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

Solvency ratios and profitability ratios, Solvency Ratios: Profitability R...

Solvency Ratios: Profitability Ratios: The profitability ratios determine the capacity of the company to generate the profits with the amount of shareholders investment. Again hig

Static machines, briefly differenciate the moore & mealy machines

briefly differenciate the moore & mealy machines

Assgnment, Sulphuric acid can be made with concentration of 99%. However f...

Sulphuric acid can be made with concentration of 99%. However for different industrial process different concentrations are used. For a specific industrial requirement, 62% H2SO4

Electronic apu fuel control system in aircraft , Electronic APU fuel contro...

Electronic APU fuel control System in Aircraft : Electronic fuel control emulates the mechanical system, however it provides control in a slightly different way. The electronic

Development of surfaces, a hexagonal prism of 40mm side length of base and ...

a hexagonal prism of 40mm side length of base and height 80mm is resting on HP on its base with two edges of base is parallel to horizontal plane. A square hall of equally inclined

Students industrial work experience, Where are the recomended areas or indu...

Where are the recomended areas or industries where an Agricultural Engineering Student can apply for industrial training?

Firing order, FIRING ORDER If in multi cylinder engines, various cyli...

FIRING ORDER If in multi cylinder engines, various cylinders are made to fire one after the other, interference between adjacent cylinders would occur, since these may have o

Means of escape from trains - railway inspections, Means of escape from tra...

Means of escape from trains - railway inspections: The means of  escape from  trains is also considered  in  NFPA130.     Some  of  the considerations are: At least two eme

Clamper, what is clampers and how many types

what is clampers and how many types

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