Description

Plaster of Paris (Ca(SO4).1/2H2O) is a fine, white powder composed of calcium sulfate hemihydrate, known for its unique property of setting into a hard mass when mixed with water. This rapid-setting characteristic makes it an indispensable material for creating precise molds, casts, and rigid forms across diverse industries. It is a critical raw material for professionals in construction, art and sculpture, medical orthopedics, and ceramics manufacturing who require reliable, fast-setting, and dimensionally stable gypsum products.

Application

• Construction & Building Materials: Key component in gypsum plaster, wallboards, ceiling tiles, and decorative moldings for interior finishing.
• Medical & Dental: Used for orthopedic casts to immobilize fractures and in dentistry for creating precise molds and dental models.
• Art, Sculpture & Crafts: Essential for making detailed casting molds, sculpting models, and various craft projects due to its fine detail capture.
• Ceramics & Pottery: Employed in the production of molds for slip casting ceramics and as an additive to control the setting time of ceramic slips.
• Fireproofing: Used as a component in fire-resistant coatings and boards due to the release of water vapor when heated, which helps retard flame spread.
• Soil Amendment: Applied in agriculture to improve soil structure, particularly in sodic soils, by providing calcium and sulfur.

Basic Information

Product Name	Plaster of Paris
CAS No.	26499-65-0
Molecular Formula	CaSO4·0.5H2O or CaSO4.1/2H2O
Molecular Weight	145.15 g/mol
Synonyms	Calcium Sulfate Hemihydrate; Calcined Gypsum; Gypsum Plaster; Stucco; Plaster; Dried Calcium Sulfate; Alabaster; Parisian Plaster; β-Calcium Sulfate Hemihydrate; Bassanite
EINECS	247-781-0

Quality Control

Our Plaster of Paris is manufactured under strict process controls to ensure consistent setting time, strength, and purity. Quality is verified through rigorous testing of key parameters including purity, fineness, and setting characteristics. While we offer standard industrial and technical grades, production can be aligned with specific industry requirements. Certificates of Analysis (COA) documenting lot-specific results are available upon request.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, and well-ventilated area. This product is hygroscopic (moisture-sensitive) and must be kept in its original, sealed packaging until use to prevent premature exposure to atmospheric moisture, which can compromise its setting properties. Ideal storage temperature is between 15°C and 25°C (59°F and 77°F).

Specification

Item	Specification
Appearance	Fine, white to off-white powder
Identification (IR)	Conforms to Calcium Sulfate Hemihydrate
Assay (as CaSO4.1/2H2O)	≥ 95.0 %
Setting Time (Initial)	5 - 15 minutes
Fineness (Residue on 150µm sieve)	≤ 1.0 %
Loss on Drying	≤ 2.0 %

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.