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

FOCP, THE USER INTERFACE

THE USER INTERFACE

Prepare a short document to sensitise public, Since the introduction of mob...

Since the introduction of mobile phones and other smart devices, concerns (both scientific and public) have been raised about the potential health impacts from regular use. Numerou

Alternative escape routes - means of escape, Alternative escape routes: ...

Alternative escape routes: Does everyone have access to the alternative routes or do some people have no choice about which way they go? Are all the escape routes

Combustion section - aircraft engine, Combustion section: The combustio...

Combustion section: The combustion chamber has the difficult task of burning large quantities of fuel, supplied through the fuel burners, with extensive volumes of air, supplie

Servo accelerometer, Servo accelerometer Electro-mechanical servo (forc...

Servo accelerometer Electro-mechanical servo (force balance) accelerometer uses an electromagnet to provide restoring force. The position of the seismic mass is measured by a p

An essay on power train, Interior noise is basically airborne or structure-...

Interior noise is basically airborne or structure-borne. The excitation sources of vibratation and noise from engines can be divided as mechanical, combustion, and flow sources.

Int. finance management, Discuss the roles of international financial syste...

Discuss the roles of international financial system in international business

Tensile strength of core materials , The tensile strength of the core mate...

The tensile strength of the core material in a sandwich structure can be determined using the flat-wise tension fixture shown below. The sandwich is bonded between two al

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