title: A new phosphate bonded investment.
abstract: A new type of phosphate bonded investment has been studied. The setting expansion was found to be 0.03-0.05%, the thermal expansion was 1.54-1.85% depending upon the mixing liquid used: water or aqueous glycerol solutions, 5, 10, or 20%. Trial castings of alloys with a thermal expansion room to solidus temperature ranging from 1.60 to 1.91% showed either a very high accuracy or the possibility of improving the accuracy actually found by modifying the glycerol content of the mixing liquid used. To prevent cracking, heating of the investment mould in the temperature range 200-300 degrees C must be slow, probably not faster than 2-3 degrees per min.
mesh_terms: D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003734:Dental Casting Investment; D003735:Dental Casting Technique; D006358:Hot Temperature; D010710:Phosphates; D013499:Surface Properties
chemical_list: D003734:Dental Casting Investment; D010710:Phosphates