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

The research about thermoset polymer products, Chemical Engineering The re...

Chemical Engineering The research about thermoset polymer products. For example Polyimide Film Thermosetting and Pressure-Sensitive Adhesive Tape.

..Evans Diagram, would you help with Evans diagram( draw and explain) for I...

would you help with Evans diagram( draw and explain) for Iron in seawater,and how variability of Oxygen concentration affect the electrode potential vs.current?

Fibre optics communications, explain the fibre optic communication system w...

explain the fibre optic communication system with block diagram

Construct the element matrix numerically using the 2, 1. The cantilever bea...

1. The cantilever beam-like structure shown below is modeled using a 2 x 10 mesh of rectangular four-node plane stress elements of equal size. Geometric boundary conditions at x ?

Determine the data rates for different modulation, Question: (a) OFDM s...

Question: (a) OFDM signals have a higher PAPR that signal carrier signals do. Describe (i) Why this is so and what is the impact on radio transmission systems? (ii) How

Depreciation methods in economical engineering, Depreciation Methods T...

Depreciation Methods Technically speaking, U.S. tax law permits deduction from taxable income of a reasonable allowance for wear or tear, natural decay or decline, exhaustion,

Field effect transistors, FIELD EFFECT TRANSISTORS (FET) A field-effect...

FIELD EFFECT TRANSISTORS (FET) A field-effect transistor (FET) is a semiconductor device in which the current flowing through a conduction channel i.e. between two terminals ca

Combustion process, Combustion process: Air from the engine compressor ...

Combustion process: Air from the engine compressor enters the combustion chamber at a velocity up to 500 feet per second, but because at this velocity the air speed is far too

Skin-core debonding in sandwich structures, If the skins are peeled from th...

If the skins are peeled from the core, a sandwich structure loses its strength and stiffness. This can occur under - wave-slamming in fast ferries - rapid depressurisati

Calculate the relative load of mobile broadband subscribers, Question: ...

Question: (a) A mobile operator wants to weigh and allocate cost towards mobile broadband subscribers with mobile broadband at 80% of the traffic and 15% of the subscribers. H

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