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

Shrinkage cavities casting defects, Q.   Discuss briefly the causes and rem...

Q.   Discuss briefly the causes and remedies of Shrinkage cavities casting defects.                                                 OR  Why shrinkage cavities are caus

Organic, What happened when melonic acid heated

What happened when melonic acid heated

Parmpreet, Hi, i want to get a quote for my communication networks assignme...

Hi, i want to get a quote for my communication networks assignment

DSP, bit reversed process 10 point dft

bit reversed process 10 point dft

Density correction factor, superheated steam flow measurement please provid...

superheated steam flow measurement please provide formula used for density correction factor

Genetic algorithm procedure, Genetic Algorithm Procedure Generate a ...

Genetic Algorithm Procedure Generate a "pool" of "genes" randomly These genes are then "mated" to produce the "mated" to produce the next generation Best genes have a

Asteroid belt, Why is there an asteroid belt? - Rocky planetismals survive...

Why is there an asteroid belt? - Rocky planetismals survived in the asteroid belt between Mars and Jupiter because they did not grow together into a planet. - Jupiter’s gravity, t

Econometrics coursework, Hello this is Lee, I have an Econometrics coursewo...

Hello this is Lee, I have an Econometrics coursework to be helped by some experts from your company. Please send me your reply asap Lee

Engine torque, ENGINE TORQUE It is the force of rotating action about t...

ENGINE TORQUE It is the force of rotating action about the crankshaft axis at any given instant of time. It is given by,

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