CAS: 7778-18-9
Calcium Sulfate Beta Hemihydrate Plaster, known as Plaster of Paris, is a type of calcium sulfate that forms when dihydrate calcium sulfate (natural gypsum) is heated to between 150°C and 180°C, thus expelling most of its water content. This operation gives rise to a fine powder which, upon contact with water, hardens rapidly, establishing an exothermic process. It is commonly employed in construction due to its moldability and quick setting time.
Another interesting fact is that the name "Plaster of Paris" is derived from the gypsum deposits in the Paris area, where it served in construction and arts through history.
Chemical properties of calcium sulfate beta hemihydrate plaster CB.
● CAS: 7778-18-9
● Molecular Formula: CaSO4.1/2H2O
● Wet Compressive strength (Mpa): 5
● Water to plaster ratio ( by weight): 70%
● Plaster to Water Ratio (by weight): 1.43:1
● Plaster to water mix ratio (by weight) Colour: 100/70 off-white
Physical Properties
● Appearance: White or light gray powder
● Texture: Fine and porous, ideal for replicating intricate details in molds
● Durability: Retains its shape with minimal shrinkage after setting
● Setting Time: Between 15-20 minutes after mixing with water, allowing for quick and efficient work
Applications of the Construction Industry
Plaster of Paris is a right choice in construction with several advantages. Molding, quick setting, and resistance to fire make it fitting for:
● Architectural Finishes and Detailing: It is applied for artistic features on walls, ceilings, and similar structures.
● Wall and Ceiling Coatings: One of the most popular materials used with smooth finishes.
● Fire Protection: The fact that it is fire-resistant provides special advantages in wooden or steel structures and delays the spread of fire.
● Industries in Which It Finds Profound Utility
● Arts and Crafts: Widely used in the making/repairing of sculptures, molds, and decorations. They offer a vast opportunity for intricacies of detail and textures in art.
● Mold Making: It is widely used in the industry for making molds because of the elaborative details it picks out. Application areas include metal casting and manufacturing precision parts.
● Fossil and Replica Casting: This sophisticated modeling material is used in museum and research centers to make highly accurate replicas of fossils and archeological pieces.