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

Communication engineering, I am preparing for a seminar ... but I am search...

I am preparing for a seminar ... but I am searching for a very good topic. Can you help me to get a topic in wireless communication . i want to know what are the latest technologie

Chemistry, what is the role of chemistry in engineering

what is the role of chemistry in engineering

Electronic engine control systems - aircraft engine, Electronic engine cont...

Electronic engine control systems : Advances in gas turbine technology have demanded more precise control of engine parameters than can be provided by hydromechanical fuel cont

Welding, why is it important to only strike the arc in the weld joint

why is it important to only strike the arc in the weld joint

Hot and cold working, advantages and disadvantages of cold and hot working

advantages and disadvantages of cold and hot working

Damage limits and repair in cold section inspection , Damage Limits and Rep...

Damage Limits and Repair Minor damage to compressor and fan blades may be repaired provided the damage is within the allowable limits established by the manufacturer in the AMM

Vehicle handling and control, Your objective in this lab is to convince the...

Your objective in this lab is to convince the assessor that you understand the basic concepts of how shock absorbers affect the ride and handling of a vehicle.  This will involve d

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