To minimize turbulence and dross formation. To prevent aspiration of air or mould gases in the liquid metal stream. The term Green Sand denotes the presence of moisture in molding sand and indicates that the mold is not baked or dried.
A coal dust known as Sea Coal is added to control casting quality during expansion of the sand when hot metals are poured into the molds.
Prevent shrinkage cavities by improving casting structure Design a running gate system with risers that ensure a continuous flow of molten metal. Increase local heat dissipation by inserting internal chills, cooling ribs or cooling coils.
Reduce casting temperature to limit the total volume deficit. What are the disadvantages of casting process? It gives poor surface finish and mostly requires surface finish operation. Casting defects involves in this process. It gives low fatigue strength compare to forging. It is not economical for mass production. Casting can produce very complex geometry parts with internal Cavities. It can be used to make small few hundred grams to very large size part thousand of kilograms.
Any intricate shape can be Produced. The cause of tropical sprue is not known. It may be caused by persistent bacterial, viral, amoebal, or parasitic infections. Folic acid deficiency, effects of malabsorbed fat on intestinal motility, and persistent small intestinal bacterial overgrowth may combine to cause the disorder.
Tropical sprue is treated with antibiotics. This kills the bacteria overgrowth that results in this condition. Antibiotics may be given for a period of two weeks or one year. Tetracycline is the most commonly used antibiotic for treating tropical sprue. The name sprue derives from a Dutch word describing inflammation of the mouth, which is a frequent symptom. The disease has been recognized for more than years. It occurs mostly, but not exclusively, in the tropics.
Symptoms and Treatment. Advantages of Compression Molding It is a simpler process. It involves lower tooling costs. It is great for producing large items and thicker parts. It can be a good choice for insert molding and multi color molding. It is cost-effective for short production runs. It has a higher chance of post molding costs. Compression is a process under which volume of the system is gradually reduced, pressure and temperature increases where heat transfer may or may not be possible.
While in expansion process volume is gradually decrease with the decrease in pressure and temperature and heat transfer may or may not be possible. Injection molding is similar to compression molding, with both processes involving the use of heat and pressure. The difference is that injection molding moves the material through a screw and a hopper , whereas compression molding does not. Why sprue is tapered? Asked by: Jevon Metz. What is compression molding process?
What sprue means? Related questions. What is the purpose of strainer in the gating system? Which of the following gases is responsible for the Pin hole porosity in the molten metal? Which of the following can be the reason for the aspiration effect? Which of the following effects can produce porous castings? Which of the following reasons is the incorrect reason for the blow holes inside the castings?
Which of the following items is used for trapping impurities from entering the mould? Welcome to TalkJarvis QnA , a question-answer community website for the people by the people.
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