Plaster molds, Other Engineering

Assignment Help:

           Plastic molds are made of plaster of Paris (gypsum) or calcium sulphate, talc and silica flour is added in the plaster of Paris to improve strength and to control the time required for the plaster to set. These ingredients are mixed with water and the resulting slurry is poured over the pattern.

           The plaster sets within 15 minutes usually. After the plaster sets, the pattern is removed and the mould is dried at 120°C -260°C to remove the moisture. The mould halves are assembled to form the mould cavity and are preheated to about 120°C. The molten metal is then poured into the mould.

           Patterns for plaster moulding are generally made of Aluminum, thermosetting plastics, brass or zinc alloys. Wood patterns are not appropriate for producing a large number of mould because they are repeatedly in contact with the water based plaster slurry.


Related Discussions:- Plaster molds

CRO, different types of switches used in CRO

different types of switches used in CRO

Changes in temperature and pressure-aircraft maintenance, Changes in temper...

Changes in temperature and pressure: The changes in temperature and pressure of the gases through a gas turbine engine are illustrated in Figure 1.5 The efficiency with which t

Tube drawing, Drawing operation can also be used for reducing the tube cros...

Drawing operation can also be used for reducing the tube cross-section. The drawing equipment consists of draw bench and die. One end of the tube is pulled through the die over a f

Theory of solar system, Expertsmind.com brings you unique solution in ele...

Expertsmind.com brings you unique solution in electrical engineering Define terms of Galaxy Clusters, Basic Astronomical Objects, Astronomical Distance Units, Terms

Aeroengine - velocity trinagle, If radial velocity is neglected, for a stat...

If radial velocity is neglected, for a stat or there is no change from the cascade analysis. For a rotor this vectorial For a rotor this vectorial addition gives rise to graphical

Corporate Governance, What is the status of corporate governance in UAE?

What is the status of corporate governance in UAE?

Mechanical pulverization, Mechanical pulverization method is applicable to...

Mechanical pulverization method is applicable to brittle metals like antimony. Many varieties of mechanical pulverizers are in use; some of these have counter rotating plates or r

Interference of light, Explain the formation of newton''s ring in reflected...

Explain the formation of newton''s ring in reflected light. Prove that the radius of the bright rings are proportional to the square root of the positive odd interger

Mechanical engineering how it works , i''m doing a project and need to kno...

i''m doing a project and need to know from start how engineering is structure? like a tree starting from its root

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd