HPMC for Plaster & Gypsum Applications

Plaster and gypsum-based mortars require excellent workability, controlled sag resistance, and sufficient open time, especially in mechanically sprayed applications.

U-4120 is a gypsum-specific modified Hydroxypropyl Methylcellulose (HPMC) developed to meet the processing and performance requirements of lightweight plaster and gypsum mortar systems, ensuring smooth application and improved construction efficiency.

U-4120 – Gypsum-Specific HPMC Grade

U-4120 is a modified HPMC specifically engineered for gypsum-based systems, combining medium-high viscosity with excellent solubility and stability.

It is particularly suitable for mechanically sprayed plaster, where stable rheology and sag resistance are critical.

U-3040/3070/3110/3120/3130/3150

Technical Specifications

ItemSpecification
Product NameU-4120
Chemical NameHydroxypropyl Methylcellulose
CAS No.9004-65-3
AppearanceWhite or light yellow powder
Moisture ContentMax. 8.0%
pH Value5.0 – 9.0
Bulk Density0.3 – 0.5 g/cm³
Particle SizeMin. 90% pass through 80 mesh
Viscosity15,000 – 25,000 cps
Test MethodBrookfield, 20 °C, S6, 20 RPM, 2% solution

Technical Support & Custom Optimization

Plaster and gypsum systems require application-oriented HPMC selection, not generic solutions.

At Keyoung Chemical, we provide targeted technical support to help customers optimize U-4120 performance.

Technical Services Include

  • Dosage optimization for sprayed or manual plaster
  • Sag resistance and open time adjustment
  • Compatibility testing with gypsum and additives

Application Guidance

  • Sample evaluation and formulation advice
  • Troubleshooting for sagging or poor workability
  • Practical recommendations based on construction conditions

Key Properties & Performance Benefits

Excellent Workability

U-4120 significantly improves the workability of plaster and gypsum mortars.

  • Smooth spreading and spraying behavior
  • Easy finishing and leveling
  • Reduced operator fatigue during application
Superior Water Retention

Enhanced Sag Resistance

The controlled viscosity of U-4120 helps reduce sagging, especially on vertical surfaces.

  • Improves shape retention
  • Supports thicker application layers
  • Enhances surface uniformity

Extended Open Time

U-4120 provides sufficient open time for practical construction operations.

  • Allows comfortable adjustment and finishing
  • Reduces application pressure
  • Improves construction efficiency on site
Superior Water Retention

Stable Performance in Gypsum Systems

Designed specifically for gypsum chemistry, U-4120 delivers consistent and predictable performance.

  • Compatible with gypsum binders
  • Stable rheology during mixing and spraying
  • Reliable performance across job-site conditions

Typical Applications

Specific application guidance can be provided based on your formulation and construction method.

Lightweight Plaster

Designed for lightweight plaster formulations, improving workability, sag resistance, and surface smoothness during manual or mechanical application.

Gypsum Mortar

Suitable for gypsum-based mortars requiring stable rheology, extended open time, and consistent construction performance.

Mechanically Sprayed Plaster

Optimized for sprayed plaster systems, ensuring smooth pumping, controlled sagging, and efficient application.

Packaging & Storage

  • 25 kg paper-plastic composite bag with inner PE liner
  • Store in dry and clean conditions
  • Keep away from moisture and heat
keyoung business
Factory Direct Supply

Why Choose Keyoung Chemical

  • Application-focused HPMC manufacturer
  • Dedicated grades for tile adhesive, self leveling, and gypsum systems
  • Stable quality and consistent viscosity control
  • Technical support for formulation and construction optimization
  • Reliable global supply and export experience

RFQs – Frequently Requested Questions

U-4120 is a gypsum-specific HPMC providing excellent workability, sag resistance, and open time in plaster and gypsum systems.

Yes. U-4120 is particularly suitable for mechanically sprayed plaster, offering smooth sprayability and controlled sagging.

The typical dosage is 1.5–2.5 kg per ton, depending on formulation design and application method.

Yes. We offer technical support, dosage optimization, and application guidance for plaster and gypsum mortar formulations.

Request a Quote

Looking for HPMC for plaster and gypsum applications or U-4120 technical support?
Contact Keyoung Chemical to receive samples, formulation guidance, and competitive pricing.

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