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

Principle of means of escape - fire safety management, Principle of Means o...

Principle of Means of Escape: The means of escape with which a building is provided are simply the ways out of the building that can be safely used in the event of a fire.  It

Priority scheduling- operating system, Operating System Assignment# Priorit...

Operating System Assignment# Priority Scheduling leads to the risk of starvation: a process is ready, but never is given the processor. Some preemptive priority schedulers therefor

Assembly buildings - common fault, Assembly buildings - fire risk assessmen...

Assembly buildings - fire risk assessment: Common faults found in assembly buildings are: Combustible items left in protected routes or bedroom corridors Locked exi

Research paper, You will research an issue relating to money and banking. Y...

You will research an issue relating to money and banking. You will write an eight- to 10-page paper discussing your research, in depth. You will also need to relate your research t

Bonds, Objective: Students should familiarize themselves with bonds and/or ...

Objective: Students should familiarize themselves with bonds and/or preferred stock as an investment opportunity and as a source of funds. In this assignment students will determin

What is eft?, What Is EFT? EFT is short for Electronic Funds Transfer in...

What Is EFT? EFT is short for Electronic Funds Transfer in finance. An EFT is a method of transferring money from one bank account directly to another account without any paper

The integrator, Integrator This circuit performs the calculus operation...

Integrator This circuit performs the calculus operation of integration. An operational amplifier with negative feedback applied via a capacitor (instead of a resistor) will pe

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