. Our plaster retarder is compatible with common gypsum additives like cellulose fibers, PVA, water reducers, and air entrainers.
Yes. We offer free or low-cost samples for lab or on-site testing. Contact our sales team to request samples.
We support both small trial orders and large bulk shipments. MOQ varies by packaging and customer needs—contact us for details.
Submit your formulation system to receive customized HEC selection recommendations.
Samples shipped within 48 hours, accompanied by batch stability comparison reports.
Annual framework agreements enjoy priority scheduling + tiered pricing.
No.277 Gongye N Road, Licheng, Jinan,Shandong, China 250000
Tell us about your construction type, raw materials, and performance goals. Our team will recommend the best admixture solution and provide free samples for testing.
We will provide professional solutions to you promptly!
