Plaster board, also known as drywall or sheetrock, is a widely used material for wall coverings in construction. It is made up of gypsum board, which is sandwiched between two layers of liner. The liner is typically made of plaster board, and it plays a crucial role in providing strength and stability to the overall structure.

During the production of gypsum board, wet gypsum is spread onto the first liner, and then the second liner is set on top of the wet gypsum. This process ensures that the gypsum adheres well to the liner and forms a solid and durable wall covering. The basis weight of plaster board typically ranges from 200 to 300 g/m2, providing a sturdy and reliable foundation.

One of the key features of plaster board is its use of various recycled fiber types. The top ply, for example, can be made from old newsprint. This not only helps in reducing waste and promoting sustainability but also adds to the strength and durability of the plaster board. The base ply furnish, on the other hand, can be a mixture of OCC (old corrugated containers), old newsprint, and broke (waste paper).

When it comes to plaster board, high machine directional tensile strength is crucial. This is because gypsum boards are typically lifted from the shorter end when constructing walls. The plaster board needs to be able to withstand this handling without tearing or losing its structural integrity. Additionally, a certain level of porosity is required for proper adhesion of the gypsum to the liner. This ensures that the gypsum board remains firmly attached to the plaster board and does not peel off over time.

Overall, plaster board is an essential component in the construction industry. Its use as a liner for gypsum board provides strength, stability, and durability to wall coverings. By incorporating recycled fiber types, it also contributes to sustainability efforts. The high machine directional tensile strength and proper porosity level ensure that plaster board performs optimally in its role as a liner for gypsum board.

In conclusion, plaster board is a versatile and indispensable material in the construction of walls. Its use as a liner for gypsum board enhances the overall strength and durability of wall coverings. With the incorporation of recycled fiber types and attention to machine directional tensile strength and porosity, plaster board continues to be a popular choice for wall coverings in the construction industry.