Overview of gypsum-based building materials: gypsum boards, panels and sheets

Gypsum is most widely used in the production of such industrial prefabricated elements as partition panels, floor covering boards, partition boards and coasting boards.

Partition panels are made with a height that is usually equal to the floor height. The width of the panels either corresponds to the size of the room, or is a certain standard value that allows you to build partitions of any length, connecting the panels to each other. By their design, gypsum panels are divided into reinforced and non-reinforced, having an opening and blind. In accordance with the purpose, there are two types of gypsum boards — interior and inter-apartment.

Gypsum concrete panels are produced on a rolling mill, in vertical or horizontal shapes. The material is a mixture of gypsum, sand and sawdust in a ratio of 1:1:1, having a water-gypsum ratio of 0.57-0.6. To lighten the weight of partition plates, foam can be introduced into the mass. The range of panel sizes usually falls within the following overall ranges: height — 2.4-3.1 m, width — 1.5-6 m, thickness — 8-12 cm. Also, the rolling mill produces slabs based on gypsum-cement-pozzolan binder — such products can be used as wall panels for external walls and as bases for floors.

The production process of all types of gypsum concrete panels is approximately the same: a rack-and-pinion frame with metal loops for gripping is laid on the moving rubber band of the rolling mill. The stacking mechanism feeds the gypsum mixture to the frame, which is rolled between the molding belts. The molded panel continues its way along the intermediate conveyor and gets into the edger — during this time, the gypsum has time to harden. At this stage, the panel is turned from a horizontal position to a vertical one and sent to the drying chamber.

Reinforcing materials and specialized additives introduced into the composition of gypsum dough depend on the purpose of the boards produced. For example, slabs that will be used as a roll in floors are reinforced with a torn mesh, reeds, and a rack-and-pinion frame. And the field of application of gypsum concrete slabs with the addition of wood pulp or asbestos-cement waste is the construction of load-bearing partitions in buildings where regular moisture is prevented.

Thin gypsum sheets, sometimes called dry plaster, are made in the form of gypsum fiber sheets directly, or in the form of a gypsum core, pasted on both or one side with cardboard. Gypsum sheets are used for interior decoration of rooms with wooden or stone surfaces, as well as for the production of door panels. And gypsum sheets glued with bitumen mastic in several layers are used for preparing floors and bases for rolled roofs. As a rule, the dimensions of gypsum sheets are 2.7-3.3 m long, 1.2 m wide, 8-10 mm thick.

Conveyor production of gypsum sheets covered with cardboard includes several basic operations:

• preparation of gypsum concrete mortar,
• supply and distribution of gypsum concrete mortar on the lower paper layer, which, rolling out of the roll, moves along the conveyor,
• overlay of the top layer of paper on the gypsum core,
• pruning, bending and gluing the side edges of the lower paper sheet to close the edge,
• cutting raw hardened sheets and drying them on a conveyor dryer,
• transportation to the warehouse for further sale.

Another type of gypsum concrete sheets, which should not be overlooked, is gypsum fiber sheets without cardboard. This type of material is produced by introducing 10-12% reinforcing fiber into the molding gypsum concrete mass.