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

International finance, at the beginning of year 1 the terranian central ban...

at the beginning of year 1 the terranian central bank conducted k100 million of dollar selling/terranian kwacha buying intervention. The intervention was undertaken at the rate of

Arinc decoding word, how to decode arinc 429 words and send result to pc by...

how to decode arinc 429 words and send result to pc by rs232 bus

Light-emitting diode, Light-emitting diode: One of the most common ligh...

Light-emitting diode: One of the most common light sources used in electronics is the "Light Emitting Diode" (LED).  A LED is a two terminal semiconductor device comprising a p

Match plate patterns, Match plate patterns are used where a rapid producti...

Match plate patterns are used where a rapid production of small and accurate castings is desired on a large scale. These patterns find a great favour in machine moulding. Their co

Engineering physics, when same music is played in veena and violin , we sha...

when same music is played in veena and violin , we shall hear the sound of

The world of fiance, Answer the following questions: What are the three for...

Answer the following questions: What are the three forms of a business organization? What are the advantages and disadvantages of each form? For a corporation, what is the overall

Derivatives- vertical spread, Let C (K ) denote a European vanilla Call opt...

Let C (K ) denote a European vanilla Call option with strike price K . Assume that all options are identical except for strike price, and strike prices satisfy K ??Question 1 [5 m

Signal conditioning amplifier, Signal conditioning amplifier The primar...

Signal conditioning amplifier The primary function of the signal conditioning amplifier is to match the output signal range of the transducer to the input signal range of the a

#title: Signal Processing, how to load a large file consisting hex bytes wi...

how to load a large file consisting hex bytes without spaces and plot the required bytes

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