DEFINITION
ALPHA GYPSUM is a common ingredient for making plaster. Alpha gypsum is made by processing gypsum stone into a fine powder and is well regarded for its strength and low absorptive levels.
DIFFERENCE PHYSICAL PROPERTIES
1.Hemihydrate gypsum has two forms: α and β, both of which are rhombic crystals, but their physical properties are different. α-type hemihydrate gypsum has good crystallinity and firmness. β-type hemihydrate gypsum is a flaky and cracked crystal with excellent crystals. Its specific surface area is much larger than that of α-type hemihydrate gypsum. When producing gypsum products, α-type semi-hydrated gypsum requires less water than β-type, and the products have higher compactness and strength.
2. With the continuous progress of hydration, β-type hemihydrate gypsum produces more and more colloidal particles of dihydrate gypsum. These particles are smaller than the original, have a large specific surface area, and absorb a lot of water; they continue to be hydrated and evaporated. Decrease, the consistency of the slurry continues to increase, the adhesion between colloidal particles is gradually strengthened, friction and adhesion between the particles are generated, and the slurry gradually loses its plasticity and gradually condenses.
DIFFERENT PRODUCTION PROCESS
Typically, α-type hemihydrate gypsum, also known as high-strength gypsum, is steamed in a saturated steam medium. The β-type hemihydrate gypsum, which is also construction gypsum, is calcined with a wok or an open device in a rotary kiln.
DIFFERENT USAGE
1. α gypsum powder high-strength gypsum is suitable for high-strength plastering projects, decorative products and gypsum board. It can be used in a high humidity environment after mixed with water repellent. It is made into a non-shrinking adhesive with the organic cementing agent. Organic materials, such as polyvinyl chloride alcohol aqueous solution and polyvinyl acetate emulsion, can be formulated as cementing agents. It is suitable for GRG, DIY plaster products, craft jewellery and various precision mould making.
2.β gypsum powder building is mixed with water and retarder to synthesize gypsum slurry, which can be used as indoor paint. Indoor plastering and stuccoing building gypsum mixed with water, sand and retarder to synthesize gypsum mortar used for indoor plastering. The plastered surface is smooth, delicate, white and beautiful. Gypsum mortar can also be used as a primer for paint, etc., and can be directly painted or pasted on wall coverings or wallpaper.
