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

Design project, I need report explain every things about my project

I need report explain every things about my project

What are debentures?, What are debentures?  A Debenture is " A document ...

What are debentures?  A Debenture is " A document of contract of loans which is given under the organization's press and provides a venture that the debenture owner will get a s

Forgin exchange, The following exchange rates are available to you. (You ca...

The following exchange rates are available to you. (You can buy or sell at the stated rates.) Mt. Fuji Bank ¥85.00/$ Mt. Rushmore Bank SF1.356/$ Mt. Blanc Bank ¥64.74/SF Assume t

Air-system in aircraft engine, Air-System in Aircraft Engine: In the wo...

Air-System in Aircraft Engine: In the working cycle and airflow section we discussed the main airflow and working cycle of a gas turbine engine and found that a major function

Drafting, what employment options are available in drafting

what employment options are available in drafting

Describe any three properties of mortars, QUESTION 1 a) Describe any th...

QUESTION 1 a) Describe any three properties of Mortars b) Each combination of coarse and fine aggregates has a specific water demand for a given mix fluidity or slump. What

Duct with flow control-aircraft maintenance, Duct With Flow Control-Aircraf...

Duct With Flow Control-Aircraft maintenance: BERNOULLI'S THEOREM This theorem can be related to the relationship between pressure and velocity existing in the air flowing

Control surfaces , Control Surfaces  As with a flight control system...

Control Surfaces  As with a flight control system, a guidance algorithm uses control surfaces to control the behaviour of an airframe.         - Rudder, ailerons, elev

Electronics, design of a single stage amplifier

design of a single stage amplifier

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