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

Electronics devices and circuits, With the help of circuit diagram and the ...

With the help of circuit diagram and the waveforms,explain the working of a negative clipper with positive biasing voltage.also explain the Same concept in series clipper circuit

Evacuation of a high rise building - means of escape, Evacuation of a high ...

Evacuation of a high rise building - means of escape: Evacuation of a high rise building is likely to be split into two or more phases.  Initially, when the alarm activates (f

Architectural Design and Drawing, how can I improve my G+4 apartment with r...

how can I improve my G+4 apartment with rendering with pen and ink

Health care finance basic tool for nonfinancial managers, based on your man...

based on your managemet style or your personal perspective, discuss how you developed your viewpoint how it will influence the way you manage, and what challenges you migt face if

sweep effects, In the previous discussion, we investigated the static aero...

In the previous discussion, we investigated the static aeroelastic behaviour of straight (unswept) wings. These wings are characterised by an effective decoupling of wing bending a

Installing aircraft parts, Installing Aircraft Parts: Prior to fit remo...

Installing Aircraft Parts: Prior to fit remove the label from the engine and attach it to the paperwork for safekeeping. Check the engine over to ensure it is complete and chec

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

explain the fibre optic communication system with block diagram

External air tappings - aircraft engine , External air tappings: Engine...

External air tappings: Engines vary as to the number of external air tappings and their usage. The following notes are taken from the Pratt and Whitney JT9D but have been simp

Quality assurance and accreditation, how can i link quality assurance and a...

how can i link quality assurance and accreditation with a valid applicaion of my own work?

Corporate finance, An investment project provides cash inflows of $730 per ...

An investment project provides cash inflows of $730 per year for eight years. What is the project payback period if the initial cost is $3,500? What if the initial cost is $5,000?

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