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

Roof bolt support performance, A certain coal mine has weak layer comprisin...

A certain coal mine has weak layer comprising of 10cm, 11cm, 9cm, 12cm, 15cm , and 19cm of inter laminated shales and mudstone. Design a full column resin bolt support system if th

Quine mecluskey tabulation algorithm, simplify using quine Mccluskey tabula...

simplify using quine Mccluskey tabulation algorithm and find out the number of primes implicants f(a,b,c,d)=(2.3,4,5,13,15)+d(8,9,10,11) in logic design

Inlet duct arrangement in aircraft engine, Inlet duct arrangement in Aircra...

Inlet duct arrangement in Aircraft Engine: Wherever the APU is located, ducting will be required to bring air to the APU inlet. In figure 18.9. we can see that the inlet duct

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

Aeroengines - grid conversion, When we solved our simple problem we saw tha...

When we solved our simple problem we saw that the truncation error was O(x) We therefore expect that as the number of grid points is was O(x). We therefore expect that as the numbe

Tabular method, Ask question #Minimumsolve the following convolution in tab...

Ask question #Minimumsolve the following convolution in tabular form X(n)={1 2 -3 4 } h(n)={1 2 3 4 } 100 words accepted#

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