Caution for operation of plaster 1:

1.石膏粉與水調合后，若發現水粉比例不合適時，應重取量調和。

1. After mixing gypsum powder with water, if the proportion of water powder is found to be inappropriate, the amount of gypsum powder should be reconciled.

2.攪拌的速度不宜過快，以免人為帶入氣泡，形成過多的結晶中心，導致石膏膨脹，強度降低。

2. The stirring speed should not be too fast, in order to avoid the artificial introduction of bubbles, forming too many crystallization centers, resulting in gypsum expansion and strength reduction.

3灌注模型時應從一側逐漸到另一側，震蕩灌注，排除氣泡，注滿各細微部分。

3. The filling model should be gradually from one side to the other, shaking filling, eliminating bubbles and filling the fine parts.

4石膏在凝固過程中存在體積膨脹

4. Volume expansion of gypsum during solidification

影響熟石膏凝固速度的因素有熟石膏粉的質量、熟石膏粉與水調合的比例不當、攪拌的時間和速度、水溫。

The factors affecting the solidification rate of ripe gypsum include the quality of ripe gypsum powder, improper mixing ratio of ripe gypsum powder to water, mixing time and speed, and water temperature.

5可以用建筑膠水調制。另則，也可以用免膠石膏粉，用水直接調制即可

5 can be modulated with building glue. On the other hand, it can also be made with glue-free gypsum powder, which can be directly mixed with water.

6水、石膏粉的混合比，水越多石膏凝固的時間越長，石膏密度越低；相反，水越多凝固時間越短，密度越大，牢度越高。水、石膏粉的混合比需要根據具體使用需求來控制

6. The mixing ratio of water and gypsum powder, the more water, the longer the solidification time of gypsum, the lower the density of gypsum; on the contrary, the more water, the shorter the solidification time, the higher the density and the higher the fastness. The mixing ratio of water and gypsum powder needs to be controlled according to the specific use requirements.

7攪拌時間越長，石膏凝固時間越快。一般而言攪拌到石膏粉非常均勻就可以澆鑄了，通常將攪拌時間控制在5分鐘內。澆鑄容器與石膏粉凝固時間的關系。澆鑄容器吸水與否影響著凝固時間，澆鑄容器不吸水鑄型凝固時間不變，反之，澆鑄入吸水容器內，凝固時間縮短。

7. The longer the stirring time is, the faster the solidification time of gypsum is. Generally speaking, it can be cast by stirring until the gypsum powder is very uniform, and the stirring time is usually controlled within 5 minutes. The relationship between casting vessel and solidification time of gypsum powder. Whether the casting vessel absorbs water or not affects the solidification time. The solidification time of the non-absorbent casting mould of the casting vessel remains unchanged. On the contrary, the solidification time is shortened when the casting vessel is poured into the absorbent vessel.