Dentalhartgips is a formulated hemihydrate plaster (CaSO4.½H20) produced from naturally occurring gypsum mineral. This product is a formulated dental stone used during the flasking operation in denture manufacturing and also to produce antagonistic or opposing. Dental Hartgips is available in white, yellow, green or blue in colour.
Base plaster for Type 3
Very high strength
| Mechanical Properties | |
|---|---|
| Brinell Hardness (MPa) | 180 |
| Dry compressive strength (Mpa) | 52 |
| Wet Compressive strength (Mpa) | 24 |
| Chemical Properties | |
|---|---|
| Chemical Composition | CaSO4.½H2O |
| Chemical Name | Calcium Sulphate Hemihydrate |
| Colour | White, Blue, Yellow, Green |
| Setting Parameters | |
|---|---|
| Final setting time (minutes) | 10-14 |
| Linear Expansion (%) | 0.18 |
| Working time (minutes) | 4-8 |
| Physical Properties | |
|---|---|
| Loose bulk density (kg/m³) | 1200 |
| Particle Size Distribution (mesh size and % weight retained) | > 0.04% at 200 µm | > =4% at 90 µm |
| Plaster to Water Ratio | |
|---|---|
| Plaster to water mix ratio (by weight) | 100/30 |
| Plaster to Water Ratio (by weight) | 3.33:1 |
| Water to plaster ratio ( by weight) | 30% |
Mixing utensils should always be clean and free of set plaster. Use clean water only. For consistent results, attention must be given to the correct proportioning and mixing of the plaster and water.
Add the weighed quantity of plaster slowly into the measured volume of water and allow to soak from 30 seconds to 60 seconds. Stir vigorously with a spatula for 30 seconds to 60 seconds to obtain a uniform mix. If mechanical mixing is used with or without vacuum, the mixing time will be much less than that for hand mixing. The time will be dependent on the type of mixer paddle and speed.
To obtain very fine detail and to exclude air bubbles, the plaster should be vibrated into the impression. The fluidity of the mix can be increased by increasing the proportion of water, however this will result in reduced strength and hardness.
Do not mix fresh plaster with that which has been mixed for some time previously.
Packaging available : 25 kg
Shelf life : 6