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

Tool life, hi I''m doing research in tool life of solid carbide endmills ...

hi I''m doing research in tool life of solid carbide endmills and I was looking at your formulas. I was wondering if tell me or where I can find the data required for these formu

Water traetment, what are the different phosphates used in water treatment?...

what are the different phosphates used in water treatment?

Programming, A charitable organization wants to design a special ATM machin...

A charitable organization wants to design a special ATM machine to be used by needy people. The association supplies the needy person with a pin number to be able to use the ATM

Capital budgeting process, Capital budgeting process: When investing in a l...

Capital budgeting process: When investing in a long term assets, the project has been evaluated in term of its profitability and expected cash flow in the future. The capital budge

Oscilloscope, connecting probe in CRO causes

connecting probe in CRO causes

Starting worki in ccs.., 1- plot and creat x1(t)=4exp(t/5),x2(t)=Sin(2pift+...

1- plot and creat x1(t)=4exp(t/5),x2(t)=Sin(2pift+Pi/2) 2-write a c fucntion to compute convolution of n2 finite series ands plot 3-implemet an FIR filter in c in CCS

Fire safety management for commercial buildings, fire safety management for...

fire safety management for Commercial buildings: Commercial buildings where all the occupants are familiar with the building we also need to see evidence of satisfactory fire

Zeroth law of thermodymanics, Explain with the aid of sketch of zeroth law ...

Explain with the aid of sketch of zeroth law of thermodynamics

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