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Introduction Of The Chemical Properties Of Hydrocolloid Plaster
Sep 15, 2017

     The main compositions of gypsum and high strength gypsum are β-type semi water gypsum and α-type half water gypsum, which are mixed with water, and the gypsum will be hydrated to produce dihydrate gypsum, releasing heat and hardening into hardened body with a certain strength.Hydrocolloid Plaster

     The half water gypsum is dissolved first and then hydrated to produce dihydrate gypsum; because the solubility of dihydrate gypsum is lower than that of semi-water gypsum, the two-water gypsum is precipitated from the saturated by colloidal particles. Because of the precipitation of dihydrate gypsum, the balance of the dissolution of the half water gypsum is destroyed, and the semi water gypsum continues to dissolve and hydrate. So continuously the dissolution of the half water gypsum and the separation of the dihydrate gypsum until the half water gypsum is exhausted. In the above process, the free water in the gypsum slurry decreases gradually due to hydration and evaporation, and the slurry gradually thickens.Hydrocolloid Plaster

    Gypsum Quick Sticky powder Use note: Before the device must be the above the putty shovel off, and also to avoid the cement mortar outflow, so will appear gypsum line drop. In the use of glue must pay attention to the use of available, so can avoid in the process of use to form waste. After the installation is sure to pay attention to vigorously press, so that the plaster line will be posted more tight. The next step is to deal with a good plaster line, and pay attention to it must be done in a completely boring condition.Hydrocolloid Plaster

    And loses plasticity, this process is called condensation. Subsequent。 The slurry continues to thicken, and the gypsum gradually condenses into crystals, and gradually grows, coexists and staggered to form a crystalline structure network. In this process, the slurry gradually hardened, the strength increased, forming a certain intensity of the hardening, until completely dry, the strength stopped growing. This process is called hardening.Hydrocolloid Plaster

    The theory of hydration reaction of semi-hydrated gypsum water meter is 18.6% of its weight, in use in order to make the slurry have enough fluidity. The usual water volume is much larger than the theoretical water requirement: Therefore, the hardened gypsum slurry contains a large amount of pores. Hydrocolloid Plaster

   The β-type half water gypsum in the building gypsum is flaky and fractured crystals, the grain is small, the specific surface area is large, the water requirement is $number, so the pore rate after hardening is large and the strength is low. and high strength gypsum. Semi-water gypsum crystallization good, coarse grain, small specific surface area, modulation into a plastic paste, the water demand is about $number, after hardening the porosity is small, thus has a higher strength.Hydrocolloid Plaster