We have expertise to make moulds using the following processes:
» No bake process
Sand molds are created using a wood, metal or plastic pattern. The pattern can be a dump box, match plate, or a loose piece. Sand is mixed with a urethane binder in a high speed mixer. This sand is deposited into box containing the pattern and all essential gating, risers and chills for pouring. The sand mixture sets up hard in a few minutes and the mold is removed from the pattern. Cores for forming internal passages in the castings are made using the same process.
The molds and cores are cleaned and sprayed with a refractory coating. This coating shields the molten metal from direct contact with the sand and seals the sand grain for better surface finish.
Cores are carefully placed into the molds. The molds are then closed and are ready for pouring.
Melting for both investment and sand casting is performed using electric induction furnaces. Two 400 pound capacity box furnaces handle the larger pours. A smaller lift coil with a 200 pound capacity is used for alloys with lower melting points such as aluminum and brass. It is also used for smaller pours of non-ferrous alloys to reduce waste. All alloys are QC checked on our spectrometer prior to pouring and adjusted to insure conformance with specifications.
Investment shells are pre-heated in a kiln before pouring to insure proper filling and minimize casting defects.
The molten metal from the box furnace is poured into a pre-heated ladle that is used to pour the molds. The lift coil furnace melts alloys in a crucible that is also used for pouring. The use of separate crucibles for each base alloy prevents cross contamination of the metals.
Ceramic and glass cloth filters are used in each mold to eliminate impurities and inclusion from the metal as it is cast.
» Green Sand Casting Process
GREEN SAND MOLDING is the most commonly used casting platform throughout the entire Casting Industry, World Wide. Simply put, there is a top, a bottom, and a middle to a mold. The pattern, or impression device, sits in the middle of the mold, and later is surrounded with sand . These are the basic, universal casting components, which can be applied to all casting processes.
The top and the bottom of the pieces of the mold form the flask. The flask assembly, the top and bottom, "holds the whole thing together". The upper or topmost section of the flask of the mold (flask) is called the cope, while the bottom of the mold (flask) is called the drag. The impression device, in the middle, is called the pattern. The sand around the pattern is called the, holding medium. The mold maker uses the pattern to make the impression in the sand. He then sets the pattern aside. At that point, the molder closes the cope and drag, forming the mold. What the mold maker wants is the void left from the impression of the pattern, in middle of the sand, inside the mold. So, he fills that void with a molten material.
Basic casting like this, is also called, "Green Sand Molding, or Green Sand Casting". These are the most basic molding methods, currently used in today’s casting practices, regardless of the metal alloy, or any molten - liquid material being poured. Like was said in the Preface, Man has been casting things since before Biblical times, using these very concepts.
All casting techniques employed in the rest of the Casting and Molding Processes are in many ways, just like sand casting, or green sand molding. With some thought and imagination, you can always see the cope and drag principle of casting we already discussed. The different techniques or casting and molding processes are used to achieve a desired end product, which has a special need in the market place. This special need prompted man to develop special processes.
Examples of usage would be: Air movement components (fan blades), hubs, shafts, tubes, rectangles, squares, holes, no holes, the list is endless.
Most of our manufacturing is done using no bake process, which gives finished products with better quality.
We have one two-ton Dual Port Induction furnace and seven coal fired “cupola” furnaces of diameters ranging from 21 inches to 36 inches.
The salient features of our casting process are:
» Use of special grade pig iron with high silicon content
» Use of special grade cast iron scrape that is collected from a ship-breaking yard
» Installation of instant ferro labs at each furnace to (a) monitor content of carbon, silicon, and manganese, in the metal and (b) measure its temperature and tensile strength.
The salient features of our casting process are: » Use of special grade pig iron with high silicon content » Use of special grade cast iron scrap that is collected from a ship-breaking yard Installation of instant ferro labs at each furnace to (a) monitor content of carbon, silicon, and manganese, in the metal and (b) measure its temperature and tensile strength.
We have a small pattern shop for maintenance of our customers’ patterns. We do not make patterns but if required we can arrange for
pattern making from some of the best firms in India.
We also have forklifts and other facilities for ensuring efficient loading of finished products into containers inside our own factory.