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

Vertical spread, What are the no-arbitrage lower bound, and the no-arbitrag...

What are the no-arbitrage lower bound, and the no-arbitrage upper bound, of the vertical spread

Levelling Theory and Computation, Two readings i.e., 1.64m, and 0.73m, were...

Two readings i.e., 1.64m, and 0.73m, were taken during leveling procedure to define the slope of centerline of a bridge at points A, and B. If distance AB = 50m, find the slope of

Thermodynamics, What are the importance of engineering thermodynamics

What are the importance of engineering thermodynamics

Chemistry, explain elecrochemical series and give its applications

explain elecrochemical series and give its applications

Guidance laws , The guidance law is used to generate a requirement (usually...

The guidance law is used to generate a requirement (usually an required acceleration) that will achieve the guidance objective. In this course, we will look at three main types

Marginal costing, VK Ltd a multi-product Company, furnishes you the followi...

VK Ltd a multi-product Company, furnishes you the following data relating to theyear 2000.First Half of the year Second Half of the yearSales Rs. 45,000 Rs. 50,000 Total Cost Rs. 4

Quantitative, Case 1: Decision Analysis Flifla sells tomatoes every day in...

Case 1: Decision Analysis Flifla sells tomatoes every day in Suk al Marqazi, the downtown fruit and vegetable market. He finds that he can order tomatoes in crates of 25 kg and he

Avionic systems design- static stability derivatives, Static stability der...

Static stability derivatives Static stability requires that a restoring action to any motions caused by forces and moments is auto-matically produced along and about the same a

Themodynamic, 1 kg of air is allowed to expand reversibly in a cylinder beh...

1 kg of air is allowed to expand reversibly in a cylinder behind a piston in such a way that the temperature remains constant at 260 degree while the volume is doubled.The piston i

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