Plaster of paris | Definition, Uses, & History (2024)

FAQs

What is Plaster of Paris and its uses? ›

It is commonly used to precast and hold parts of ornamental plasterwork placed on ceilings and cornices. It is also used in medicine to make plaster casts to immobilize broken bones while they heal, though many modern orthopedic casts are made of fibreglass or thermoplastics.

Plaster of Paris was well known as a building material for many centuries before it was introduced as casting material. Egyptians as well as Romans used it for plastering walls however not more is known on plaster use after the end of Roman occupation.

Plaster of Paris (POP) Is known as calcium sulphate hemihydrate (CaSO₄. 1/2 H₂O). It is prepared by heating calcium sulphate dihydrate (CaSO₄ . 2H₂O) or gypsum.

Gypsum plaster (plaster of Paris)

Gypsum plaster, also known as plaster of Paris, is a white powder consisting of calcium sulfate hemihydrate.

Plaster of Paris when mixed with water and applied around the fractured limbs, sets into a hard mass and keeps the bone joints in a fixed position. So, it is commonly used for setting fractured bones.

Plaster of Paris is a very popular chemical substance that is mostly used for sculpting and also in gauze bandages. We all know that the plaster of Paris is used by doctors to support fractured bones, it is also used in the construction industry, in making casts for statues and making designs for ceilings.

Gypsum on heating turns into a white powder which is what we call Plaster of Paris, and on mixing this with water it turns into a gypsum paste which is used in false ceilings, wall surfaces, as fireproof agents, etc.

plaster, a pasty composition (as of lime or gypsum, water, and sand) that hardens on drying and is used for coating walls, ceilings, and partitions. Plastering is one of the most ancient building techniques.

Plaster of paris is now not a water-resistant substance. It is a notably dry and porous substance. Whenever it is uncovered in water, it will soak up it. Plaster of Paris is an extraordinarily porous cloth when dried, and as such, will take in any new water that touches its surface.

Why does plaster of Paris crack? ›

There are several reasons why this happens. Cracks can be the result of thermal movement, the settling of a foundation or sill work, or even exposure to moisture for an extended period of time. The extent of the crack can also vary across different plastering types.

The history of plaster of Paris is long and enduring—it can be traced back to ancient Egypt. In the well-known civilization along the Nile, they used plaster of Paris to make sculptures and to decorate their homes. The Romans also used it to make buildings and to repair damaged objects.

Consuming plaster of Paris (POP) can be extremely dangerous and toxic. It can lead to serious health complications including gastrointestinal obstruction irritation and damage to the digestive system. There is also a risk of developing infections due to the disruption of the gastrointestinal tract's normal functioning.

The primary difference between white cement and POP (Plaster of Paris) is their composition. White cement is made from limestone and clay, while Plaster of Paris is made of gypsum. As far as the strength goes, cement is stronger when compared to Plaster of Paris.

The primary difference between gypsum and Plaster of Paris is that calcium sulphate dihydrate is found in the gypsum, whereas calcium sulphate hemihydrates are contained in the Plaster of Paris. A naturally occurring mineral is gypsum. This is thus the biggest distinction between plaster of paris and gypsum.

In many countries, this material is so commonly used because it is a lightweight material that has high fire resistance that adds more to the popularity of POP. It is a dry powder that is mixed with water to make a thick paste that can be further used to put some designs on the wall.

Plaster of paris is now not a water-resistant substance. It is a notably dry and porous substance. Whenever it is uncovered in water, it will soak up it. Plaster of Paris is an extraordinarily porous cloth when dried, and as such, will take in any new water that touches its surface.

After 1 hour remove the dried Plaster of Paris from the mold. Allow the cast to dry 1 to 3 hours depending on size.